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Parts and Accessories Necessary for Safe Operation

TITLE 49--TRANSPORTATION

CHAPTER III--FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

PART 393--PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION
 
Sec. 393.1 Scope of the rules of this part.

Source: 53 FR 49384, Dec. 7, 1988, unless otherwise noted.

Every employer and employee shall comply and be conversant with the
requirements and specifications of this part. No employer shall operate
a commercial motor vehicle, or cause or permit it to be operated, unless
it is equipped in accordance with the requirements and specifications of
this part.

Sec. 393.3 Additional equipment and accessories.

Nothing contained in this subchapter shall be construed to prohibit
the use of additional equipment and accessories, not inconsistent with
or prohibited by this subchapter, provided such equipment and
accessories do not decrease the safety of operation of the motor
vehicles on which they are used.

Sec. 393.5 Definitions.

As used in this part, the following words and terms are construed to
mean:

Aggregate working load limit. The summation of the working load
limits or restraining capacity of all devices used to secure an article
of cargo on a vehicle.

Agricultural commodity trailer. A trailer that is designed to
transport bulk agricultural commodities in off-road harvesting sites and
to a processing plant or storage location, as evidenced by skeletal
construction that accommodates harvest containers, a maximum length of
28 feet, and an arrangement of air control lines and reservoirs that
minimizes damage in field operations.

Anchor point. Part of the structure, fitting or attachment on a
vehicle or article of cargo to which a tiedown is attached.

Antilock Brake System or ABS means a portion of a service brake
system that automatically controls the degree of rotational wheel slip
during braking by:

(1) Sensing the rate of angular rotation of the wheels;

(2) Transmitting signals regarding the rate of wheel angular
rotation to one or more controlling devices which interpret those
signals and generate responsive controlling output signals; and

(3) Transmitting those controlling signals to one or more modulators
which adjust brake actuating forces in response to those signals.

Article of cargo. A unit of cargo, other than a liquid, gas, or
aggregate that lacks physical structure (e.g., grain, gravel, etc.)
including articles grouped together so that they can be handled as a
single unit or unitized by wrapping, strapping, banding or edge
protection device(s).

Bell pipe concrete. Pipe whose flanged end is of larger diameter
than its barrel.

Blocking. A structure, device or another substantial article placed
against or around an article of cargo to prevent horizontal movement of
the article of cargo.

Bracing. A structure, device, or another substantial article placed
against an article of cargo to prevent it from tipping, that may also
prevent it from shifting.

Brake. An energy conversion mechanism used to stop, or hold a
vehicle stationary.

Brake tubing/hose. Metallic brake tubing, nonmetallic brake tubing
and brake hose are conduits or lines used in a brake system to transmit
or contain the medium (fluid or vacuum) used to apply the motor
vehicle's brakes.

Bus. A vehicle designed to carry more than 15 passengers, including
the driver.

Chassis. The load-supporting frame in a truck or trailer, exclusive
of any appurtenances which might be added to accommodate cargo.

Clearance lamp. A lamp used on the front and the rear of a motor
vehicle to indicate its overall width and height.

Container chassis. A semitrailer of skeleton construction limited to
a bottom frame, one or more axles, specially built and fitted with
locking devices for the transport of cargo containers, so that when the
chassis and container are assembled, the units serve the same function
as an over the road trailer.

Converter dolly. A motor vehicle consisting of a chassis equipped
with one or more axles, a fifth wheel and/or equivalent mechanism, and
drawbar, the attachment of which converts a semitrailer to a full
trailer.

Curb weight. The weight of a motor vehicle with standard equipment,
maximum capacity of fuel, oil, and coolant; and, if so equipped, air
conditioning and additional weight of optional engine. Curb weight does
not include the driver.

Dunnage. All loose materials used to support and protect cargo.

Dunnage bag. An inflatable bag intended to fill otherwise empty
space between articles of cargo, or between articles of cargo and the
wall of the vehicle.

Edge protector. A device placed on the exposed edge of an article to
distribute tiedown forces over a larger area of cargo than the tiedown
itself, to protect the tie-down and/or cargo from damage, and to allow
the tiedown to slide freely when being tensioned.

Emergency brake system. A mechanism designed to stop a vehicle after
a single failure occurs in the service brake system of a part designed
to contain compressed air or brake fluid or vacuum (except failure of a
common valve, manifold brake fluid housing or brake chamber housing).

Fifth wheel. A device mounted on a truck tractor or similar towing
vehicle (e.g., converter dolly) which interfaces with and couples to the
upper coupler assembly of a semitrailer.

Frame vehicle. A vehicle with skeletal structure fitted with one or
more bunk units for transporting logs. A bunk unit consists of U-shaped
front and rear bunks that together cradle logs. The bunks are welded,
gusseted or otherwise firmly fastened to the vehicle's main beams, and
are an integral part of the vehicle.

Friction mat. A device placed between the deck of a vehicle and
article of cargo, or between articles of cargo, intended to provide greater
friction than exists naturally between these surfaces.

Fuel tank fitting. Any removable device affixed to an opening in the
fuel tank with the exception of the filler cap.

g. The acceleration due to gravity, 32.2 ft/sec\2\ (9.81 m/sec\2\).
Grommet. A device that serves as a support and protection to that
which passes through it.

Hazard warning signal. Lamps that flash simultaneously to the front
and rear, on both the right and left sides of a commercial motor
vehicle, to indicate to an approaching driver the presence of a
vehicular hazard.

Head lamps. Lamps used to provide general illumination ahead of a
motor vehicle.

Heater. Any device or assembly of devices or appliances used to heat
the interior of any motor vehicle. This includes a catalytic heater
which must meet the requirements of Sec. 177.834(1) of this title when
flammable liquid or gas is transported.

Heavy hauler trailer. A trailer with one or more of the following
characteristics:

(1) Its brake lines are designed to adapt to separation or extension
of the vehicle frame; or

(2) Its body consists only of a platform whose primary cargo-
carrying surface is not more than 40 inches above the ground in an
unloaded condition, except that it may include sides that are designed
to be easily removable and a permanent ``front-end structure'' as that
term is used in Section 393.106 of this title.

Hook-lift container. A specialized container, primarily used to
contain and transport materials in the waste, recycling, construction/
demolition and scrap industries, which is used in conjunction with
specialized vehicles, in which the container is loaded and unloaded onto
a tilt frame body by an articulating hook-arm.

Identification lamps. Lamps used to identify certain types of
commercial motor vehicles.

Integral securement system. A system on certain roll-on/roll-off
containers and hook-lift containers and their related transport vehicles
in which compatible front and rear hold down devices are mated to
provide securement of the complete vehicle and its articles of cargo.

Lamp. A device used to produce artificial light.

Length of a manufactured home. The largest exterior length in the
traveling mode, including any projections which contain interior space.
Length does not include bay windows, roof projections, overhangs, or
eaves under which there is no interior space, nor does it include
drawbars, couplings or hitches.

License plate lamp. A lamp used to illuminate the license plate on
the rear of a motor vehicle.

Longwood. All logs that are not shortwood, i.e., are over 4.9 m (16
feet) long. Such logs are usually described as long logs or treelength.

Low chassis vehicle. (1) A trailer or semitrailer manufactured on or
after January 26, 1998, having a chassis which extends behind the
rearmost point of the rearmost tires and which has a lower rear surface
that meets the guard width, height, and rear surface requirements of
Sec. 571.224 in effect on the date of manufacture, or a subsequent
edition.

(2) A motor vehicle, not described by paragraph (1) of this
definition, having a chassis which extends behind the rearmost point of
the rearmost tires and which has a lower rear surface that meets the
guard configuration requirements of Sec. 393.86(b)(1).

Manufactured home means a structure, transportable in one or more
sections, which in the traveling mode, is eight body feet or more in
width or forty body feet or more in length, or, when erected on site, is
three hundred twenty or more square feet, and which is built on a
permanent chassis and designed to be used as a dwelling with or without
a permanent foundation when connected to the required utilities, and
includes the plumbing, heating, air-conditioning, and electrical systems
contained therein. Calculations used to determine the number of square
feet in a structure will be based on the structure's exterior dimensions
measured at the largest horizontal projections when erected on site.
These dimensions will include all expandable rooms, cabinets, and other projections containing interior space, but do not include bay
windows. This term includes all structures which meet the above
requirements except the size requirements and with respect to which the
manufacturer voluntarily files a certification pursuant to 24 CFR
3282.13 and complies with the standards set forth in 24 CFR part 3280.

Parking brake system. A brake system used to hold a vehicle
stationary.

Play. Any free movement of components.

Pulpwood trailer. A trailer or semitrailer that is designed
exclusively for harvesting logs or pulpwood and constructed with a
skeletal frame with no means for attachment of a solid bed, body, or
container.

Rail vehicle. A vehicle whose skeletal structure is fitted with
stakes at the front and rear to contain logs loaded crosswise.
Rear extremity. The rearmost point on a motor vehicle that falls
above a horizontal plane located 560 mm (22 inches) above the ground and
below a horizontal plane located 1,900 mm (75 inches) above the ground
when the motor vehicle is stopped on level ground; unloaded; its fuel
tanks are full; the tires (and air suspension, if so equipped) are
inflated in accordance with the manufacturer's recommendations; and the
motor vehicle's cargo doors, tailgate, or other permanent structures are
positioned as they normally are when the vehicle is in motion.
Nonstructural protrusions such as taillamps, rubber bumpers, hinges and
latches are excluded from the determination of the rearmost point.

Reflective material. A material conforming to Federal Specification
L-S-300, ``Sheeting and Tape, Reflective; Non-exposed Lens, Adhesive
Backing,'' (September 7, 1965) meeting the performance standard in
either Table 1 or Table 1A of SAE Standard J594f, ``Reflex Reflectors''
(January, 1977).

Reflex reflector. A device which is used on a vehicle to give an
indication to an approaching driver by reflected lighted from the lamps
on the approaching vehicle.

Saddle-mount. A device, designed and constructed as to be readily
demountable, used in driveaway-towaway operations to perform the
functions of a conventional fifth wheel:

(1) Upper-half. Upper-half of a ``saddle-mount'' means that part of
the device which is securely attached to the towed vehicle and maintains
a fixed position relative thereto, but does not include the ``king-
pin;''

(2) Lower-half. Lower-half of a ``saddle-mount'' means that part of
the device which is securely attached to the towing vehicle and
maintains a fixed position relative thereto but does not include the
``king-pin;'' and

(3) King-pin. King-pin means that device which is used to connect
the ``upper-half'' to the ``lower-half'' in such manner as to permit
relative movement in a horizontal plane between the towed and towing
vehicles.

Service brake system. A primary brake system used for slowing and
stopping a vehicle.

Shoring bar. A device placed transversely between the walls of a
vehicle and cargo to prevent cargo from tipping or shifting.

Shortwood. All logs typically up to 4.9 m (16 feet) long. Such logs
are often described as cut-up logs, cut-to-length logs, bolts or
pulpwood. Shortwood may be loaded lengthwise or crosswise, though that
loaded crosswise is usually no more than 2.6 m (102 inches) long.

Sided vehicle. A vehicle whose cargo compartment is enclosed on all
four sides by walls of sufficient strength to contain articles of cargo,
where the walls may include latched openings for loading and unloading,
and includes vans, dump bodies, and a sided intermodal container carried
by a vehicle.

Side extremity. The outermost point on a side of the motor vehicle
that is above a horizontal plane located 560 mm (22 inches) above the
ground, below a horizontal plane located 1,900 mm (75 inches) above the
ground, and between a transverse vertical plane tangent to the rear
extremity of the vehicle and a transverse vertical plane located 305 mm
(12 inches) forward of that plane when the vehicle is unloaded; its fuel
tanks are full; and the tires (and air suspension, if so equipped) are
inflated in accordance with the manufacturer's recommendations. Non-
structural protrusions such as taillights, hinges and latches are excluded from the determination of the outermost point.

Side marker lamp (Intermediate). A lamp shown to the side of a
trailer to indicate the approximate middle of a trailer 30 feet or more
in length.

Side marker lamps. Lamps used on each side of a trailer to indicate
its overall length.

Special purpose vehicle. (1) A trailer or semitrailer manufactured
on or after January 26, 1998, having work-performing equipment that,
while the motor vehicle is in transit, resides in or moves through the
area that could be occupied by the horizontal member of the rear impact
guard, as defined by the guard width, height and rear surface
requirements of Sec. 571.224 (paragraphs S5.1.1 through S5.1.3), in
effect on the date of manufacture, or a subsequent edition.

(2) A motor vehicle, not described by paragraph (1) of this
definition, having work-performing equipment that, while the motor
vehicle is in transit, resides in or moves through the area that could
be occupied by the horizontal member of the rear impact guard, as
defined by the guard width, height and rear surface requirements of
Sec. 393.86(b)(1).

Steering wheel lash. The condition in which the steering wheel may
be turned through some part of a revolution without associated movement
of the front wheels.

Stop lamps. Lamps shown to the rear of a motor vehicle to indicate
that the service brake system is engaged.

Tail lamps. Lamps used to designate the rear of a motor vehicle.

Tiedown. A combination of securing devices which forms an assembly
that attaches articles of cargo to, or restrains articles of cargo on, a
vehicle or trailer, and is attached to anchor point(s).

Tractor-pole trailer. A combination vehicle that carries logs
lengthwise so that they form the body of the vehicle. The logs are
supported by a bunk located on the rear of the tractor, and another bunk
on the skeletal trailer. The tractor bunk may rotate about a vertical
axis, and the trailer may have a fixed, scoping, or cabled reach, or
other mechanical freedom, to allow it to turn.

Turn signals. Lamps used to indicate a change in direction by
emitting a flashing light on the side of a motor vehicle towards which a
turn will be made.

Upper coupler assembly. A structure consisting of an upper coupler
plate, king-pin and supporting framework which interfaces with and
couples to a fifth wheel.

Upper coupler plate. A plate structure through which the king-pin
neck and collar extend. The bottom surface of the plate contacts the
fifth wheel when coupled.

Void filler. Material used to fill a space between articles of cargo
and the structure of the vehicle that has sufficient strength to prevent
movement of the articles of cargo.

Well. The depression formed between two cylindrical articles of
cargo when they are laid with their eyes horizontal and parallel against
each other.

Wheels back vehicle. (1) A trailer or semitrailer manufactured on or
after January 26, 1998, whose rearmost axle is permanently fixed and is
located such that the rearmost surface of the tires (of the size
recommended by the vehicle manufacturer for the rear axle) is not more
than 305 mm (12 inches) forward of the transverse vertical plane tangent
to the rear extremity of the vehicle.

(2) A motor vehicle, not described by paragraph (1) of this
definition, whose rearmost axle is permanently fixed and is located such
that the rearmost surface of the tires (of the size recommended by the
vehicle manufacturer for the rear axle) is not more than 610 mm (24
inches) forward of the transverse vertical plane tangent to the rear
extremity of the vehicle.

Width of a manufactured home. The largest exterior width in the
traveling mode, including any projections which contain interior space.
Width does not include bay windows, roof projections, overhangs, or
eaves under which there is no interior space.

Working load limit (WLL). The maximum load that may be applied to a 
component of a cargo securement system during normal service, usually
assigned by the manufacturer of the component.

Sec. 393.7 Matter incorporated by reference.

(a) Incorporation by reference. Part 393 includes references to
certain matter or materials, as listed in paragraph (b) of this section.
The text of the materials is not included in the regulations contained
in part 393. The materials are hereby made a part of the regulations in
part 393. The Director of the Federal Register has approved the
materials incorporated by reference in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. For materials subject to change, only the specific
version approved by the Director of the Federal Register and specified
in the regulation are incorporated. Material is incorporated as it
exists on the date of the approval and a notice of any change in these
materials will be published in the Federal Register.

(b) Matter or materials referenced in part 393. The matter or
materials listed in this paragraph are incorporated by reference in the
corresponding sections noted.

(1) Highway Emergency Signals, Fourth Edition, Underwriters
Laboratories, Inc., UL No. 912, July 30, 1979, (with an amendment dated
November 9, 1981), incorporation by reference approved for
Sec. 393.95(j).

(2) Standard Specification for Strapping, Flat Steel and Seals,
American Society for Testing and Materials (ASTM), D3953-97, February
1998, incorporation by reference approved for Sec. 393.104(e).

(3) Welded Steel Chain Specifications, National Association of Chain
Manufacturers, November 15, 1999, incorporation by reference approved
for Sec. 393.104(e).

(4) Recommended Standard Specification for Synthetic Web Tiedowns,
Web Sling and Tiedown Association, WSTDA-T1, 1998, incorporation by
reference approved for Sec. 393.104(e).

(5) Wire Rope Users Manual, 2nd Edition, Wire Rope Technical Board
November 1985, incorporation by reference approved for Sec. 393.104(e).

(6) Cordage Institute rope standards approved for incorporation into
Sec. 393.104(e):

(i) PETRS-2, Polyester Fiber Rope, 3-Strand and 8-Strand
Constructions, January 1993;

(ii) PPRS-2, Polypropylene Fiber Rope, 3-Strand and 8-Strand
Constructions, August 1992;

(iii) CRS-1, Polyester/Polypropylene Composite Rope Specifications,
Three-Strand and Eight-Strand Standard Construction, May 1979;

(iv) NRS-1, Nylon Rope Specifications, Three-Strand and Eight-Strand
Standard Construction, May 1979; and

(v) C-1, Double Braided Nylon Rope Specifications DBN, January 1984.

(c) Availability. The materials incorporated by reference are
available as follows:

(1) Standards of the Underwriters Laboratories, Inc. Information and
copies may be obtained by writing to: Underwriters Laboratories, Inc.,
333 Pfingsten Road, Northbrook, Illinois 60062.

(2) Specifications of the American Society for Testing and
Materials. Information and copies may be obtained by writing to:
American Society for Testing and Materials, 100 Barr Harbor Drive, West
Conshohocken, Pennsylvania 19428-2959.

(3) Specifications of the National Association of Chain
Manufacturers. Information and copies may be obtained by writing to:
National Association of Chain Manufacturers, P.O. Box 22681, Lehigh
Valley, Pennsylvania 18002-2681.

(4) Specifications of the Web Sling and Tiedown Association.
Information and copies may be obtained by writing to: Web Sling and
Tiedown Association, Inc., 5024-R Campbell Boulevard, Baltimore,
Maryland 21236-5974.

(5) Manuals of the Wire Rope Technical Board. Information and copies
may be obtained by writing to: Wire Rope Technical Committee, P.O. Box
849, Stevensville, Maryland 21666.

(6) Standards of the Cordage Institute. Information and copies may
be obtained by writing to: Cordage Institute, 350 Lincoln Street,
115, Hingham, Massachusetts 02043.

(7)-(9) [Reserved].

(10) All of the materials incorporated by reference are available
for inspection at:

(i) The Federal Motor Carrier Safety Administration, Office of Bus
and Truck Standards and Operations, 400 Seventh Street, SW., Washington,
DC 20590; and

(ii) The Office of the Federal Register, 800 North Capitol Street,
NW, Suite 700, Washington, DC.

Sec. 393.9 Lamps operable.

All lamps required by this subpart shall be capable of being
operated at all times.

Sec. 393.11 Lighting devices and reflectors.

The following Table 1 sets forth the required color, position, and
required lighting devices by type of commercial motor vehicle. Diagrams
illustrating the locations of lighting devices and reflectors, by type
and size of commercial motor vehicle, are shown immediately following
Table 1. All lighting devices on motor vehicles placed in operation
after March 7, 1989, must meet the requirements of 49 CFR 571.108 in
effect at the time of manufacture of the vehicle. Motor vehicles placed
in operation on or before March 7, 1989, must meet either the
requirements of this subchapter or part 571 of this title in effect at
the time of manufacture.

Sec. 393.13 Retroreflective sheeting and reflex reflectors, requirements for semitrailers and trailers manufactured before December 1, 1993.

(a) Applicability. All trailers and semitrailers manufactured prior
to December 1, 1993, which have an overall width of 2,032 mm (80 inches)
or more and a gross vehicle weight rating of 4,536 kg (10,001 pounds) or
more, except trailers that are manufactured exclusively for use as
offices or dwellings, pole trailers (as defined in Sec. 390.5 of this
subchapter), and trailers transported in a driveaway-towaway operation,
must be equipped with retroreflective sheeting or an array of reflex
reflectors that meet the requirements of this section. Motor carriers
operating trailers, other than container chassis (as defined in Sec. 393.5), 
have until June 1, 2001, to comply with the requirements of
this section. Motor carriers operating container chassis have until
December 1, 2001, to comply with the requirements of this section.

(b) Retroreflective sheeting and reflex reflectors. Motor carriers
are encouraged to retrofit their trailers with a conspicuity system that
meets all of the requirements applicable to trailers manufactured on or
after December 1, 1993, including the use of retroreflective sheeting or
reflex reflectors in a red and white pattern (see Federal Motor Vehicle
Safety Standard No. 108 (49 CFR 571.108), S5.7, Conspicuity systems).
Motor carriers which do not retrofit their trailers to meet the
requirements of FMVSS No. 108, for example by using an alternative color
pattern, must comply with the remainder of this paragraph and with
paragraph (c) or (d) of this section. Retroreflective sheeting or reflex
reflectors in colors or color combinations other than red and white may
be used on the sides or lower rear area of the semitrailer or trailer
until June 1, 2009. The alternate color or color combination must be
uniform along the sides and lower rear area of the trailer. The
retroreflective sheeting or reflex reflectors on the upper rear area of
the trailer must be white and conform to the requirements of FMVSS No.
108 (S5.7). Red retroreflective sheeting or reflex reflectors shall not
be used along the sides of the trailer unless it is used as part of a
red and white pattern. Retroreflective sheeting shall have a width of at
least 50 mm (2 inches).

(c) Locations for retroreflective sheeting--

(1) Sides. Retroreflective sheeting shall be applied to each side of the trailer or
semitrailer. Each strip of retroreflective sheeting shall be positioned
as horizontally as practicable, beginning and ending as close to the
front and rear as practicable. The strip need not be continuous but the
sum of the length of all of the segments shall be at least half of the
length of the trailer and the spaces between the segments of the strip
shall be distributed as evenly as practicable. The centerline for each
strip of retroreflective sheeting shall be between 375 mm (15 inches)
and 1,525 mm (60 inches) above the road surface when measured with the
trailer empty or unladen, or as close as practicable to this area. If
necessary to clear rivet heads or other similar obstructions, 50 mm (2
inches) wide retroreflective sheeting may be separated into two 25 mm (1
inch) wide strips of the same length and color, separated by a space of
not more than 25 mm (1 inch).

(2) Lower rear area. The rear of each trailer and semitrailer must
be equipped with retroreflective sheeting. Each strip of retroreflective
sheeting shall be positioned as horizontally as practicable, extending
across the full width of the trailer, beginning and ending as close to
the extreme edges as practicable. The centerline for each of the strips
of retroreflective sheeting shall be between 375 mm (15 inches) and
1,525 mm (60 inches) above the road surface when measured with the
trailer empty or unladen, or as close as practicable to this area.

(3) Upper rear area. Two pairs of white strips of retroreflective
sheeting, each pair consisting of strips 300 mm (12 inches) long, must
be positioned horizontally and vertically on the right and left upper
corners of the rear of the body of each trailer and semitrailer, as
close as practicable to the top of the trailer and as far apart as
practicable. If the perimeter of the body, as viewed from the rear, is
not square or rectangular, the strips may be applied along the
perimeter, as close as practicable to the uppermost and outermost areas
of the rear of the body on the left and right sides.

(d) Locations for reflex reflectors.--

(1) Sides. Reflex reflectors shall be applied to each side of the 
trailer or semitrailer. Each array of reflex reflectors shall be positioned 
as horizontally as practicable,beginning and ending as close to the front 
and rear as practicable. The array need not be continuous but the sum 
of the length of all of the array segments shall be at least half of the 
length of the trailer and the spaces between the segments of the strip 
shall be distributed as evenly as practicable. The centerline for each array 
of reflexreflectors shall be between 375 mm (15 inches) and 1,525 mm 
(60 inches)above the road surface when measured with the trailer empty 
or unladen, or as close as practicable to this area. The center of each 
reflector shall not be more than 100 mm (4 inches) from the center 
of each adjacent reflector in the segment of the array. If reflex reflectors 
are arranged in an alternating color pattern, the length of reflectors of the 
first color shall be as closeas practicable to the length of the reflectors of 
the second color.

(2) Lower rear area. The rear of each trailer and semitrailer must
be equipped with reflex reflectors. Each array of reflex reflectors
shall be positioned as horizontally as practicable, extending across the
full width of the trailer, beginning and ending as close to the extreme
edges as practicable. The centerline for each array of reflex reflectors
shall be between 375 mm (15 inches) and 1,525 mm (60 inches) above the
road surface when measured with the trailer empty or unladen, or as
close as practicable to this area. The center of each reflector shall
not be more than 100 mm (4 inches) from the center of each adjacent
reflector in the segment of the array.

(3) Upper rear area. Two pairs of white reflex reflector arrays,
each pair at least 300 mm (12 inches) long, must be positioned
horizontally and vertically on the right and left upper corners of the
rear of the body of each trailer and semitrailer, as close as
practicable to the top of the trailer and as far apart as practicable.
If the perimeter of the body, as viewed from the rear, is not square or
rectangular, the arrays may be applied along the perimeter, as close as
practicable to the uppermost and outermost areas of the rear of the body
on the left and right sides. The center of each reflector shall not be
more than 100 mm (4 inches) from the center of each adjacent reflector
in the segment of the array.

Sec. 393.17 Lamps and reflectors--combinations in driveaway-towaway operation.

A combination of motor vehicles engaged in driveaway-towaway
operation must be equipped with operative lamps and reflectors
conforming to the rules in this section.

(a) The towing vehicle must be equipped as follows:

(1) On the front, there must be at least two headlamps, an equal
number at each side, two turn signals, one at each side, and two
clearance lamps, one at each side.

(2) On each side, there must be at least one side-marker lamp,
located near the front of the vehicle.

(3) On the rear, there must be at least two tail lamps, one at each
side, and two stop lamps, one at each side.

(b) Except as provided in paragraph (c) of this section, the
rearmost towed vehicle of the combination (including the towed vehicle
or a tow-bar combination, the towed vehicle of a single saddle-mount
combination, and the rearmost towed vehicle of a double or triple
saddle-mount combination) or, in the case of a vehicle full-mounted on a
saddle-mount vehicle, either the full-mounted vehicle or the rearmost
saddle-mounted vehicle must be equipped as follows:

(1) On each side, there must be at least one side-marker lamp,
located near the rear of the vehicle.

(2) On the rear, there must be at least two tail lamps, two stop
lamps, two turn signals, two clearance lamps, and two reflectors, one of
each type at each side. In addition, if any vehicle in the combination
is 80 inches or more in overall width, there must be three
identification lamps on the rear.

(c) If the towed vehicle in a combination is a mobile structure
trailer, it must be equipped in accordance with the following lighting
devices. For the purposes of this part, mobile structure trailer means a
trailer that has a roof and walls, is at least 10 feet wide, and can be
used off road for dwelling or commercial purposes.

(1) When the vehicle is operated in accordance with the terms of a
special permit prohibiting operation during the times when lighted lamps
are required under Sec. 392.30, it must have on the rear--

(i) Two stop lamps, one on each side of the vertical centerline, at
the same height, and as far apart as practicable;

(ii) Two tail lamps, one on each side of the vertical centerline, at
the same height, and as far apart as practicable;

(iii) Two red reflex reflectors, one on each side of the vertical
centerline, at the same height, and as far apart as practicable; and

(iv) Two turn signal lamps, one on each side of the vertical
centerline, at the same height, and as far apart as practicable.

(2) At all other times, the vehicle must be equipped as specified in
paragraph (b) of this section.

(d) An intermediate towed vehicle in a combination consisting of
more than two vehicles (including the first saddle-mounted vehicle of a
double saddle-mount combination and the first and second saddle-mount
vehicles of a triple saddle-mount combination) must have one side-marker
lamp on each side, located near the rear of the vehicle.

Sec. 393.19 Requirements for turn signaling systems.

(a) Every bus, truck, or truck tractor shall be equipped with a
signaling system that in addition to signaling turning movements shall
have a switch or combination of switches that will cause the two front
turn signals and the two rear turn signals to flash simultaneously as a
vehicular traffic hazard warning as required by Sec. 392.22 with the
ignition on or off.

(b) Every semitrailer and full trailer shall be equipped so as to
have the two rear turn signals to flash simultaneously with the two
front turn signals of the towing vehicle as a vehicular traffic hazard
warning as required by Sec. 392.22(a).

Sec. 393.20 Clearance lamps to indicate extreme width and height.

Clearance lamps shall be mounted so as to indicate the extreme width
of the motor vehicle (not including mirrors) and as near the top thereof
as practicable: Provided, That when rear identification lamps are
mounted at the extreme height of the vehicle, rear clearance lamps may
be mounted at optional height: And provided further, That when mounting
of front clearance lamps at the highest point of a trailer results in
such lamps failing to mark the extreme width of the trailer, such lamps
may be mounted at optional height but must indicate the extreme width of
the trailer. Clearance lamps on truck tractors shall be so located as to
indicate the extreme width of the truck tractor cab.

Sec. 393.22 Combination of lighting devices and reflectors.

(a) Permitted combinations. Except as provided in paragraph (b) of
this section, two or more lighting devices and reflectors (whether or
not required by the rules in this part) may be combined optically if--

(1) Each required lighting device and reflector conforms to the
applicable rules in this part; and

(2) Neither the mounting nor the use of a nonrequired lighting
device or reflector impairs the effectiveness of a required lighting
device or reflector or causes that device or reflector to be
inconsistent with the applicable rules in this part.

(b) Prohibited combinations. (1) A turn signal lamp must not be
combined optically with either a head lamp or other lighting device or
combination of lighting devices that produces a greater intensity of
light than the turn signal lamp.

(2) A turn signal lamp must not be combined optically with a stop
lamp unless the stop lamp function is always deactivated when the turn
signal function is activated.

(3) A clearance lamp must not be combined optically with a tail lamp
or identification lamp.

Sec. 393.23 Lighting devices to be electric.

Lighting devices shall be electric, except that red liquid-burning
lanterns may be used on the end of loads in the nature of poles, pipes,
and ladders projecting to the rear of the motor vehicle.

Sec. 393.24 Requirements for head lamps and auxiliary road lighting lamps.

(a) Mounting. Head lamps and auxiliary road lighting lamps shall be
mounted so that the beams are readily adjustable, both vertically and
horizontally, and the mounting shall be such that the aim is not readily
disturbed by ordinary conditions of service.

(b) Head lamps required. Every bus, truck, and truck tractor shall
be equipped with a headlighting system composed of at least two head
lamps, not including fog or other auxiliary lamps, with an equal number
on each side of the vehicle. The headlighting system shall provide an
upper and lower distribution of light, selectable at the driver's will.

(c) Fog, adverse-weather, and auxiliary road-lighting lamps. For the
purposes of this section, fog, adverse-weather, and auxiliary road
lighting lamps, when installed, are considered to be a part of the
headlighting system. Such lamps may be used in lieu of head lamps under
conditions making their use advisable if there be at least one such lamp
conforming to the appropriate SAE Standard \1\ for such lamps on each
side of the vehicle.
---------------------------------------------------------------------------

\1\ Wherever reference is made in these regulations to SAE Standards
or SAE Recommended Practices, they shall be:

(a) As found in the 1985 edition of the SAE Handbook with respect to
parts and accessories other than lighting devices and reflectors.

(b) When reference is made in these regulations to SAE Standards or
SAE Recommended Practices, they shall be as found in the 1985 edition of
the SAE Handbook:

(1) With respect to parts and accessories other than lighting
devices and reflectors:

(2) Lighting devices and reflectors on motor vehicles manufactured
on and after March 7, 1990, shall conform to FMVSS 571.108 (49 CFR
571.108) in effect at the time of manufacture of the vehicle. Should a
conflict arise between FMVSS 571.108 and a SAE Standard, FMVSS 571.108
will prevail.
---------------------------------------------------------------------------

(d) Aiming and intensity. Head lamps shall be constructed and
installed so as to provide adequate and reliable illumination and shall
conform to the appropriate specification set forth in the SAE Standards
\1\ for ``Electric Head Lamps for Motor Vehicles'' or ``Sealed-Beam Head
Lamp Units for Motor Vehicles.''

Sec. 393.25 Requirements for lamps other than head lamps.

(a) Mounting. All lamps shall be permanently and securely mounted in
workmanlike manner on a permanent part of the motor vehicle, except that
temporary lamps on motor vehicles being transported in driveaway-towaway
operations and temporary electric lamps on projecting loads need not be
permanently mounted nor mounted on a permanent part of the vehicle. The
requirement for three identification lamps on the centerline of a
vehicle will be met as to location by one lamp on the centerline, with
the other two at right and left. All temporary lamps must be firmly
attached.

(b) Visibility. All required exterior lamps shall be so mounted as
to be capable of being seen at all distances between 500 feet and 50
feet under clear atmospheric conditions during the time lamps are
required to be lighted. The light from front clearance and front
identification lamps shall be visible to the front, that from sidemarker
lamps to the side, that from rear clearance, rear identification, and
tail lamps to the rear, and that from projecting loadmarker lamps from
those directions required by Sec. 393.11. This shall not be construed to
apply to lamps on one unit which are obscured by another unit of a
combination of vehicles.

(c) Specifications. All required lamps except those already
installed on vehicles tendered for transportation in 
driveaway and towaway operations shall conform to appropriate
requirements of the SAE Standards and/or Recommended Practices \1\ as
indicated below, except that the minimum required marking of lamps
conforming to the 1985 requirements shall be as specified in paragraph
(d) of this section. Projecting load marker lamps shall conform to the
requirements for clearance, side-marker, and identification lamps. Turn
signals shall conform to the requirements for class A, Type I turn
signals, provided.
---------------------------------------------------------------------------

\1\ See footnote 1 to Sec. 393.24(c).
---------------------------------------------------------------------------

(1) Lamps on vehicles made before July 1, 1961, excepting
replacement lamps as specified in paragraph (c)(2) of this section,
shall conform to the 1952 requirements.

(2) Lamps on vehicles made on and after July 1, 1961, and
replacement lamps installed on and after December 31, 1961, shall
conform to the 1985 requirements.

(3) Lamps temporarily attached to vehicles transported in driveaway
and towaway operations on and after December 31, 1961, shall conform to
the 1985 requirements.

(d) Certification and markings. All lamps required to conform to the
requirements of the SAE Standards \1\ shall be certified by the
manufacturer or supplier that they do so conform, by markings indicated
below. The markings in each case shall be visible when the lamp is in
place on the vehicle.
---------------------------------------------------------------------------

\1\ See footnote 1 to Sec. 393.24(c).
---------------------------------------------------------------------------

(1) Stop lamps shall be marked with the manufacturer's or supplier's
name or trade name and shall be marked ``SAE-S''.

(2) Turn signal units shall be marked with the manufacturer's or
supplier's name or trade name and shall be marked ``SAE-AI'' or ``SAE-
I''.

(3) Tail lamps shall be marked with the manufacturer's or supplier's
name or trade name and shall be marked ``SAE-T''.

(4) Clearance, side marker, identification, and projecting load-
marker lamps, except combination lamps, shall be marked with the
manufacturer's or supplier's name or trade name and shall be marked
``SAE'' or ``SAE-P''.

(5) Combination lamps shall be marked with the manufacturer's or
supplier's name or trade name and shall be marked ``SAE'' followed by
the appropriate letters indicating the individual lamps combined. The
letter ``A'', as specified in Sec. 393.26(c), may be included to certify
that a reflector in the combination conforms to the requirements
appropriate to such marking. If the letter ``I'' follows the letter
``A'' immediately the two letters shall be deemed to refer to a turn
signal unit, as specified in paragraph (d)(2) of this section.
Combination clearance and side marker lamps may be marked ``SAE-PC''.

(e) Lighting devices to be steady-burning. All exterior lighting
devices shall be of the steady-burning type except turn signals on any
vehicle, stop lamps when used as turn signals, warning lamps on school
buses when operating as such, and warning lamps on emergency and service
vehicles authorized by State or local authorities, and except that lamps
combined into the same shell or housing with any turn signal may be
turned off by the same switch that turns the signal on for flashing and
turned on again when the turn signal as such is turned off. This
paragraph shall not be construed to prohibit the use of vehicular hazard
warning signal flashers as required by Sec. 392.22 or permitted by
Sec. 392.18.

(f) Stop lamp operation. All stop lamps on each motor vehicle or
combination of motor vehicles shall be actuated upon application of any
of the service brakes, except that such actuation is not required upon
activation of the emergency feature of trailer brakes by means of either
manual or automatic control on the towing vehicle, and except that stop
lamps on a towing vehicle need not be actuated when service brakes are
applied to the towed vehicles or vehicles only, and except that no stop
lamp need be actuated as such when it is in use as a turn signal or when
it is turned off by the turn signal switch as provided in paragraph (e)
of this section.

Sec. 393.26 Requirements for reflectors.

(a) Mounting. All required reflectors shall be mounted upon the
motor vehicle at a height not less than 15 inches nor more than 60
inches above the ground on which the motor vehicle stands, except that
reflectors shall be mounted as high as practicable on motor vehicles
which are so constructed as to make compliance with the 15-inch
requirement impractical. They shall be so installed as to perform their
function adequately and reliably, and except for temporary reflectors
required for vehicles in driveaway-towaway operations, or on projecting
loads, all reflectors shall be permanently and securely mounted in
workmanlike manner so as to provide the maximum of stability and the
minimum likelihood of damage. Required reflectors otherwise properly
mounted may be securely installed on flexible strapping or belting
provided that under conditions of normal operation they reflect light in
the required directions. Required temporary reflectors mounted on motor
vehicles during the time they are in transit in any driveaway-towaway
operation must be firmly attached.

(b) Specifications. All required reflectors except those installed
on vehicles tendered for transportation in driveaway and towaway
operations shall comply with FMVSS 571.108 (49 CFR 571.108) in effect at
the time the vehicle was manufactured or the current FMVSS 571.108
requirements.

(c) Certification and markings. All reflectors required to conform
to the specifications in paragraph (b) shall be certified by the
manufacturer or supplier that they do so conform, by marking with the
manufacturer's or supplier's name or trade name and the letters ``SAE-
A''. The marking in each case shall be visible when the reflector is in
place on the vehicle.

(d) Retroreflective surfaces. Retroreflective surfaces other than
required reflectors may be used, provided:

(1) Designs do not resemble traffic control signs, lights, or
devices, except that straight edge striping resembling a barricade
pattern may be used.

(2) Designs do not tend to distort the length and/or width of the
motor vehicle.

(3) Such surfaces shall be at least 3 inches from any required lamp
or reflector unless of the same color as such lamp or reflector.

(4) No red color shall be used on the front of any motor vehicle,
except for display of markings or placards required by Sec. 177.823 of
this title.

(5) Retroreflective license plates required by State or local
authorities may be used.

Sec. 393.27 Wiring specifications.

(a) Wiring for both low voltage (tension) and high voltage (tension)
circuits shall be constructed and installed so as to meet design
requirements. Wiring shall meet or exceed, both mechanically and
electrically, the following SAE Standards as found in the 1985 edition
of the SAE Handbook:

(1) Commercial vehicle engine ignition systems-SAE J557-High Tension
Ignition Cable.

(2) Commercial vehicle battery cable-SAE J1127-Jan 80-Battery Cable.

(3) Other commercial vehicle wiring-SAE J1128-Low Tension Primary
Cable.

(b) The source of power and the electrical wiring shall be of such
size and characteristics as to provide the necessary voltage as the
design requires to comply with FMVSS 571.108.

(c) Lamps shall be properly grounded.

Sec. 393.28 Wiring to be protected.

(a) The wiring shall--

(1) Be so installed that connections are protected from weather,
abrasion, road splash, grease, oil, fuel and chafing;

(2) Be grouped together, when possible, and protected by
nonconductive tape, braid, or other covering capable of withstanding
severe abrasion or shall be protected by being enclosed in a sheath or
tube;

(3) Be properly supported in a manner to prevent chafing;

(4) Not be so located as to be likely to be charred, overheated, or
enmeshed in moving parts;

(5) Not have terminals or splices located above the fuel tank except
for the fuel sender wiring and terminal; and

(6) Be protected when passing through holes in metal by a grommet,
or other means, or the wiring shall be encased in a protective covering.

(b) The complete wiring system including lamps, junction boxes,
receptacle boxes, conduit and fittings must be weather resistant.

(c) Harness connections shall be accomplished by a mechanical means.

Sec. 393.29 Grounds.

The battery ground and trailer return ground connections on a
grounded system shall be readily accessible. The contact surfaces of
electrical connections shall be clean and free of oxide, paint, or other
nonconductive coating.

Sec. 393.30 Battery installation.

Every storage battery on every vehicle, unless located in the engine
compartment, shall be covered by a fixed part of the motor vehicle or
protected by a removable cover or enclosure. Removable covers or
enclosures shall be substantial and shall be securely latched or
fastened. The storage battery compartment and adjacent metal parts which
might corrode by reason of battery leakage shall be painted or coated
with an acid-resisting paint or coating and shall have openings to
provide ample battery ventilation and drainage. Wherever the cable to
the starting motor passes through a metal compartment, the cable shall
be protected against grounding by an acid and waterproof insulating
bushing. Wherever a battery and a fuel tank are both placed under the
driver's seat, they shall be partitioned from each other, and each
compartment shall be provided with an independent cover, ventilation,
and drainage.

Sec. 393.31 Overload protective devices.

(a) The current to all low tension circuits shall pass through
overload protective devices except that this requirement shall not be
applicable to battery-to-starting motor or battery-to-generator
circuits, ignition and engine control circuits, horn circuits,
electrically-operated fuel pump circuits, or electric brake circuits.

(b) Trucks, truck-tractors, and buses meeting the definition of a
commercial motor vehicle and manufactured after June 30, 1953 shall have
protective devices for electrical circuits arranged so that:

(1) The headlamp circuit or circuits shall not be affected by a
short circuit in any other lighting circuits on the motor vehicle; or

(2) The protective device shall be an automatic reset overload
circuit breaker if the headlight circuit is protected in common with
other circuits.

Sec. 393.32 Detachable electrical connections.

Electrical wiring between towing and towed vehicles shall be
contained in a cable or cables or entirely within another substantially
constructed protective device. All such electrical wiring shall be
mechanically and electrically adequate and free of short or open
circuits. Suitable provision shall be made in every such detachable
connection to afford reasonable assurance against connection in an
incorrect manner or accidental disconnection. Detachable connections
made by twisting together wires from the towed and towing units are
prohibited. Precaution shall be taken to provide sufficient slack in the
connecting wire or cable to accommodate without damage all normal
motions of the parts to which they are attached.

Sec. 393.33 Wiring, installation.

Electrical wiring shall be systematically arranged and installed in
a workmanlike manner. All detachable wiring, except temporary wiring
connections for driveaway-towaway operations, shall be attached to posts
or terminals by means of suitable cable terminals which conform to the 
SAE Standard \1\ for ``Cable Terminals'' or by cable terminals which are 
mechanically and electrically at least equal to such terminals. The number 
of wires attached to any post shallbe limited to the number which such post 
was designed to accommodate. The presence of bare, loose, dangling, 
chafing, or poorly connected wires is prohibited.

Sec. 393.40 Required brake systems.

(a) General. A bus, truck, truck tractor, or a combination of motor
vehicles must have brakes adequate to control the movement of, and to
stop and hold, the vehicle or combination of vehicles.

(b) Specific systems required. (1) A bus, truck, truck tractor, or
combination of motor vehicles must have--

(i) A service brake system that conforms to the requirements of
Sec. 393.52; and

(ii) A parking brake system that conforms to the requirements of
Sec. 393.41.

(2) A bus, truck, truck tractor, or a combination of motor vehicles
manufactured on or after July 1, 1973, must have an emergency brake
system that conforms to the requirements of Sec. 393.52(b) and consists
of either--

(i) Emergency features of the service brake system; or

(ii) A system separate from the service brake system.

A control by which the driver applies the emergency brake system must be
located so that the driver can readily operate it when he/she is
properly restrained by any seat belt assembly provided for his/her use.
The control for applying the emergency brake system may be combined with
either the control for applying the service brake system or the control
for applying the parking brake system. However, all three controls may
not be combined.

(c) Interconnected systems. (1) If the brake systems specified in
paragraph (b) of this section are interconnected in any way, they must
be designed, constructed, and maintained so that, upon the failure of
any part of the operating mechanism of one or more of the systems
(except the service brake actuation pedal or valve)--

(i) The vehicle will have operative brakes; and

(ii) In the case of a vehicle manufactured on or after July 1, 1973,
the vehicle will have operative brakes capable of performing as
specified in Sec. 393.52(b).

(2) A motor vehicle to which the emergency brake system requirements
of Federal Motor Vehicle Safety Standard No. 105 (Sec. 571.105 of this
title) applied at the time of its manufacture conforms to the
requirements of paragraph (c)(1) of this section if--

(i) It is maintained in conformity with the emergency brake
requirements of Standard No. 105 in effect on the date of its
manufacture; and

(ii) It is capable of performing as specified in Sec. 393.52(b),
except upon structural failure of its brake master cylinder body or
effectiveness indicator body.

(3) A bus conforms to the requirements of paragraph (c)(1) of this
section if it meets the requirements of Sec. 393.44 and is capable of
performing as specified in Sec. 393.52(b).

Sec. 393.41 Parking brake system.

(a) Every commercial motor vehicle manufactured on and after March
7, 1990, except an agricultural commodity trailer, converter dolly,
heavy hauler or pulpwood trailer, shall at all times be equipped with a
parking brake system adequate to hold the vehicle or combination under
any condition of loading as required by FMVSS 571.121. An agricultural
commodity trailer, heavy hauler or pulpwood trailer shall carry
sufficient chocking blocks to prevent movement when parked.

(b) The parking brake system shall at all times be capable of being
applied in conformance with the requirements of paragraph (a) of the
section by either the driver's muscular effort, or by spring action, or
by other energy, provided, that if such other energy is depended on for
application of the parking brake, then an accumulation of such energy
shall be isolated from any common source and used exclusively for the
operation of the parking brake.

(c) The parking brake system shall be held in the applied position
by energy other than fluid pressure, air pressure, or electric energy.
The parking brake system shall be such that it cannot be released unless
adequate energy is available upon release of the parking brake to make
immediate further application with the required effectiveness.

Sec. 393.42 Brakes required on all wheels.

(a) Every commercial motor vehicle shall be equipped with brakes
acting on all wheels.

(b) Exception. (1) Trucks or truck tractors having three or more
axles--

(i) Need not have brakes on the front wheels if the vehicle was
manufactured before July 25, 1980; or

(ii) Manufactured between July 24, 1980, and October 27, 1986, must
be retrofitted to meet the requirements of this section within one year
from February 26, 1987, if the brake components have been removed.

(2) Any motor vehicle being towed in a driveaway-towaway operation
must have operative brakes as may be necessary to ensure compliance with
the performance requirements of Sec. 393.52. This paragraph is not
applicable to any motor vehicle towed by means of a tow-bar when any
other vehicle is full-mounted on such towed motor vehicle or any
combination of motor vehicles utilizing three or more saddle-mounts.
(See Sec. 393.71(a)(3).)

(3) Any full trailer, any semitrailer, or any pole trailer having a
GVWR of 3,000 pounds or less must be equipped with brakes if the weight
of the towed vehicle resting on the towing vehicle exceeds 40 percent of
the GVWR of the towing vehicle.

Sec. 393.43 Breakaway and emergency braking.

(a) Every motor vehicle, if used to tow a trailer equipped with
brakes, shall be equipped with means for providing that in case of
breakaway of such trailer the service brakes on the towing vehicle will
be sufficiently operative to stop the towing vehicle.

(b) Every truck or truck tractor equipped with air brakes, when used
for towing other vehicles equipped with air brakes, shall be equipped
with two means of activating the emergency features of the trailer
brakes. One of these means shall operate automatically in the event of
reduction of the towing vehicle air supply to a fixed pressure which
shall not be lower than 20 pounds per square inch nor higher than 45
pounds per square inch. The other means shall be a manually controlled
device readily operable by a person seated in the driving seat. Its
emergency position or method of operation shall be clearly indicated. In
no instance may the manual means be so arranged as to permit its use to
prevent operation of the automatic means. The automatic and manual means
required by this section may be, but are not required to be, separate.

(c) Every truck tractor and truck when used for towing other
vehicles equipped with vacuum brakes, shall have, in addition to the
single control required by Sec. 393.49 to operate all brakes of the
combination, a second manual control device which can be used
to operate the brakes on the towed vehicles in emergencies. Such 
second control shall be independent of brake air, hydraulic, and other 
pressure, and independent of other controls, unless the braking system 
be so arranged that failure of the pressure on which the second control 
depends will cause the towed vehicle brakes to be applied automatically. 
The second control is not required by this rule to provide modulated or 
graduated braking.

(d) Every trailer required to be equipped with brakes shall be
equipped with brakes of such character as to be applied automatically
and promptly upon breakaway from the towing vehicle, and means shall be
provided to maintain application of the brakes on the trailer in such
case for at least 15 minutes.

(e) Air brake systems installed on towed vehicles shall be so
designed, by the use of ``no-bleed-back'' relay emergency valves or
equivalent devices, that the supply reservoir used to provide air for
brakes shall be safeguarded against backflow of air to the towing
vehicle upon reduction of the towing vehicle air pressure.

(f) The requirements of paragraphs (b), (c), and (d) of this section
shall not be applicable to motor vehicles in driveaway-towaway
operations.

Sec. 393.44 Front brake lines, protection.

On every bus, if equipped with air brakes, the braking system shall
be so constructed that in the event any brake line to any of the front
wheels is broken, the driver can apply the brakes on the rear wheels
despite such breakage. The means used to apply the brakes may be located
forward of the driver's seat as long as it can be operated manually by
the driver when the driver is properly restrained by any seat belt
assembly provided for use. Every bus shall meet this requirement or
comply with the regulations in effect at the time of its manufacture.

Sec. 393.45 Brake tubing and hose, adequacy.

(a) General requirements. Brake tubing and brake hose must--

(1) Be designed and constructed in a manner that insures proper,
adequate, and continued functioning of the tubing or hose;

(2) Be installed in a manner that insures proper continued
functioning of the tubing or hose;

(3) Be long and flexible enough to accommodate without damage all
normal motions of the parts to which it is attached;

(4) Be suitably secured against chafing, kinking, or other
mechanical damage;

(5) Be installed in a manner that prevents it from contacting the
vehicle's exhaust system or any other source of high temperatures; and

(6) Conform to the applicable requirements of paragraph (b) or (c)
of this section. In addition, all hose installed on and after January 1,
1981, must conform to those applicable subsections of FMVSS 106 (49 CFR
571.106).

(b) Special requirements for metallic brake tubing, nonmetallic
brake tubing, coiled nonmetallic brake tubing and brake hose. (1)
Metallic brake tubing, nonmetallic brake tubing, coiled nonmetallic
brake tubing, and brake hose installed on a commercial motor vehicle on
and after March 7, 1989, must meet or exceed one of the following
specifications set forth in the SAE Handbook, 1985 edition:

(i) Metallic Air Brake Tubing--SAE Recommended Practice J1149--
Metallic Air Brake System Tubing and Pipe--July 76.

(ii) Nonmetallic Air Brake Tubing--SAE Recommended Practice J844--
Nonmetallic Air Brake System Type B--OCT 80.

(iii) Air Brake Hose--SAE Recommended Practice J1402--Automotive Air
Brake Hose and Hose Assemblies--JUN 85.

(iv) Hydraulic Brake Hose--SAE Recommended Practice J1401 Road
Vehicle-Hydraulic Brake Hose Assemblies for Use with Non-Petroleum Base
Hydraulic Fluid JUN 85.

(v) Vacuum Brake Hose--SAE Recommended Practice J1403 Vacuum Brake
Hose JUN 85.

(2) Except as provided in paragraph (c) of this section, brake hose
and brake tubing installed on a motor vehicle before March 7, 1989, must
conform to 49 CFR 393.45 effective October 31, 1983.

(c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may be
used for connections between towed and towing vehicles or between the
frame of a towed vehicle and the unsprung subframe of an adjustable axle
of that vehicle if--

(1) The coiled tubing has a straight segment (pigtail) at each end
that is at least 2 inches in length and is encased in a spring guard or
similar device which prevents the tubing from kinking at the fitting at
which it is attached to the vehicle; and

(2) The spring guard or similar device has at least 2 inches of
closed coils or similar surface at its interface with the fitting and
extends at least 1\1/2\ inches into the coiled segment of the tubing
from its straight segment.

(d) Brake tubing and brake hose, uses. Metallic and nonmetallic
brake tubing is intended for use in areas of the brake system where
relative movement in the line is not anticipated. Brake hose and coiled
nonmetallic brake tubing is intended for use in the brake system where
substantial relative movement in the line is anticipated or the hose/
coiled nonmetallic brake tubing is exposed to potential tension or
impact such as between the frame and axle in a conventional type
suspension system (axle attached to frame by suspension system).
Nonmetallic brake tubing may be used through an articulation point
provided movement is less than 4.5 degrees in a vertical plane, and 7.4
degrees in a transverse horizontal plane.

Sec. 393.46 Brake tubing and hose connections.

All connections for air, vacuum, or hydraulic braking systems shall:

(a) Be adequate in material and construction to insure proper
continued functioning;

(b) Be designed, constructed, and installed so as to insure, when
properly connected, an attachment free of leaks, constrictions, or other
defects;

(c) Have suitable provision in every detachable connection to afford
reasonable assurance against accidental disconnection;

(d) Have the vacuum brake engine manifold connection at least three-
eighths inch in diameter.

(e) If installed on a vehicle on or after January 1, 1981, meet
requirements under applicable subsections of FMVSS 106 (49 CFR 571.106).

(f) Splices in tubing if installed on a vehicle after March 7, 1989,
must use fittings that meet the requirements of SAE Standard J512-OCT 80
Automotive Tube Fittings or for air brake systems SAE J246--March 81
Spherical and Flanged Sleeve (Compression) Tube Fittings as found in the
SAE Handbook 1985 edition.

Sec. 393.47 Brake lining.

The brake lining in every motor vehicle shall be so constructed and
installed as not to be subject to excessive fading and grabbing and
shall be adequate in thickness, means of attachment, and physical
characteristics to provide for safe and reliable stopping of the motor
vehicle.

Sec. 393.48 Brakes to be operative.

(a) General rule. Except as provided in paragraphs (b) and (c) of
this section, all brakes with which a motor vehicle is equipped must at
all times be capable of operating.

(b) Devices to reduce or remove front-wheel braking effort. A motor
vehicle may be equipped with a device to reduce the braking effort upon
its front wheels or, in the case of a three-axle truck or truck tractor
manufactured before March 1, 1975, to remove the braking effort upon its
front wheels, if that device conforms to, and is used in compliance
with, the rules in paragraph (b) (1) or (2) of this section.

(1) Manually operated devices. A manually operated device to reduce
or remove the front-wheel braking effort must not be--

(i) Installed in a motor vehicle other than a bus, truck, or truck
tractor; or

(ii) Installed in a bus, truck, or truck tractor manufactured after
February 28, 1975; or

(iii) Used in the reduced mode except when the vehicle is operating
under adverse conditions such as wet, snowy, or icy roads.

(2) Automatic devices. An automatic device to reduce the front-wheel
braking effort by up to 50 percent of the normal braking force,
regardless of whether or not antilock system failure has occurred on any
axle, must not--

(i) Be operable by the driver except upon application of the control
that activates the braking system; and

(ii) Be operable when the pressure that transmits brake control
application force exceeds--

(A) 85 psig on air-mechanical braking systems; or

(B) 85 percent of the maximum system pressure in the case of
vehicles utilizing other than compressed air.

(c) Towed vehicle. Paragraph (a) of this section does not apply to--

(1) A disabled vehicle being towed; or

(2) A vehicle being towed in a driveaway-towaway operation which is
exempt from the general rule of Sec. 393.42 under paragraph (b) of that
section.

Sec. 393.49 Single valve to operate all brakes.

Every motor vehicle, the date of manufacture of which is subsequent
to June 30, 1953, which is equipped with power brakes, shall have the
braking system so arranged that one application valve shall when applied
operate all the service brakes on the motor vehicle or combination of
motor vehicles. This requirement shall not be construed to prohibit
motor vehicles from being equipped with an additional valve to be used
to operate the brakes on a trailer or trailers or as provided in
Sec. 393.44. This section shall not be applicable to driveaway-towaway
operations unless the brakes on such operations are designed to be
operated by a single valve.

Sec. 393.50 Reservoirs required.

(a) General. Every commercial motor vehicle using air or vacuum for
breaking shall be equipped with reserve capacity or a reservoir
sufficient to ensure a full service brake application with the engine
stopped without depleting the air pressure or vacuum below 70 percent of
that pressure or degree of vacuum indicated by the gauge immediately
before the brake application is made. For purposes of this section, a
full service brake application is considered to be made when the service
brake pedal is pushed to the limit of its travel.

(b) Safeguarding of air and vacuum. (1) Every bus, truck, and truck
tractor, when equipped with air or vacuum reservoirs and regardless of
date of manufacture, shall have such reservoirs so safeguarded by a
check valve or equivalent device that in the event of failure or leakage
in its connection to the source of compressed air or vacuum the air or
vacuum supply in the reservoir shall not be depleted by the leak or
failure.

(2) Means shall be provided to establish the check valve to be in
working order. On and after May 1, 1966, means other than loosening or
disconnection of any connection between the source of compressed air or
vacuum and the check valve, and necessary tools for operation of such
means, shall be provided to prove that the check valve is in working
order. The means shall be readily accessible either from the front,
side, or rear of the vehicle, or from the driver's compartment.

(i) In air brake systems with one reservoir, the means shall be a
cock, valve, plug, or equivalent device arranged to vent a cavity having
free communication with the connection between the check valve and the
source of compressed air or vacuum.

(ii) Where air is delivered by a compressor into one tank or
compartment (wet tank), and air for braking is taken directly from
another tank or compartment (dry tank) only, with the required check
valve between the tanks or compartments, a manually operated drain cock
on the first (wet) tank or compartment will serve as a means herein
required if it conforms to the requirements herein.

(iii) In vacuum systems stopping the engine will serve as the
required means, the system remaining evacuated as indicated 
by the vacuum gauge.

Sec. 393.51 Warning devices and gauges.

(a) General. In the manner and to the extent specified in paragraphs
(b), (c), (d), and (e) of this section, a bus, truck, or truck tractor
must be equipped with a signal that provides a warning to the driver
when a failure occurs in the vehicle's service brake system.

(b) Hydraulic brakes. A vehicle manufactured on or after July 1,
1973, and having service brakes activated by hydraulic fluid must be
equipped with a warning signal that performs as follows:

(1) If Federal Motor Vehicle Safety Standard No. 105 (Sec. 571.105
of this title) was applicable to the vehicle at the time it was
manufactured, the warning signal must conform to the requirements of
that standard.

(2) If Federal Motor Vehicle Safety Standard No. 105 (Sec. 571.105)
was not applicable to the vehicle at the time it was manufactured, the
warning signal must become operative, before or upon application of the
brakes in the event of a hydraulic-type complete failure of a partial
system. The signal must be readily audible or visible to the driver.

(c) Air brakes. A vehicle (regardless of the date it was
manufactured) having service brakes activated by compressed air (air-
mechanical brakes) or a vehicle towing a vehicle having service brakes
activated by compressed air (air-mechanical brakes) must be equipped,
and perform, as follows:

(1) The vehicle must have a low air pressure warning device that
conforms to the requirements of either paragraph (c)(1) (i) or (ii) of
this section.

(i) If Federal Motor Vehicle Safety Standard No. 121 (Sec. 571.121
of this title) was applicable to the vehicle at the time it was
manufactured, the warning device must conform to the requirements of
that standard.

(ii) If Federal Motor Vehicle Safety Standard No. 121 (Sec. 571.121)
was not applicable to the vehicle at the time it was manufactured, the
vehicle must have a device that provides a readily audible or visible
continuous warning to the driver whenever the pressure of the compressed
air in the braking system is below a specified pressure, which must be
at least one-half of the compressor governor cutout pressure.

(2) The vehicle must have a pressure gauge which indicates to the
driver the pressure in pounds per square inch available for braking.

(d) Vacuum brakes. A vehicle (regardless of the date it was
manufactured) having service brakes activated by vacuum or a vehicle
towing a vehicle having service brakes activated by vacuum must be
equipped with--

(1) A device that provides a readily audible or visible continuous
warning to the driver whenever the vacuum in the vehicle's supply
reservoir is less than 8 inches of mercury; and

(2) A vacuum gauge which indicates to the driver the vacuum in
inches of mercury available for braking.

(e) Hydraulic brakes applied or assisted by air or vacuum. A vehicle
having a braking system in which hydraulically activated service brakes
are applied or assisted by compressed air or vacuum must be equipped
with both a warning signal that conforms to the requirements of
paragraph (b) of this section and a warning device that conforms to the
requirements of either paragraph (c) or paragraph (d) of this section.

(f) Maintenance. The warning signals, devices, and gauges required
by this section must be maintained in operative condition.

Sec. 393.52 Brake performance.

(a) Upon application of its service brakes, a motor vehicle or
combination of motor vehicles must under any condition of loading in
which it is found on a public highway, be capable of--

(1) Developing a braking force at least equal to the percentage of
its gross weight specified in the table in paragraph (d) of this
section;

(2) Decelerating to a stop from 20 miles per hour at not less than
the rate specified in the table in paragraph (d) of this section; and

(3) Stopping from 20 miles per hour in a distance, measured from the
point at which movement of the service brake pedal or control begins,
that is not greater than the distance specified in the table in 
paragraph (d) of this section; or, for motor vehicles or
motor vehicle combinations that have a GVWR or GVW greater than 4,536 kg
(10,000 pounds),

(4) Developing only the braking force specified in paragraph (a)(1)
of this section and the stopping distance specified in paragraph (a)(3)
of this section, if braking force is measured by a performance-based
brake tester which meets the requirements of functional specifications
for performance-based brake testers for commercial motor vehicles, where
braking force is the sum of the braking force at each wheel of the
vehicle or vehicle combination as a percentage of gross vehicle or
combination weight.

(b) Upon application of its emergency brake system and with no other
brake system applied, a motor vehicle or combination of motor vehicles
must, under any condition of loading in which it is found on a public
highway, be capable of stopping from 20 miles per hour in a distance,
measured from the point at which movement of the emergency brake control
begins, that is not greater than the distance specified in the table in
paragraph (d) of this section.

(c) Conformity to the stopping-distance requirements of paragraphs
(a) and (b) of this section shall be determined under the following
conditions:

(1) Any test must be made with the vehicle on a hard surface that is
substantially level, dry, smooth, and free of loose material.

(2) The vehicle must be in the center of a 12-foot-wide lane when
the test begins and must not deviate from that lane during the test.

(d) Vehicle brake performance table:

Sec. 393.53 Automatic brake adjusters and brake adjustment indicators.

(a) Automatic brake adjusters (hydraulic brake systems). Each
commercial motor vehicle manufactured on or after October 20, 1993, and
equipped with a hydraulic brake system, shall meet the automatic brake
adjustment system requirements of Federal Motor Vehicle Safety Standard
No. 105 (49 CFR 571.105, S5.1) applicable to the vehicle at the time it
was manufactured.

(b) Automatic brake adjusters (air brake systems). Each commercial
motor vehicle manufactured on or after October 20, 1994, and equipped
with an air brake system shall meet the automatic brake adjustment
system requirements of Federal Motor Vehicle Safety Standard No. 121 (49
CFR 571.121, S5.1.8) applicable to the vehicle at the time it was
manufactured.

(c) Brake adjustment indicator (air brake systems). On each
commercial motor vehicle manufactured on or after October 20, 1994, and
equipped with an air brake system which contains an external automatic
adjustment mechanism and an exposed pushrod, the condition of service
brake under-adjustment shall be displayed by a brake adjustment
indicator conforming to the requirements of Federal Motor Vehicle Safety
Standard No. 121 (49 CFR 571.121, S5.1.8) applicable to the vehicle at
the time it was manufactured.

Sec. 393.55 Antilock brake systems.

(a) Hydraulic brake systems. Each truck and bus manufactured on or
after March 1, 1999 (except trucks and buses engaged in driveaway-
towaway operations), and equipped with a hydraulic brake system, shall
be equipped with an antilock brake system that meets the requirements of
Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105,
S5.5).

(b) ABS malfunction indicators for hydraulic braked vehicles. Each
hydraulic braked vehicle subject to the requirements of paragraph (a) of
this section shall be equipped with an ABS malfunction indicator system
that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3).

(c) Air brake systems. (1) Each truck tractor manufactured on or
after March 1, 1997 (except truck tractors engaged in driveaway-towaway
operations), shall be equipped with an antilock brake system that meets
the requirements of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)).

(2) Each air braked commercial motor vehicle other than a truck
tractor, manufactured on or after March 1, 1998 (except commercial motor
vehicles engaged in driveaway-towaway operations), shall be equipped
with an antilock brake system that meets the requirements of FMVSS No.
121 (49 CFR 571.121, S5.1.6.1(a) for trucks and buses, S5.2.3 for
semitrailers, converter dollies and full trailers).

(d) ABS malfunction circuits and signals for air braked vehicles.
(1) Each truck tractor manufactured on or after March 1, 1997, and each
single-unit air braked vehicle manufactured on or after March 1, 1998,
subject to the requirements of paragraph (c) of this section, shall be
equipped with an electrical circuit that is capable of signaling a
malfunction that affects the generation or transmission of response or
control signals to the vehicle's antilock brake system (49 CFR 571.121,
S5.1.6.2(a)).

(2) Each truck tractor manufactured on or after March 1, 2001, and
each single-unit vehicle that is equipped to tow another air-braked
vehicle, subject to the requirements of paragraph (c) of this section,
shall be equipped with an electrical circuit that is capable of
transmitting a malfunction signal from the antilock brake system(s) on
the towed vehicle(s) to the trailer ABS malfunction lamp in the cab of
the towing vehicle, and shall have the means for connection of the
electrical circuit to the towed vehicle. The ABS malfunction circuit and
signal shall meet the requirements of FMVSS No. 121 (49 CFR 571.121,
S5.1.6.2(b)).

(3) Each semitrailer, trailer converter dolly, and full trailer
manufactured on or after March 1, 2001, and subject to the 
requirements of paragraph (c)(2) of this section, shall
be equipped with an electrical circuit that is capable of signaling a
malfunction in the trailer's antilock brake system, and shall have the
means for connection of this ABS malfunction circuit to the towing
vehicle. In addition, each trailer manufactured on or after March 1,
2001, subject to the requirements of paragraph (c)(2) of this section,
that is designed to tow another air-brake equipped trailer shall be
capable of transmitting a malfunction signal from the antilock brake
system(s) of the trailer(s) it tows to the vehicle in front of the
trailer. The ABS malfunction circuit and signal shall meet the
requirements of FMVSS No. 121 (49 CFR 571.121, S5.2.3.2).

(e) Exterior ABS malfunction indicator lamps for trailers. Each
trailer (including a trailer converter dolly) manufactured on or after
March 1, 1998 and before March 1, 2009, and subject to the requirements
of paragraph (c)(2) of this section, shall be equipped with an ABS
malfunction indicator lamp which meets the requirements of FMVSS No. 121
(49 CFR 571.121, S5.2.3.3).

Sec. 393.60 Glazing in specified openings.

(a) Glazing material. Glazing material used in windshields, windows,
and doors on a motor vehicle manufactured on or after December 25, 1968,
shall at a minimum meet the requirements of Federal Motor Vehicle Safety
Standard (FMVSS) No. 205 in effect on the date of manufacture of the
motor vehicle. The glazing material shall be marked in accordance with
FMVSS No. 205 (49 CFR 571.205, S6).

(b) Windshields required. Each bus, truck and truck-tractor shall be
equipped with a windshield. Each windshield or portion of a multi-piece
windshield shall be mounted using the full periphery of the glazing
material.

(c) Windshield condition. With the exception of the conditions
listed in paragraphs (c)(1), (c)(2), and (c)(3) of this section, each
windshield shall be free of discoloration or damage in the area
extending upward from the height of the top of the steering wheel
(excluding a 51 mm (2 inch) border at the top of the windshield) and
extending from a 25 mm (1 inch) border at each side of the windshield or
windshield panel. Exceptions:

(1) Coloring or tinting which meets the requirements of paragraph
(d) of this section;

(2) Any crack that is not intersected by any other cracks;

(3) Any damaged area which can be covered by a disc 19 mm (\3/4\
inch) in diameter if not closer than 76 mm (3 inches) to any other
similarly damaged area.

(d) Coloring or tinting of windshields and windows. Coloring or
tinting of windshields and the windows to the immediate right and left
of the driver is allowed, provided the parallel luminous transmittance
through the colored or tinted glazing is not less than 70 percent of the
light at normal incidence in those portions of the windshield or windows
which are marked as having a parallel luminous transmittance of not less
than 70 percent. The transmittance restriction does not apply to other
windows on the commercial motor vehicle.

(e) Prohibition on obstructions to the driver's field of view--(1)
Devices mounted at the top of the windshield. Antennas, transponders,
and similar devices must not be mounted more than 152 mm (6 inches)
below the upper edge of the windshield. These devices must be located
outside the area swept by the windshield wipers, and outside the
driver's sight lines to the road and highway signs and signals.

(2) Decals and stickers mounted on the windshield. Commercial
Vehicle Safety Alliance (CVSA) inspection decals, and stickers and/or
decals required under Federal or State laws may be placed at the bottom
or sides of the windshield provided such decals or stickers do not
extend more than 115 mm (4\1/2\ inches) from the bottom of the
windshield and are located outside the area swept by the windshield
wipers, and outside the driver's sight lines to the road and highway
signs or signals.

Sec. 393.61 Window construction.

(a) Windows in trucks and truck tractors. Every truck and truck
tractor, except vehicles engaged in armored car service, shall have, in
addition to the area provided by the windshield, at least one window on
each side of the driver's compartment, which window shall have
sufficient area to contain either an ellipse having a major axis of 18
inches and a minor axis of 13 inches or an opening containing 200 square
inches formed by a rectangle 13 inches by 17\3/4\ inches with corner
arcs of 6-inch maximum radius. The major axis of the ellipse and the
long axis of the rectangle shall not make an angle of more than 45
degrees with the surface on which the unladen vehicle stands; however,
if the cab is designed with a folding door or doors or with clear
openings where doors or windows are customarily located, then no windows
shall be required in such locations.

(b) Bus windows. (1) Except as provided in paragraph (b)(3) of this
section a bus manufactured before September 1, 1973, having a seating
capacity of more than eight persons shall have, in addition to the area
provided by the windshield, adequate means of escape for passengers
through windows. The adequacy of such means shall be determined in
accordance with the following standards: For each seated passenger space
provided, inclusive of the driver there shall be at least 67 square
inches of glazing if such glazing is not contained in a push-out window;
or at least 67 square inches of free opening resulting from opening of a
push-out type window. No area shall be included in this minimum
prescribed area unless it will provide an unobstructed opening
sufficient to contain an ellipse having a major axis of 18 inches and a
minor axis of 13 inches or an opening containing 200 square inches
formed by a rectangle 13 inches by 17\3/4\ inches with corner arcs of 6-
inch maximum radius. The major axis of the elipse and the long axis of
the rectangle shall make an angle of not more than 45[deg] with the
surface on which the unladen vehicle stands. The area shall be measured
either by removal of the glazing if not of the push-out type or of the
movable sash if of the push-out type, and it shall be either glazed with
laminated safety glass or comply with paragraph (c) of this section. No
less than 40 percent of such prescribed glazing or opening shall be on
one side of any bus.

(2) A bus, including a school bus, manufactured on and after
September 1, 1973, having a seating capacity of more than 10 persons
shall have emergency exits in conformity with Federal Motor Vehicle
Safety Standard No. 217, part 571 of this title.

(3) A bus manufactured before September 1, 1973, may conform to
Federal Motor Vehicle Safety Standard No. 217, part 571 of this title,
in lieu of conforming to paragraph (b)(1) of this section.

(c) Push-out window requirements. (1) Except as provided in
paragraph (c)(3) of this section, every glazed opening in a bus
manufactured before September 1, 1973, and having a seating capacity of
more than eight persons, used to satisfy the requirements of paragraph
(b)(1) of this section, if not glazed with laminated safety glass, shall
have a frame or sash so designed, constructed, and maintained that it
will yield outwardly to provide the required free opening when subjected
to the drop test specified in Test 25 of the American Standard Safety
Code referred to in Sec. 393.60. The height of drop required to open
such push-out windows shall not exceed the height of drop required to
break the glass in the same window when glazed with the type of
laminated glass specified in Test 25 of the Code. The sash for such
windows shall be constructed of such material and be of such design and
construction as to be continuously capable of complying with the above
requirement.

(2) On a bus manufactured on and after September 1, 1973, having a
seating capacity of more than 10 persons, each push-out window shall
conform to Federal Motor Vehicle Safety Standard No. 217, (Sec. 571.217)
of this title.

(3) A bus manufactured before September 1, 1973, may conform to
Federal Motor Vehicle Safety Standard No. 217 (Sec. 571.217) of this
title, in lieu of conforming to paragraph (c)(1) of this section.

Sec. 393.62 Window obstructions.

Windows, if otherwise capable of complying with Sec. 393.61 (a) and
(b), shall not be obstructed by bars or other such means located either
inside or outside such windows such as would hinder the escape of
occupants unless such bars or other such means are so constructed as to
provide a clear opening, at least equal to the opening provided by the
window to which it is adjacent, when subjected to the same test
specified in Sec. 393.61(c). The point of application of such test force
shall be such as will be most likely to result in the removal of the
obstruction.

Sec. 393.63 Windows, markings.

(a) On a bus manufactured before September 1, 1973, each bus push-
out window and any other bus escape window glazed with laminated safety
glass required in Sec. 393.61 shall be identified as such by clearly
legible and visible signs, lettering, or decalcomania. Such marking
shall include appropriate wording to indicate that it is an escape
window and also the method to be used for obtaining emergency exit.

(b) On a bus manufactured on and after September 1, 1973, emergency
exits required in Sec. 393.61 shall be marked to conform to Federal
Motor Vehicle Safety Standard No. 217 (Sec. 571.217), of this title.

(c) A bus manufactured before September 1, 1973, may mark emergency
exits to conform to Federal Motor Vehicle Safety Standard No. 217
(Sec. 571.217), of this title in lieu of conforming to paragraph (a) of
this section.

Sec. 393.65 All fuel systems.

Authority: Sec. 204, Interstate Commerce Act, as amended, 49 U.S.C.
304; sec. 6, Department of Transportation Act, 49 U.S.C. 1655;
delegation of authority at 49 CFR 1.48 and 389.4.

(a) Application of the rules in this section. The rules in this
section apply to systems for containing and supplying fuel for the
operation of motor vehicles or for the operation of auxiliary equipment
installed on, or used in connection with, motor vehicles.

(b) Location. Each fuel system must be located on the motor vehicle
so that--

(1) No part of the system extends beyond the widest part of the
vehicle;

(2) No part of a fuel tank is forward of the front axle of a power
unit;

(3) Fuel spilled vertically from a fuel tank while it is being
filled will not contact any part of the exhaust or electrical systems of
the vehicle, except the fuel level indicator assembly;

(4) Fill pipe openings are located outside the vehicle's passenger
compartment and its cargo compartment;

(5) A fuel line does not extend between a towed vehicle and the
vehicle that is towing it while the combination of vehicles is in
motion; and

(6) No part of the fuel system of a bus manufactured on or after
January 1, 1973, is located within or above the passenger compartment.

(c) Fuel tank installation. Each fuel tank must be securely attached
to the motor vehicle in a workmanlike manner.

(d) Gravity or syphon feed prohibited. A fuel system must not supply
fuel by gravity or syphon feed directly to the carburetor or injector.

(e) Selection control valve location. If a fuel system includes a
selection control valve which is operable by the driver to regulate the
flow of fuel from two or more fuel tanks, the valve must be installed so
that either--

(1) The driver may operate it while watching the roadway and without
leaving his/her driving position; or

(2) The driver must stop the vehicle and leave his/her seat in order
to operate the valve.

(f) Fuel lines. A fuel line which is not completely enclosed in a
protective housing must not extend more than 2 inches below the fuel
tank or its sump. Diesel fuel crossover, return, and withdrawal lines
which extend below the bottom of the tank or sump must be protected
against damage from impact. Every fuel line must be--

(1) Long enough and flexible enough to accommodate normal movements
of the parts to which it is attached without incurring damage; and

(2) Secured against chafing, kinking, or other causes of mechanical
damage.

(g) Excess flow valve. When pressure devices are used to force fuel
from a fuel tank, a device which prevents the flow of fuel from the fuel
tank if the fuel feed line is broken must be installed in the fuel
system.

Sec. 393.67 Liquid fuel tanks.

(a) Application of the rules in this section. (1) A liquid fuel tank
manufactured on or after January 1, 1973, and a side-mounted gasoline
tank must conform to all the rules in this section.

(2) A diesel fuel tank manufactured before January 1, 1973, and
mounted on a bus must conform to the rules in paragraphs (c)(7)(iii) and
(d)(2) of this section.

(3) A diesel fuel tank manufactured before January 1, 1973, and
mounted on a vehicle other than a bus must conform to the rules in
paragraph (c)(7)(iii) of this section.

(4) A gasoline tank, other than a side-mounted gasoline tank,
manufactured before January 1, 1973, and mounted on a bus must conform
to the rules in paragraphs (c) (1) through (10) and (d)(2) of this
section.

(5) A gasoline tank, other than a side-mounted gasoline tank,
manufactured before January 1, 1973, and mounted on a vehicle other than
a bus must conform to the rules in paragraphs (c) (1) through (10),
inclusive, of this section.

(6) Private motor carrier of passengers. Motor carriers engaged in
the private transportation of passengers may continue to operate a
commercial motor vehicle which was not subject to this section or 49 CFR
571.301 at the time of its manufacture, provided the fuel tank of such
vehicle is maintained to the original manufacturer's standards.

(b) Definitions. As used in this section--

(1) The term liquid fuel tank means a fuel tank designed to contain
a fuel that is liquid at normal atmospheric pressures and temperatures.

(2) A side-mounted fuel tank is a liquid fuel tank which--

(i) If mounted on a truck tractor, extends outboard of the vehicle
frame and outside of the plan view outline of the cab; or

(ii) If mounted on a truck, extends outboard of a line parallel to
the longitudinal centerline of the truck and tangent to the outboard
side of a front tire in a straight ahead position. In determining
whether a fuel tank on a truck or truck tractor is side-mounted, the
fill pipe is not considered a part of the tank.

(c) Construction of liquid fuel tanks--

(1) Joints. Joints of a fuel
tank body must be closed by arc-, gas-, seam-, or spot-welding, by
brazing, by silver soldering, or by techniques which provide heat
resistance and mechanical securement at least equal to those
specifically named. Joints must not be closed solely by crimping or by
soldering with a lead-based or other soft solder.

(2) Fittings. The fuel tank body must have flanges or spuds suitable
for the installation of all fittings.

(3) Threads. The threads of all fittings must be Dryseal American
Standard Taper Pipe Thread or Dryseal SAE Short Taper Pipe Thread,
specified in Society of Automotive Engineers Standard J476, as contained
in the 1971 edition of the ``SAE Handbook,'' except that straight
(nontapered) threads may be used on fittings having integral flanges and
using gaskets for sealing. At least four full threads must be in
engagement in each fitting.

(4) Drains and bottom fittings. (i) Drains or other bottom fittings
must not extend more than three-fourths of an inch below the lowest part
of the fuel tank or sump.

(ii) Drains or other bottom fittings must be protected against
damage from impact.

(iii) If a fuel tank has drains the drain fittings must permit
substantially complete drainage of the tank.

(iv) Drains or other bottom fittings must be installed in a flange
or spud designed to accommodate it.

(5) Fuel withdrawal fittings. Except for diesel fuel tanks, the
fittings through which fuel is withdrawn from a fuel tank must be
located above the normal level of fuel in the tank when the tank is
full.

(6) [Reserved]

(7) Fill pipe. (i) Each fill pipe must be designed and constructed
to minimize the risk of fuel spillage during fueling operations and when
the vehicle is involved in a crash.

(ii) The fill pipe and vents of a fuel tank having a capacity of
more than 25 gallons of fuel must permit filling the tank with fuel at a
rate of at least 20 gallons per minute without fuel spillage.

(iii) Each fill pipe must be fitted with a cap that can be fastened
securely over the opening in the fill pipe. Screw threads or a bayonet-
type joint are methods of conforming to the requirements of this
subdivision.

(8) Safety venting system. A liquid fuel tank with a capacity of
more than 25 gallons of fuel must have a venting system which, in the
event the tank is subjected to fire, will prevent internal tank pressure
from rupturing the tank's body, seams, or bottom opening (if any).

(9) Pressure resistance. The body and fittings of a liquid fuel tank
with a capacity of more than 25 gallons of fuel must be capable of
withstanding an internal hydrostatic pressure equal to 150 percent of
the maximum internal pressure reached in the tank during the safety
venting systems test specified in paragraph (d)(1) of this section.

(10) Air vent. Each fuel tank must be equipped with a nonspill air
vent (such as a ball check). The air vent may be combined with the fill-
pipe cap or safety vent, or it may be a separate unit installed on the
fuel tank.

(11) Markings. If the body of a fuel tank is readily visible when
the tank is installed on the vehicle, the tank must be plainly marked
with its liquid capacity. The tank must also be plainly marked with a
warning against filling it to more than 95 percent of its liquid
capacity.

(12) Overfill restriction. A liquid fuel tank manufactured on or
after January 1, 1973, must be designed and constructed so that--

(i) The tank cannot be filled, in a normal filling operation, with a
quantity of fuel that exceeds 95 percent of the tank's liquid capacity;
and

(ii) When the tank is filled, normal expansion of the fuel will not
cause fuel spillage.

(d) Liquid fuel tank tests. Each liquid fuel tank must be capable of
passing the tests specified in paragraphs (d) (1) and (2) of this
section. \1\

(1) Safety venting system test--(i) Procedure. Fill the tank three-
fourths full with fuel, seal the fuel feed outlet, and invert the tank.
When the fuel temperature is between 50 [deg]F. and 80 [deg]F., apply an
enveloping flame to the tank so that the temperature of the fuel rises
at a rate of not less than 6 [deg]F. and not more than 8 [deg]F. per
minute.

(ii) Required performance. The safety venting system required by
paragraph (c)(8) of this section must activate before the internal
pressure in the tank exceeds 50 pounds per square inch, gauge, and the
internal pressure must not thereafter exceed the pressure at which the
system activated by more than five pounds per square inch despite any
further increase in the temperature of the fuel.

(2) Leakage test--(i) Procedure. Fill the tank to capacity with fuel
having a temperature between 50 [deg]F. and 80 [deg]F. With the fill-
pipe cap installed, turn the tank through an angle of 150[deg] in any
direction about any axis from its normal position.

(ii) Required performance. Neither the tank nor any fitting may leak
more than a total of one ounce by weight of fuel per minute in any
position the tank assumes during the test.
(e) Side-mounted liquid fuel tank tests. Each side-mounted liquid
fuel tank must be capable of passing the tests specified in paragraphs
(e) (1) and (2) of this section and the tests specified in paragraphs
(d) (1) and (2) of this section. \1\
---------------------------------------------------------------------------

\1\ The specified tests are a measure of performance only.
Manufacturers and carriers may use any alternative procedures which
assure that their equipment meets the required performance criteria.
---------------------------------------------------------------------------

(1) Drop test--(i) Procedure. Fill the tank with a quantity of water
having a weight equal to the weight of the maximum fuel load of the tank
and drop the tank 30 feet onto an unyielding surface so that it lands
squarely on one corner.

(ii) Required performance. Neither the tank nor any fitting may leak
more than a total of 1 ounce by weight of water per minute.

(2) Fill-pipe test--(i) Procedure. Fill the tank with a quantity of
water having a weight equal to the weight of the maximum fuel load of
the tank and drop the tank 10 feet onto an unyielding surface so that it
lands squarely on its fill-pipe.

(ii) Required performance. Neither the tank nor any fitting may leak
more than a total of 1 ounce by weight of water per minute.

(f) Certification and markings. Each liquid fuel tank shall be
legibly and permanently marked by the manufacturer with the following
minimum information:

(1) The month and year of manufacture,

(2) The manufacturer's name on tanks manufactured on and after July
1, 1988, and means of identifying the facility at which the tank was
manufactured, and

(3) A certificate that it conforms to the rules in this section
applicable to the tank. The certificate must be in the form set forth in
either of the following:

(i) If a tank conforms to all rules in this section pertaining to
side-mounted fuel tanks: ``Meets all FMCSA side-mounted tank
requirements.''

(ii) If a tank conforms to all rules in this section pertaining to
tanks which are not side-mounted fuel tanks: ``Meets all FMCSA
requirements for non-side-mounted fuel tanks.''

(iii) The form of certificate specified in paragraph (f)(3) (i) or
(ii) of this section may be used on a liquid fuel tank manufactured
before July 11, 1973, but it is not mandatory for liquid fuel tanks
manufactured before March 7, 1989. The form of certification
manufactured on or before March 7, 1989, must meet the requirements in
effect at the time of manufacture.

Sec. 393.69 Liquefied petroleum gas systems.

(a) A fuel system that uses liquefied petroleum gas as a fuel for
the operation of a motor vehicle or for the operation of auxiliary
equipment installed on, or used in connection with, a motor vehicle must
conform to the ``Standards for the Storage and Handling of Liquefied
Petroleum Gases'' of the National Fire Protection Association, Battery
March Park, Quincy, MA 02269, as follows:

(1) A fuel system installed before December 31, 1962, must conform
to the 1951 edition of the Standards.

(2) A fuel system installed on or after December 31, 1962, and
before January 1, 1973, must conform to Division IV of the June 1959
edition of the Standards.

(3) A fuel system installed on or after January 1, 1973, and
providing fuel for propulsion of the motor vehicle must conform to
Division IV of the 1969 edition of the Standards.

(4) A fuel system installed on or after January 1, 1973, and
providing fuel for the operation of auxiliary equipment must conform to
Division VII of the 1969 edition of the Standards.

(b) When the rules in this section require a fuel system to conform
to a specific edition of the Standards, the fuel system may conform to
the applicable provisions in a later edition of the Standards specified
in this section.

(c) The tank of a fuel system must be marked to indicate that the
system conforms to the Standards.

Sec. 393.70 Coupling devices and towing methods, except for driveaway-towaway operations.

(a) Tracking. When two or more vehicles are operated in combination,
the coupling devices connecting the vehicles shall be designed,
constructed, and installed, and the vehicles shall be designed and
constructed, so that when the combination is operated in a straight line
on a level, smooth, paved surface, the path of the towed vehicle will
not deviate more than 3 inches to either side of the path of the vehicle
that tows it.

(b) Fifth wheel assemblies--(1) Mounting--(i) Lower half. The lower
half of a fifth wheel mounted on a truck tractor or converter dolly must
be secured to the frame of that vehicle with properly
designed brackets, mounting plates or angles and properly tightened
bolts of adequate size and grade, or devices that provide equivalent
security. The installation shall not cause cracking, warping, or
deformation of the frame. The installation must include a device for
positively preventing the lower half of the fifth wheel from shifting on
the frame to which it is attached.

(ii) Upper half. The upper half of a fifth wheel must be fastened to
the motor vehicle with at least the same security required for the
installation of the lower half on a truck tractor or converter dolly.

(2) Locking. Every fifth wheel assembly must have a locking
mechanism. The locking mechanism, and any adapter used in conjunction
with it, must prevent separation of the upper and lower halves of the
fifth wheel assembly unless a positive manual release is activated. The
release may be located so that the driver can operate it from the cab.
If a motor vehicle has a fifth wheel designed and constructed to be
readily separable, the fifth wheel locking devices shall apply
automatically on coupling.

(3) Location. The lower half of a fifth wheel shall be located so
that, regardless of the condition of loading, the relationship between
the kingpin and the rear axle or axles of the towing motor vehicle will
properly distribute the gross weight of both the towed and towing
vehicles on the axles of those vehicles, will not unduly interfere with
the steering, braking, and other maneuvering of the towing vehicle, and
will not otherwise contribute to unsafe operation of the vehicles
comprising the combination. The upper half of a fifth wheel shall be
located so that the weight of the vehicles is properly distributed on
their axles and the combination of vehicles will operate safely during
normal operation.

(c) Towing of full trailers. A full trailer must be equipped with a
tow-bar and a means of attaching the tow-bar to the towing and towed
vehicles. The tow-bar and the means of attaching it must--

(1) Be structurally adequate for the weight being drawn;

(2) Be properly and securely mounted;

(3) Provide for adequate articulation at the connection without
excessive slack at that location; and

(4) Be provided with a locking device that prevents accidental
separation of the towed and towing vehicles. The mounting of the trailer
hitch (pintle hook or equivalent mechanism) on the towing vehicle must
include reinforcement or bracing of the frame sufficient to produce
strength and rigidity of the frame to prevent its undue distortion.

(d) Safety devices in case of tow-bar failure or disconnection.
Every full trailer and every converter dolly used to convert a
semitrailer to a full trailer must be coupled to the frame, or an
extension of the frame, of the motor vehicle which tows it with one or
more safety devices to prevent the towed vehicle from breaking loose in
the event the tow-bar fails or becomes disconnected. The safety device
must meet the following requirements:

(1) The safety device must not be attached to the pintle hook or any
other device on the towing vehicle to which the tow-bar is attached.
However, if the pintle hook or other device was manufactured prior to
July 1, 1973, the safety device may be attached to the towing vehicle at
a place on a pintle hook forging or casting if that place is independent
of the pintle hook.

(2) The safety device must have no more slack than is necessary to
permit the vehicles to be turned properly.

(3) The safety device, and the means of attaching it to the
vehicles, must have an ultimate strength of not less than the gross
weight of the vehicle or vehicles being towed.

(4) The safety device must be connected to the towed and towing
vehicles and to the tow-bar in a manner which prevents the tow-bar from
dropping to the ground in the event it fails or becomes disconnected.

(5) Except as provided in paragraph (d)(6) of this section, if the
safety device consists of safety chains or cables, the towed vehicle
must be equipped with either two safety chains or cables or with a
bridle arrangement of a single chain or cable attached to its frame or
axle at two points as far apart as the configuration of the frame or
axle permits. The safety chains or cables shall be either two separate
pieces, each equipped with a hook or other means for attachment to the towing
vehicle, or a single piece leading along each side of the tow-bar from
the two points of attachment on the towed vehicle and arranged into a
bridle with a single means of attachment to be connected to the towing
vehicle. When a single length of cable is used, a thimble and twin-base
cable clamps shall be used to form the forward bridle eye. The hook or
other means of attachment to the towing vehicle shall be secured to the
chains or cables in a fixed position.

(6) If the towed vehicle is a converter dolly with a solid tongue
and without a hinged tow-bar or other swivel between the fifth wheel
mounting and the attachment point of the tongue eye or other hitch
device--

(i) Safety chains or cables, when used as the safety device for that
vehicle, may consist of either two chains or cables or a single chain or
cable used alone;

(ii) A single safety device, including a single chain or cable used
alone as the safety device, must be in line with the centerline of the
trailer tongue; and

(iii) The device may be attached to the converter dolly at any point
to the rear of the attachment point of the tongue eye or other hitch
device.

(7) Safety devices other than safety chains or cables must provide
strength, security of attachment, and directional stability equal to, or
greater than, safety chains or cables installed in accordance with
paragraphs (d) (5) and (6) of this section.

(8) When two safety devices, including two safety chains or cables,
are used and are attached to the towing vehicle at separate points, the
points of attachment on the towing vehicle shall be located equally
distant from, and on opposite sides of, the centerline of the towing
vehicle. Where two chains or cables are attached to the same point on
the towing vehicle, and where a bridle or a single chain or cable is
used, the point of attachment must be on the longitudinal centerline of
the towing vehicle. A single safety device, other than a chain or cable,
must also be attached to the towing vehicle at a point on its
longitudinal centerline.

Sec. 393.71 Coupling devices and towing methods, driveaway-towaway operations.

(a) Number in combination.

(1) No more than three saddle-mounts may be used in any combination.

(2) No more than one tow-bar may be used in any combination.

(3) When motor vehicles are towed by means of triple saddle-mounts,
the towed vehicles shall have brakes acting on all wheels which are in
contact with the roadway.

(b) Carrying vehicles on towing vehicle. (1) When adequately and
securely attached by means equivalent in security to that provided in
paragraph (j)(2) of this section, a motor vehicle or motor vehicles may
be full-mounted on the structure of a towing vehicle engaged in any
driveaway-towaway operation.

(2) No motor vehicle or motor vehicles may be full-mounted on a
towing vehicle unless the relationship of such full-mounted vehicles to
the rear axle or axles results in proper distribution of the total gross
weight of the vehicles and does not unduly interfere with the steering,
braking, or maneuvering of the towing vehicle, or otherwise contribute
to the unsafe operation of the vehicles comprising the combination.

(c) Carrying vehicles on towed vehicles. (1) When adequately and
securely attached by means equivalent in security to that provided in
paragraph (j)(2) of this section, a motor vehicle or motor vehicles may
be full-mounted on the structure of towed vehicles engaged in any
driveaway-towaway operation.

(2) No motor vehicle shall be full-mounted on a motor vehicle towed
by means of a tow-bar unless the towed vehicle is equipped with brakes
and is provided with means for effective application of brakes acting on
all wheels and is towed on its own wheels.

(3) No motor vehicle or motor vehicles shall be full-mounted on a
motor vehicle towed by means of a saddle-mount unless the center line of
the kingpin or equivalent means of attachment of such towed vehicle
shall be so located on the towing vehicle that the relationship to the
rear axle or axles results in proper distribution of the total gross
weight of the vehicles and does not unduly interfere with the steering,
braking, or maneuvering of the towing vehicle or otherwise 
contribute to the unsafe operation of
vehicles comprising the combination; and unless a perpendicular to the
ground from the center of gravity of the full-mounted vehicles lies
forward of the center line of the rear axle of the saddle-mounted
vehicle.

(4) If a motor vehicle towed by means of a double saddle-mount has
any vehicle full-mounted on it, such saddle-mounted vehicle shall at all
times while so loaded have effective brakes acting on those wheels which
are in contact with the roadway.

(d) Bumper tow-bars on heavy vehicles prohibited. Tow-bars of the
type which depend upon the bumpers as a means of transmitting forces
between the vehicles shall not be used to tow a motor vehicle weighing
more than 5,000 pounds.

(e) Front wheels of saddle-mounted vehicles restrained. A motor
vehicle towed by means of a saddle-mount shall have the motion of the
front wheels restrained if under any condition of turning of such wheels
they will project beyond the widest part of either the towed or towing
vehicle.

(f) Vehicles to be towed in forward position. Unless the steering
mechanism is adequately locked in a straight-forward position, all motor
vehicles towed by means of a saddle-mount shall be towed with the front
end mounted on the towing vehicle.

(g) Means required for towing. (1) No motor vehicle or motor
vehicles shall be towed in driveaway-towaway operations by means other
than tow-bar or saddle-mount connections which shall meet the
requirements of this section.

(2) For the purpose of the regulations of this part:

(i) Coupling devices such as those used for towing house trailers
and employing ball and socket connections shall be considered as tow-
bars.

(ii) Motor vehicles or parts of motor vehicles adequately, securely,
and rigidly attached by devices meeting the requirements of paragraph
(n) of this section shall be considered as one vehicle in any position
in any combination.

(h) Requirements for tow-bars. Tow-bars shall comply with the
following requirements:

(1) Tow-bars, structural adequacy and mounting. Every tow-bar shall
be structurally adequate and properly installed and maintained. To
insure that it is structurally adequate, it must, at least, meet the
requirements of the following table:

\1\ The required strength of tow-bars for towed vehicles of 15,000
pounds and over gross weight and of new tow-bars acquired and used
after Sept. 30, 1948, for towed vehicles of 5,000 pounds and over
gross weight shall be computed by means of the following formulae:
Longitudinal strength=gross weight of towed vehicle x 1.3. Strength as
a beam=gross weight of towed vehicle x 0.6.

\2\ In testing, the whole unit shall be tested with all clamps, joints,
and pins so mounted and fastened as to approximate conditions of
actual operation.

\3\ This test shall be applicable only to tow-bars which are, in normal
operation, subjected to a bending movement such as tow-bars for house
trailers.

(2) Tow-bars, jointed. The tow-bar shall be so constructed as to
freely permit motion in both horizontal and vertical planes between the
towed and towing vehicles. The means used to provide the motion shall be
such as to prohibit the transmission of stresses under normal operation
between the towed and towing vehicles, except along the longitudinal
axis of the tongue or tongues.

(3) Tow-bar fastenings. The means used to transmit the stresses to
the chassis or frames of the towed and towing vehicles may be either
temporary structures or bumpers or other integral parts of the vehicles:
Provided, however, That the means used shall be so constructed,
installed, and maintained that when tested as an assembly, failure in
such members shall not occur when the weakest new tow-bar which is
permissible under paragraph (h)(1) of this section is subjected to the
tests given therein.

(4) Means of adjusting length. On tow-bars, adjustable as to length,
the means used to make such adjustment shall fit tightly and not 
result in any slackness or permit the tow-bar
to bend. With the tow-bar supported rigidly at both ends and with a load
of 50 pounds at the center, the sag, measured at the center, in any
direction shall not exceed 0.25 inch under any condition of adjustment
as to length.

(5) Method of clamping. Adequate means shall be provided for
securely fastening the tow-bar to the towed and towing vehicles.

(6) Tow-bar connection to steering mechanism. The tow-bar shall be
provided with suitable means of attachment to and actuation of the
steering mechanism, if any, of the towed vehicle. The attachment shall
provide for sufficient angularity of movement of the front wheels of the
towed vehicle so that it may follow substantially in the path of the
towing vehicle without cramping the tow-bar. The tow-bar shall be
provided with suitable joints to permit such movement.

(7) Tracking. The tow-bar shall be so designed, constructed,
maintained, and mounted as to cause the towed vehicle to follow
substantially in the path of the towing vehicle. Tow-bars of such design
on in our condition as to permit the towed vehicle to deviate more than
3 inches to either side of the path of a towing vehicle moving in a
straight line as measured from the center of the towing vehicle are
prohibited.

(8) Passenger car-trailer type couplings. Trailer couplings used for
driveaway-towaway operations of passenger car trailers shall conform to
Society of Automotive Engineers Standard No. J684c, ``Trailer Couplings
and Hitches--Automotive Type,'' July 1970. \1\
---------------------------------------------------------------------------

\1\ See footnote 1 to Sec. 393.24(c).
---------------------------------------------------------------------------

(9) Marking tow-bars. Every tow-bar acquired and used in driveaway-
towaway operations by a motor carrier shall be plainly marked with the
following certification of the manufacturer thereof (or words of
equivalent meaning):

This tow-bar complies with the requirements of the Federal Motor
Carrier Safety Administration for (maximum gross weight for which tow-
bar is manufactured) vehicles.
Allowable Maximum Gross Weight__________________________________________
Manufactured____________________________________________________________
(month and year)
by______________________________________________________________________
(name of manufacturer)

Tow-bar certification manufactured before the effective date of this
regulation must meet requirements in effect at the time of manufacture.

(10) Safety devices in case of tow-bar failure or disconnection. (i)
The towed vehicle shall be connected to the towing vehicle by a safety
device to prevent the towed vehicle from breaking loose in the event the
tow-bar fails or becomes disconnected. When safety chains or cables are
used as the safety device for that vehicle, at least two safety chains
or cables meeting the requirements of paragraph (h)(10)(ii) of this
section shall be used. The tensile strength of the safety device and the
means of attachment to the vehicles shall be at least equivalent to the
corresponding longitudinal strength for tow-bars required in the table
of paragraph (h)(1) of this section. If safety chains or cables are used
as the safety device, the required strength shall be the combined
strength of the combination of chains and cables.

(ii) If chains or cables are used as the safety device, they shall
be crossed and attached to the vehicles near the points of bumper
attachments to the chassis of the vehicles. The length of chain used
shall be no more than necessary to permit free turning of the vehicles.
The chains shall be attached to the tow-bar at the point of crossing or
as close to that point as is practicable.

(iii) A safety device other than safety chains or cables must
provide strength, security of attachment, and directional stability
equal to, or greater than, that provided by safety chains or cables
installed in accordance with paragraph (h)(10)(ii) of this section. A
safety device other than safety chains or cables must be designed,
constructed, and installed so that, if the tow-bar fails or becomes
disconnected, the tow-bar will not drop to the ground.

(i) [Reserved]

(j) Requirements for upper-half of saddle-mounts. The upper-half of
any saddle-mount shall comply with the following requirements:

(1) Upper-half connection to towed vehicle. The upper-half shall be
securely attached to the frame or axle of the towed vehicle by means of
U-bolts or other means providing at least equivalent security.

(2) U-bolts or other attachments. U-bolts used to attach the upper
half to the towed vehicle shall be made of steel rod, free of defects,
so shaped as to avoid at any point a radius of less than 1 inch:
Provided, however, That a lesser radius may be utilized if the U-bolt is
so fabricated as not to cause more than 5 percent reduction in cross-
sectional area at points of curvature, in which latter event the minimum
radius shall be one-sixteenth inch. U-bolts shall have a diameter not
less than required by the following table:

\1\ The total weight of all the vehicles being towed shall govern. If
other devices are used to accomplish the same purposes as U-bolts they
shall have at least equivalent strength of U-bolts made of mild steel.
Cast iron shall not be used for clamps or any other holding devices.

(3) U-bolts and points of support, location. The distance between
the most widely separated U-bolts shall not be less than 9 inches. The
distance between the widely separated points where the upper-half
supports the towed vehicle shall not be less than 9 inches, except that
saddle-mounts employing ball and socket joints shall employ a device
which clamps the axle of the towed vehicle throughout a length of not
less than 5 inches.

(4) Cradle-type upper-halves, specifications. Upper-halves of the
cradle-type using vertical members to restrain the towed vehicle from
relative movement in the direction of motion of the vehicles shall be
substantially constructed and adequate for the purpose. Such cradle-
mounts shall be equipped with at least one bolt or equivalent means to
provide against relative vertical movement between the upper-half and
the towed vehicle. Bolts, if used, shall be at least one-half inch in
diameter. Devices using equivalent means shall have at least equivalent
strength. The means used to provide against relative vertical motion
between the upper-half and the towed vehicle shall be such as not to
permit a relative motion of over one-half inch. The distance between the
most widely separated points of support between the upper-half and the
towed vehicle shall be at least 9 inches.

(5) Lateral movement of towed vehicle.(i) Towed vehicles having a
straight axle or an axle having a drop of less than 3 inches, unless the
saddle-mount is constructed in accordance with paragraph (m)(2) of this
section, shall be securely fastened by means of chains or cables to the
upper-half so as to insure against relative lateral motion between the
towed vehicle and the upper-half. The chains or cables shall be at least
\3/16\-inch diameter and secured by bolts of at least equal diameter.

(ii) Towed vehicles with an axle with a drop of 3 inches or more, or
connected by a saddle-mount constructed in accordance with paragraph
(m)(2) of this section, need not be restrained by chains or cables
provided that the upper-half is so designed as to provide against such
relative motion.

(iii) Chains or cables shall not be required if the upper-half is so
designed as positively to provide against lateral movement of the axle.

(k) Requirements for lower half of saddle-mounts. The lower half of
any saddle-mount shall comply with the following requirements:

(1) U-bolts or other attachments. U-bolts used to attach the lower
half to the towing vehicle shall be made of steel rod, free of defects,
so shaped as to avoid at any point a radius of less than 1 inch:
Provided, however, That a lesser radius may be utilized if the U-bolt is
so fabricated as not to cause more than 5 percent reduction in cross-
sectional area at points of curvature, in which latter event the minimum
radius shall be one-sixteenth inch. U-bolts shall have a total cross-
sectional area not less than as required by the following table:

\1\ The total weight of all the vehicles being towed shall govern. If
other devices are used to accomplish the same purposes as U-bolts they
shall have at least equivalent strength of U-bolts made of mild steel.
Cast iron shall not be used for clamps or any other holding devices.

(2) Shifting. Adequate provision shall be made by design and
installation to provide against relative movement between the lower-half
and the towing vehicle especially during periods of rapid acceleration
and deceleration. To insure against shifting, designs of the tripod type
shall be equipped with adequate and securely fastened hold-back chains
or similar devices.

(3) Swaying. (i) Adequate provision shall be made by design and
installation to provide against swaying or lateral movement of the towed
vehicle relative to the towing vehicle. To insure against swaying,
lower-halves designed with cross-members attached to but separable from
vertical members shall have such cross-members fastened to the vertical
members by at least two bolts on each side. Such bolts shall be of at
least equivalent cross-sectional area as those required for U-bolts for
the corresponding saddle-mount as given in the table in paragraph (k)(1)
of this section. The minimum distance between the most widely separated
points of support of the cross-member by the vertical member shall be
three inches as measured in a direction parallel to the longitudinal
axis of the towing vehicle.

(ii) The lower-half shall have a bearing surface on the frame of the
towing vehicle of such dimensions that the pressure exerted by the
lower-half upon the frame of the towing vehicle shall not exceed 200
pounds per square inch under any conditions of static loading. Hardwood
blocks or blocks of other suitable material, such as hard rubber,
aluminum or brakelining, if used between the lower half and the frame of
the towing vehicle shall be at least \1/2\ inch thick, 3 inches wide,
and a combined length of 6 inches.

(iii) Under no condition shall the highest point of support of the
towed vehicle by the upper-half be more than 24 inches, measured
vertically, above the top of the frame of the towing vehicle, measured
at the point where the lower-half rests on the towing vehicle.

(4) Wood blocks. (i) Hardwood blocks of good quality may be used to
build up the height of the front end of the towed vehicle, provided that
the total height of such wood blocks shall not exceed 8 inches and not
over two separate pieces are placed upon each other to obtain such
height; however, hardwood blocks, not over 4 in number, to a total
height not to exceed 14 inches, may be used if the total cross-sectional
area of the U-bolts used to attach the lower-half of the towing vehicle
is at least 50 percent greater than that required by the table contained
in paragraph (k)(1) of this section, or, if other devices are used in
lieu of U-bolts, they shall provide for as great a resistance to bending
as is provided by the larger U-bolts above prescribed.

(ii) Hardwood blocks must be at least 4 inches in width and the
surfaces between blocks or block and lower-half or block and upper-half
shall be planed and so installed and maintained as to minimize any
tendency of the towed vehicle to sway or rock.

(5) Cross-member, general requirements. The cross-member, which is
that part of the lower-half used to distribute the weight of the towed
vehicle equally to each member of the frame of the towing vehicle, if
used, shall be structurally adequate and properly installed and
maintained adequately to perform this function.

(6) Cross-member, use of wood. No materials, other than suitable
metals, shall be used as the cross-member, and wood may not be used
structurally in any manner that will result in its being subject to
tensile stresses. Wood may be used in cross-members if supported
throughout its length by suitable metal cross-members.

(7) Lower half strength. The lower half shall be capable of
supporting the loads given in the following table. For the purpose of
test, the saddle-mount shall be mounted as normally operated and the
load applied through the upper half:

\1\ The total weight of all the vehicles being towed shall govern.

(l) Requirements for kingpins of saddle-mounts. The kingpin of any
saddle-mount shall comply with the following requirements:

(1) Kingpin size. (i) Kingpins shall be constructed of steel
suitable for the purpose, free of defects, and having a diameter not
less than required by the following table:

\1\ The total weight of all the vehicles being towed shall govern.

\2\ High-tensile steel is steel having a minimum ultimate strength of 65,000 pounds per square inch.

(ii) If a ball and socket joint is used in place of a kingpin, the
diameter of the neck of the ball shall be at least equal to the diameter
of the corresponding solid kingpin given in the above table. If hollow
kingpins are used, the metallic cross-sectional area shall be at least
equal to the cross-sectional area of the corresponding solid kingpin.

(2) Kingpin fit. If a kingpin bushing is not used, the king-pin
shall fit snugly into the upper and lower-halves but shall not bind.
Those portions of the upper or lower-halves in moving contact with the
kingpin shall be smoothly machined with no rough or sharp edges. The
bearing surface thus provided shall not be less in depth than the radius
of the kingpin.

(3) Kingpin bushing on saddle-mounts. The kingpin of all new saddle-
mounts acquired and used shall be snugly enclosed in a bushing at least
along such length of the kingpin as may be in moving contact with either
the upper or lower-halves. The bearing surface thus provided shall not
be less in depth than the radius of the kingpin.

(4) Kingpin to restrain vertical motion. The kingpin shall be so
designed and installed as to restrain the upper-half from moving in a
vertical direction relative to the lower-half.

(m) Additional requirements for saddle-mounts. Saddle-mounts shall
comply with the following requirements:

(1) Bearing surface between upper and lower-halves. The upper and
lower-halves shall be so constructed and connected that the bearing
surface between the two halves shall not be less than 16 square inches
under any conditions of angularity between the towing and towed
vehicles: Provided, however, That saddle-mounts using a ball and socket
joint shall have a ball of such dimension that the static bearing load
shall not exceed 800 pounds per square inch, based on the projected
cross-sectional area of the ball: And further provided, That saddle-
mounts having the upper-half supported by ball, taper, or roller-
bearings shall not have such bearings loaded beyond the limits
prescribed for such bearings by the manufacturer thereof. The upper-half
shall rest evenly and smoothly upon the lower-half and the contact
surfaces shall be lubricated and maintained so that there shall be a
minimum of frictional resistance between the parts.

(2) Saddle-mounts, angularity. All saddle-mounts acquired and used
shall provide for angularity between the towing and towed vehicles due
to vertical curvatures of the highway. Such means shall not depend upon
either the looseness or deformation of the parts of either the saddle-
mount or the vehicles to provide for such angularity.

(3) Tracking. The saddle-mount shall be so designed, constructed,
maintained, and installed that the towed vehicle or vehicles will follow
substantially in the path of the towing vehicle without swerving. Towed
vehicles shall not deviate more than 3 inches to either side of the path
of the towing vehicle when moving in a straight line.

(4) Prevention of frame bending. Where necessary, provision shall be
made to prevent the bending of the frame of the towing vehicle by
insertion of suitable blocks inside the frame channel to prevent
kinking. The saddle-mount shall not be so located as to cause
deformation of the frame by reason of cantilever action.

(5) Extension of frame. No saddle-mount shall be located at a point
to the rear of the frame of a towing vehicle.

(6) Nuts, secured. All nuts used on bolts, U-bolts, king-pins, or in
any other part of the saddle-mount shall be secured against accidental
disconnection by means of cotter-keys, lock-washers, double nuts, safety
nuts, or equivalent means. Parts shall be so designed and installed that
nuts shall be fully engaged.

(7) Inspection of all parts. The saddle-mount shall be so designed
that it may be disassembled and each separate part inspected for worn,
bent, cracked, broken, or missing parts.

(8) Saddle-mounts, marking. Every new saddle-mount acquired and used
in driveaway-towaway operations by a motor carrier shall have the upper-
half and the lower-half separately marked with the following
certification of the manufacturer thereof (or words of equivalent
meaning).

This saddle-mount complies with the requirements of the Federal
Motor Carrier Safety Administration for vehicles up to 5,000 pounds (or
over 5,000 pounds):

Manufactured____________________________________________________________
                                                                                                    (Month and year)
by______________________________________________________________________
                                                                                          (Name of manufacturer)

(n) Requirements for devices used to connect motor vehicles or parts
of motor vehicles together to form one vehicle--(1) Front axle
attachment. The front axle of one motor vehicle intended to be coupled
with another vehicle as defined in paragraph (g)(2)(ii) of this section
shall be attached with U-bolts meeting the requirements of paragraph
(j)(2) of this section.

(2) Rear axle attachment. The rear axle of one vehicle shall be
coupled to the frame of the other vehicle by means of a connecting
device which when in place forms a rectangle. The device shall be
composed of two pieces, top and bottom. The device shall be made of 4-
inch by \1/2\-inch steel bar bent to shape and shall have the corners
reinforced with a plate at least 3 inches by \1/2\ inch by 8 inches
long. The device shall be bolted together with \3/4\-inch bolts and at
least three shall be used on each side. Wood may be used as spacers to
keep the frames apart and it shall be at least 4 inches square.

Sec. 393.75 Tires.

(a) No motor vehicle shall be operated on any tire that (1) has body
ply or belt material exposed through the tread or sidewall, (2) has any
tread or sidewall separation, (3) is flat or has an audible leak, or (4)
has a cut to the extent that the ply or belt material is exposed.

(b) Any tire on the front wheels of a bus, truck, or truck tractor
shall have a tread groove pattern depth of at least \4/32\ of an inch
when measured at any point on a major tread groove. The measurements
shall not be made where tie bars, humps, or fillets are located.

(c) Except as provided in paragraph (b) of this section, tires shall
have a tread groove pattern depth of at least \2/32\ of an inch when
measured in a major tread groove. The measurement shall not be made
where tie bars, humps or fillets are located.

(d) No bus shall be operated with regrooved, recapped or retreaded
tires on the front wheels.

(e) No truck or truck tractor shall be operated with regrooved tires
on the front wheels which have a load carrying capacity equal to or
greater than that of 8.25-20 8 ply-rating tires.

(f) Tire loading restrictions (except on manufactured homes). No
motor vehicle (except manufactured homes, which are governed by
paragraph (g) of this section) shall be operated with tires that carry a
weight greater than that marked on the sidewall of the tire or, in the
absence of such a marking, a weight greater than that specified for the
tires in any of the publications of any of the organizations listed in
Federal Motor Vehicle Safety Standard No. 119 (49 CFR 571.119, S5.1(b))
unless:

(1) The vehicle is being operated under the terms of a special
permit issued by the State; and

(2) The vehicle is being operated at a reduced speed to compensate
for the tire loading in excess of the manufacturer's rated capacity for
the tire. In no case shall the speed exceed 80 km/hr (50 mph).

(g)(1) Tire loading restrictions for manufactured homes built before
January 1, 2002. Manufactured homes that are labeled pursuant to 24 CFR
3282.362(c)(2)(i) before January 1, 2002, must not be transported on
tires that are loaded more than 18 percent over the load rating marked
on the sidewall of the tire or, in the absence of such a marking, more
than 18 percent over the load rating specified in any of the
publications of any of the organizations listed in FMVSS No. 119 (49 CFR
571.119, S5.1(b)). Manufactured homes labeled before January 1, 2002,
transported on tires overloaded by 9 percent or more must not be
operated at speeds exceeding 80 km/hr (50 mph).

(2) Tire loading restrictions for manufactured homes built on or
after January 1, 2002. Manufactured homes that are labeled pursuant to
24 CFR 3282.362(c)(2)(i) on or after January 1, 2002, must not be
transported on tires loaded beyond the load rating marked on the
sidewall of the tire or, in the absence of such a marking, the load
rating specified in any of the publications of any of the organizations
listed in FMVSS No. 119 (49 CFR 571.119, S5.1(b)).

(h) Tire inflation pressure. (1) No motor vehicle shall be operated
on a tire which has a cold inflation pressure less than that specified
for the load being carried.

(2) If the inflation pressure of the tire has been increased by heat
because of the recent operation of the vehicle, the cold inflation
pressure shall be estimated by subtracting the inflation buildup factor
shown in Table 1 from the measured inflation pressure.

Sec. 393.76 Sleeper berths.

(a) Dimensions--(1) Size. A sleeper berth must be at least the
following size:

\1\ In the case of a sleeper berth which utilizes an adjustable
mechanical suspension system, the required clearance can be measured
when the suspension system is adjusted to the height to which it would
settle when occupied by a driver.

(2) Shape. A sleeper berth installed on a motor vehicle on or after
January 1, 1953 must be of generally rectangular shape, except that the
horizontal corners and the roof corners may be rounded to radii not
exceeding 10\1/2\ inches.

(3) Access. A sleeper berth must be constructed so that an
occupant's ready entrance to, and exit from, the sleeper berth is not
unduly hindered.

(b) Location.

(1) A sleeper berth must not be installed in or on a
semitrailer or a full trailer other than a house trailer.

(2) A sleeper berth located within the cargo space of a motor
vehicle must be securely compartmentalized from the remainder of the
cargo space. A sleeper berth installed on or after January 1, 1953 must
be located in the cab or immediately adjacent to the cab and must be
securely fixed with relation to the cab.

(c) Exit from the berth.

(1) Except as provided in paragraph (c)(2)
of this section, there must be a direct and ready means of exit from a
sleeper berth into the driver's seat or compartment. If the sleeper
berth was installed on or after January 1, 1963, the exit must be a
doorway or opening at least 18 inches high and 36 inches wide. If the
sleeper berth was installed before January 1, 1963, the exit must have
sufficient area to contain an ellipse having a major axis of 24 inches
and a minor axis of 16 inches.

(2) A sleeper berth installed before January 1, 1953 must either:

(i) Conform to the requirements of paragraph (c)(1) of this section;
or

(ii) Have at least two exits, each of which is at least 18 inches
high and 21 inches wide, located at opposite ends of the vehicle and
useable by the occupant without the assistance of any other person.

(d) Communication with the driver. A sleeper berth which is not
located within the driver's compartment and has no direct entrance into
the driver's compartment must be equipped with a means of communication
between the occupant and the driver. The means of communication may
consist of a telephone, speaker tube, buzzer, pull cord, or other
mechanical or electrical device.

(e) Equipment. A sleeper berth must be properly equipped for
sleeping. Its equipment must include:

(1) Adequate bedclothing and blankets; and

(2) Either:

(i) Springs and a mattress; or

(ii) An innerspring mattress; or

(iii) A cellular rubber or flexible foam mattress at least four
inches thick; or

(iv) A mattress filled with a fluid and of sufficient thickness when
filled to prevent ``bottoming-out'' when occupied while the vehicle is
in motion.

(f) Ventilation. A sleeper berth must have louvers or other means of
providing adequate ventilation. A sleeper berth must be reasonably tight
against dust and rain.

(g) Protection against exhaust and fuel leaks and exhaust heat. A
sleeper berth must be located so that leaks in the vehicle's exhaust
system or fuel system do not permit fuel, fuel system gases, or exhaust
gases to enter the sleeper berth. A sleeper berth must be located so
that it will not be overheated or damaged by reason of its proximity to
the vehicle's exhaust system.

(h) Occupant restraint. A motor vehicle manufactured on or after
July 1, 1971, and equipped with a sleeper berth must be equipped with a
means of preventing ejection of the occupant of the sleeper berth during
deceleration of the vehicle. The restraint system must be designed,
installed, and maintained to withstand a minimum total force of 6,000
pounds applied toward the front of the vehicle and parallel to the
longitudinal axis of the vehicle.

Sec. 393.77 Heaters.

On every motor vehicle, every heater shall comply with the following
requirements:

(a) Prohibited types of heaters. The installation or use of the
following types of heaters is prohibited:

(1) Exhaust heaters. Any type of exhaust heater in which the engine
exhaust gases are conducted into or through any space occupied by
persons or any heater which conducts engine compartment air into any
such space.

(2) Unenclosed flame heaters. Any type of heater employing a flame
which is not fully enclosed, except that such heaters are not prohibited
when used for heating the cargo of tank motor vehicles.

(3) Heaters permitting fuel leakage. Any type of heater from the
burner of which there could be spillage or leakage of fuel upon the
tilting or overturning of the vehicle in which it is mounted.

(4) Heaters permitting air contamination. Any heater taking air,
heated or to be heated, from the engine compartment or from direct
contact with any portion of the exhaust system; or any heater taking air
in ducts from the outside atmosphere to be conveyed through the engine
compartment, unless said ducts are so constructed and installed as to
prevent contamination of the air so conveyed by exhaust or engine
compartment gases.

(5) Solid fuel heaters except wood charcoal. Any stove or other
heater employing solid fuel except wood charcoal.

(6) Portable heaters. Portable heaters shall not be used in any
space occupied by persons except the cargo space of motor vehicles which
are being loaded or unloaded.

(b) Heater specifications. All heaters shall comply with the
following specifications:

(1) Heating elements, protection. Every heater shall be so located
or protected as to prevent contact therewith by occupants, unless the
surface temperature of the protecting grilles or of any exposed portions
of the heaters, inclusive of exhaust stacks, pipes, or conduits shall be
lower than would cause contact burns. Adequate protection shall be
afforded against igniting parts of the vehicle or burning occupants by
direct radiation. Wood charcoal heaters shall be enclosed within a metal
barrel, drum, or similar protective enclosure which enclosure shall be
provided with a securely fastened cover.

(2) Moving parts, guards. Effective guards shall be provided for the
protection of passengers or occupants against injury by fans, belts, or
any other moving parts.

(3) Heaters, secured. Every heater and every heater enclosure shall
be securely fastened to the vehicle in a substantial manner so as to
provide against relative motion within the vehicle during normal usage
or in the event the vehicle overturns. Every heater shall be so
designed, constructed, and mounted as to minimize the likelihood of
disassembly of any of its parts, including exhaust stacks, pipes, or
conduits, upon overturn of the vehicle in or on which it is mounted.
Wood charcoal heaters shall be secured against relative motion within
the enclosure required by paragraph (c)(1) of this section, and the
enclosure shall be securely fastened to the motor vehicle.

(4) Relative motion between fuel tank and heater. When either in
normal operation or in the event of overturn, there is or is likely to
be relative motion between the fuel tank for a heater and the heater, or
between either of such units and the fuel lines between them, a suitable
means shall be provided at the point of greatest relative motion so as
to allow this motion without causing failure of the fuel lines.

(5) Operating controls to be protected. On every bus designed to
transport more than 15 passengers, including the driver, means shall be
provided to prevent unauthorized persons from tampering with the
operating controls. Such means may include remote control by the driver;
installation of controls at inaccessible places; control of adjustments
by key or keys; enclosure of controls in a locked space, locking of
controls, or other means of accomplishing this purpose.

(6) Heater hoses. Hoses for all hot water and steam heater systems
shall be specifically designed and constructed for that purpose.

(7) Electrical apparatus. Every heater employing any electrical
apparatus shall be equipped with electrical conductors, switches,
connectors, and other electrical parts of ample current-carrying
capacity to provide against overheating; any electric motor employed in
any heater shall be of adequate size and so located that it will not be
overheated; electrical circuits shall be provided with fuses and/or
circuit breakers to provide against electrical overloading; and all
electrical conductors employed in or leading to any heater shall be
secured against dangling, chafing, and rubbing and shall have suitable
protection against any other condition likely to produce short or open
circuits.

Note: Electrical parts certified as proper for use by Underwriters'
Laboratories, Inc., shall be deemed to comply with the foregoing
requirements.

(8) Storage battery caps. If a separate storage battery is located
within the personnel or cargo space, such battery shall be securely
mounted and equipped with nonspill filler caps.

(9) Combustion heater exhaust construction. Every heater employing
the combustion of oil, gas, liquefied petroleum gas, or any other
combustible material shall be provided with substantial means of
conducting the products of combustion to the outside of the vehicle:
Provided, however, That this requirement shall not apply to heaters used
solely to heat the cargo space of motor vehicles where such motor
vehicles or heaters are equipped with means specifically designed and
maintained so that the carbon monoxide concentration will never exceed
0.2 percent in the cargo space. The exhaust pipe, stack, or conduit if
required shall be sufficiently substantial and so secured as to provide
reasonable assurance against leakage or discharge of products of
combustion within the vehicle and, if necessary, shall be so insulated
as to make unlikely the burning or charring of parts of the vehicle by
radiation or by direct contact. The place of discharge of the products
of combustion to the atmosphere and the means of discharge of such
products shall be such as to minimize the likelihood of their reentry
into the vehicle under all operating conditions.

(10) Combustion chamber construction. The design and construction of
any combustion-type heater except cargo space heaters permitted by the
proviso of paragraph (c)(9) of this section and unenclosed flame heaters
used for heating cargo of tank motor vehicles shall be such as to
provide against the leakage of products of combustion into air to be
heated and circulated. The material employed in combustion chambers
shall be such as to provide against leakage because of corrosion,
oxidation, or other deterioration. Joints between combustion chambers
and the air chambers with which they are in thermal and mechanical
contact shall be so designed and constructed as to prevent leakage
between the chambers and the materials employed in such joints shall
have melting points substantially higher than the maximum temperatures
likely to be attained at the points of jointure.

(11) Heater fuel tank location. Every bus designed to transport more
than 15 passengers, including the driver, with heaters of the combustion
type shall have fuel tanks therefor located outside of and lower than
the passenger space. When necessary, suitable protection shall be
afforded by shielding or other means against the puncturing of any such
tank or its connections by flying stones or other objects.

(12) Heater, automatic fuel control. Gravity or siphon feed shall
not be permitted for heaters using liquid fuels. Heaters using liquid
fuels shall be equipped with automatic means for shutting off the fuel
or for reducing such flow of fuel to the smallest practicable magnitude,
in the event of overturn of the vehicle. Heaters using liquefied
petroleum gas as fuel shall have the fuel line equipped with automatic
means at the source of supply for shutting off the fuel in the event of
separation, breakage, or disconnection of any of the fuel lines between
the supply source and the heater.

(13) ``Tell-tale'' indicators. Heaters subject to paragraph (c)(14)
of this section and not provided with automatic controls shall be
provided with ``tell-tale'' means to indicate to the driver that the
heater is properly functioning. This requirement shall not apply to
heaters used solely for the cargo space in semitrailers or full
trailers.

(14) Shut-off control. Automatic means, or manual means if the
control is readily accessible to the driver without moving from the
driver's seat, shall be provided to shut off the fuel and electrical
supply in case of failure of the heater to function for any reason, or
in case the heater should function improperly or overheat. This
requirement shall not apply to wood charcoal heaters or to heaters used
solely to heat the contents of cargo tank motor vehicles, but wood
charcoal heaters must be provided with a controlled method of regulating
the flow of combustion air.

(15) Certification required. Every combustion-type heater, except
wood charcoal heaters, the date of manufacture of which is subsequent to
December 31, 1952, and every wood charcoal heater, the date of
manufacture of which is subsequent to September 1, 1953, shall be marked
plainly to indicate the type of service for which such heater is
designed and with a certification by the manufacturer that the heater
meets the applicable requirements for such use. For example, ``Meets I.C.C.
Bus Heater Requirements,'' Meets I.C.C. Flue-Vented Cargo Space Heater
Requirements,'' and after December 31, 1967, such certification shall
read ``Meets FMCSA Bus Heater Requirements,'' ``Meets FMCSA Flue-Vented
Cargo Space Heater Requirements,'' etc.

(i) Exception. The certification for a catalytic heater which is
used in transporting flammable liquid or gas shall be as prescribed
under Sec. 177.834(1) of this title.

Sec. 393.78 Windshield wipers.

(a) Every bus, truck, and truck tractor, having a windshield, shall
be equipped with at least two automatically-operating windshield wiper
blades, one on each side of the centerline of the windshield, for
cleaning rain, snow, or other moisture from the windshield and which
shall be in such condition as to provide clear vision for the driver,
unless one such blade be so arranged as to clean an area of the
windshield extending to within 1 inch of the limit of vision through the
windshield at each side: Provided, however, That in driveaway-towaway
operations this section shall apply only to the driven vehicle: And
provided further, That one windshield wiper blade will suffice under
this section when such driven vehicle in driveaway-towaway operation
constitutes part or all of the property being transported and has no
provision for two such blades.

(b) Every bus, truck, and truck tractor, the date of manufacture of
which is subsequent to June 30, 1953, which depends upon vacuum to
operate the windshield wipers, shall be so constructed that the
operation of the wipers will not be materially impaired by change in the
intake manifold pressure.

Sec. 393.79 Defrosting device.

Every bus, truck, and truck tractor having a windshield, when
operating under conditions such that ice, snow, or frost would be likely
to collect on the outside of the windshield or condensation on the
inside of the windshield, shall be equipped with a device or other
means, not manually operated, for preventing or removing such
obstructions to the driver's view: Provided, however, That this section
shall not apply in driveaway-towaway operations when the driven vehicle
is a part of the shipment being delivered.

Sec. 393.80 Rear-vision mirrors.

(a) Every bus, truck, and truck tractor shall be equipped with two
rear-vision mirrors, one at each side, firmly attached to the outside of
the motor vehicle, and so located as to reflect to the driver a view of
the highway to the rear, along both sides of the vehicle. All such
regulated rear-vision mirrors and their replacements shall meet, as a
minimum, the requirements of FMVSS No. 111 (49 CFR 571.111) in force at
the time the vehicle was manufactured.

(b) Exceptions. (1) Mirrors installed on a vehicle manufactured
prior to January 1, 1981, may be continued in service, provided that if
the mirrors are replaced they shall be replaced with mirrors meeting, as
a minimum, the requirements of FMVSS No. 111 (49 CFR 571.111) in force
at the time the vehicle was manufactured.

(2) Only one outside mirror shall be required, which shall be on the
driver's side, on trucks which are so constructed that the driver has a
view to the rear by means of an interior mirror.

(3) In driveway-towaway operations, the driven vehicle shall have at
least one mirror furnishing a clear view to the rear.

Sec. 393.81 Horn.

Every bus, truck, truck-tractor, and every driven motor vehicle in
driveaway-towaway operations shall be equipped with a horn and actuating
elements which shall be in such condition as to give an adequate and
reliable warning signal.

Sec. 393.82 Speedometer.

Every bus, truck, and truck-tractor shall be equipped with a
speedometer indicating vehicle speed in miles per hour, which shall be
operative with reasonable accuracy; however, this requirement shall not 
apply to any driven vehicle which is part of a shipment being delivered in a
driveaway-towaway operation if such driven vehicle is equipped with an
effective means of limiting its maximum speed to 45 miles per hour, nor
to any towed vehicle.

Sec. 393.83 Exhaust systems.

(a) Every motor vehicle having a device (other than as part of its
cargo) capable of expelling harmful combustion fumes shall have a system
to direct the discharge of such fumes. No part shall be located where
its location would likely result in burning, charring, or damaging the
electrical wiring, the fuel supply, or any combustible part of the motor
vehicle.

(b) No exhaust system shall discharge to the atmosphere at a
location immediately below the fuel tank or the fuel tank filler pipe.

(c) The exhaust system of a bus powered by a gasoline engine shall
discharge to the atmosphere at or within 6 inches forward of the
rearmost part of the bus.

(d) The exhaust system of a bus using fuels other than gasoline
shall discharge to the atmosphere either:

(1) At or within 15 inches forward of the rearmost part of the
vehicle; or

(2) To the rear of all doors or windows designed to be open, except
windows designed to be opened solely as emergency exits.

(e) The exhaust system of every truck and truck tractor shall
discharge to the atmosphere at a location to the rear of the cab or, if
the exhaust projects above the cab, at a location near the rear of the
cab.

(f) No part of the exhaust system shall be temporarily repaired with
wrap or patches.

(g) No part of the exhaust system shall leak or discharge at a point
forward of or directly below the driver/sleeper compartment. The exhaust
outlet may discharge above the cab/sleeper roofline.

(h) The exhaust system must be securely fastened to the vehicle.

(i) Exhaust systems may use hangers which permit required movement
due to expansion and contraction caused by heat of the exhaust and
relative motion between engine and chassis of a vehicle.

Sec. 393.84 Floors.

The flooring in all motor vehicles shall be substantially
constructed, free of unnecessary holes and openings, and shall be
maintained so as to minimize the entrance of fumes, exhaust gases, or
fire. Floors shall not be permeated with oil or other substances likely
to cause injury to persons using the floor as a traction surface.

Sec. 393.86 Rear impact guards and rear end protection.

(a)(1) General requirements for trailers and semitrailers
manufactured on or after January 26, 1998. Each trailer and semitrailer
with a gross vehicle weight rating of 4,536 kg (10,000 pounds) or more,
and manufactured on or after January 26, 1998, must be equipped with a
rear impact guard that meets the requirements of Federal Motor Vehicle
Safety Standard No. 223 (49 CFR 571.223) in effect at the time the
vehicle was manufactured. When the rear impact guard is installed on the
trailer or semitrailer, the vehicle must, at a minimum, meet the
requirements of FMVSS No. 224 (49 CFR 571.224) in effect at the time the
vehicle was manufactured. The requirements of paragraph (a) of this
section do not apply to pole trailers (as defined in Sec. 390.5 of this
chapter); pulpwood trailers, low chassis vehicles, special purpose
vehicles, wheels back vehicles (as defined in Sec. 393.5); and trailers
towed in driveaway-towaway operations (as defined in Sec. 390.5).

(2) Impact guard width. The outermost surfaces of the horizontal
member of the guard must extend to within 100 mm (4 inches) of the side
extremities of the vehicle. The outermost surface of the horizontal
member shall not extend beyond the side extremity of the vehicle.

(3) Guard height. The vertical distance between the bottom edge of
the horizontal member of the guard and the ground shall not exceed 
560 mm (22 inches) at any point across the
full width of the member. Guards with rounded corners may curve upward
within 255 mm (10 inches) of the longitudinal vertical planes that are
tangent to the side extremities of the vehicle.

(4) Guard rear surface. At any height 560 mm (22 inches) or more
above the ground, the rearmost surface of the horizontal member of the
guard must be within 305 mm (12 inches) of the rear extremity of the
vehicle. This paragraph shall not be construed to prohibit the rear
surface of the guard from extending beyond the rear extremity of the
vehicle. Guards with rounded corners may curve forward within 255 mm (10
inches) of the side extremity.

(5) Cross-sectional vertical height. The horizontal member of each
guard must have a cross sectional vertical height of at least 100 mm
(3.94 inches) at any point across the guard width.

(6) Certification and labeling requirements for rear impact
protection guards. Each rear impact guard used to satisfy the
requirements of paragraph (a)(1) of this section must be permanently
marked or labeled as required by FMVSS No. 223 (49 CFR 571.223, S5.3).
The label must be on the forward-facing surface of the horizontal member
of the guard, 305 mm (12 inches) inboard of the right end of the guard.
The certification label must contain the following information:

(i) The impact guard manufacturer's name and address;

(ii) The statement ``Manufactured in ----'' (inserting the month and
year that the guard was manufactured); and,

(iii) The letters ``DOT'', constituting a certification by the guard
manufacturer that the guard conforms to all requirements of FMVSS No.
223.

(b)(1) Requirements for motor vehicles manufactured after December
31, 1952 (except trailers or semitrailers manufactured on or after
January 26, 1998). Each motor vehicle manufactured after December 31,
1952, (except truck tractors, pole trailers, pulpwood trailers, or
vehicles in driveaway-towaway operations) in which the vertical distance
between the rear bottom edge of the body (or the chassis assembly if the
chassis is the rearmost part of the vehicle) and the ground is greater
than 76.2 cm (30 inches) when the motor vehicle is empty, shall be
equipped with a rear impact guard(s). The rear impact guard(s) must be
installed and maintained in such a manner that:

(i) The vertical distance between the bottom of the guard(s) and the
ground does not exceed 76.2 cm (30 inches) when the motor vehicle is
empty;

(ii) The maximum lateral distance between the closest points between
guards, if more than one is used, does not exceed 61 cm (24 inches);

(iii) The outermost surfaces of the horizontal member of the guard
are no more than 45.7 cm (18 inches) from each side extremity of the
motor vehicle;

(iv) The impact guard(s) are no more than 61 cm (24 inches) forward
of the rear extremity of the motor vehicle.

(2) Construction and attachment. The rear impact guard(s) must be
substantially constructed and attached by means of bolts, welding, or
other comparable means.

(3) Vehicle components and structures that may be used to satisfy
the requirements of paragraph (b) of this section. Low chassis vehicles,
special purpose vehicles, or wheels back vehicles constructed and
maintained so that the body, chassis, or other parts of the vehicle
provide the rear end protection comparable to impact guard(s) conforming
to the requirements of paragraph (b)(1) of this section shall be
considered to be in compliance with those requirements.

Sec. 393.87 Flags on projecting loads.

Any motor vehicle having a load or vehicle component which extends
beyond the sides more than 4 inches or more than 4 feet beyond the rear
shall have the extremities of the load marked with a red flag, not less
than 12 inches square, at each point where a lamp is required by Table
1, Sec. 393.11.

Sec. 393.88 Television receivers.

Any motor vehicle equipped with a television viewer, screen or other
means of visually receiving a television broadcast shall have the viewer
or screen located in the motor vehicle at a point to the rear of the back
of the driver's seat if such viewer or screen is in the same compartment
as the driver and the viewer or screen shall be so located as not to be
visible to the driver, while he/she is driving the motor vehicle. The
operating controls for the television receiver shall be so located that
the driver cannot operate them without leaving the driver's seat.

Sec. 393.89 Buses, driveshaft protection.

Any driveshaft extending lengthways under the floor of the passenger
compartment of a bus shall be protected by means of at least one guard
or bracket at that end of the shaft which is provided with a sliding
connection (spline or other such device) to prevent the whipping of the
shaft in the event of failure thereof or of any of its component parts.
A shaft contained within a torque tube shall not require any such
device.

Sec. 393.90 Buses, standee line or bar.

Except as provided below, every bus, which is designed and
constructed so as to allow standees, shall be plainly marked with a line
of contrasting color at least 2 inches wide or equipped with some other
means so as to indicate to any person that he/she is prohibited from
occupying a space forward of a perpendicular plane drawn through the
rear of the driver's seat and perpendicular to the longitudinal axis of
the bus. Every bus shall have clearly posted at or near the front, a
sign with letters at least one-half inch high stating that it is a
violation of the Federal Motor Carrier Safety Administration's
regulations for a bus to be operated with persons occupying the
prohibited area. The requirements of this section shall not apply to any
bus being transported in driveaway-towaway operation or to any level of
the bus other that the level in which the driver is located nor shall
they be construed to prohibit any seated person from occupying permanent
seats located in the prohibited area provided such seats are so located
that persons sitting therein will not interfere with the driver's safe
operation of the bus.

Sec. 393.91 Buses, aisle seats prohibited.

No bus shall be equipped with aisle seats unless such seats are so
designed and installed as to automatically fold and leave a clear aisle
when they are unoccupied. No bus shall be operated if any seat therein
is not securely fastened to the vehicle.

Sec. 393.92 Buses, marking emergency doors.

Any bus equipped with an emergency door shall have such door clearly
marked in letters at least 1 inch in height with the words ``Emergency
Door'' or ``Emergency Exit.'' Emergency doors shall also be identified
by a red electric lamp readily visible to passengers which lamp shall be
lighted at all times when lamps are required to be lighted by
Sec. 392.30.

Sec. 393.93 Seats, seat belt assemblies, and seat belt assembly anchorages.

(a) Buses--(1) Buses manufactured on or after January 1, 1965, and
before July 1, 1971. After June 30, 1972, every bus manufactured on or
after January 1, 1965, and before July 1, 1971, must be equipped with a
Type 1 or Type 2 seat belt assembly that conforms to Federal Motor
Vehicle Safety Standard No. 209 \1\ (Sec. 571.209) installed at the
driver's seat and seat belt assembly anchorages that conform to the
location and geometric requirements of Federal Motor Vehicle Safety
Standard No. 210 \1\ (Sec. 571.210) for that seat belt assembly.
---------------------------------------------------------------------------

\1\ Individual copies of Federal Motor Vehicle Safety Standards may
be obtained from the National Highway Traffic Safety Administration.
Nassif Building, 400 Seventh Street SW., Washington, D.C. 20590.
---------------------------------------------------------------------------

(2) Buses manufactured on or after July 1, 1971. Every bus
manufactured on or after July 1, 1971, must conform to the requirements
of Federal Motor Vehicle Safety Standard No. 208 \1\ (Sec. 571.208)
(relating to installation of seat belt assemblies) and Federal Motor
Vehicle Safety Standard No. 210 \1\ (Sec. 571.210) (relating to
installation of seat belt assembly anchorages).

(3) Buses manufactured on or after January 1, 1972. Every bus
manufactured on or after January 1, 1972, must conform to the
requirements of Federal Motor Vehicle Safety Standard 
No. 207 \1\ (Sec. 571.207) (relating to seating systems).

(b) Trucks and truck tractors--(1) Trucks and truck tractors
manufactured on and after January 1, 1965, and before July 1, 1971.
Except as provided in paragraph (d) of this section, after June 30,
1972, every truck and truck tractor manufactured on or after January 1,
1965, and before July 1, 1971, must be equipped with a Type 1 or Type 2
seat belt assembly that conforms to Federal Motor Vehicle Safety
Standard No. 209 (Sec. 571.209) installed at the driver's seat and at
the right front outboard seat, if the vehicle has one, and seat belt
assembly anchorages that conform to the location and geometric
requirements of Federal Motor Vehicle Safety Standard No. 210
(Sec. 571.210) for each seat belt assembly that is required by this
subparagraph.

(2) Trucks and truck tractors manufactured on or after July 1, 1971.
Every truck and truck tractor manufactured on or after July 1, 1971,
except a truck or truck tractor being transported in driveaway-towaway
operation and having an incomplete vehicle seating and cab
configuration, must conform to the requirements of Federal Motor Vehicle
Safety Standard No. 208 \1\ (Sec. 571.208) (relating to installation of
seat belt assemblies) and Federal Motor Vehicle Safety Standard No. 210
\1\ (Sec. 571.210) (relating to installation of seat belt assembly
anchorages).
---------------------------------------------------------------------------

\1\ See footnote to Sec. 393.93(a).
---------------------------------------------------------------------------

(3) Trucks and truck tractors manufactured on or after January 1,
1972. Every truck and truck tractor manufactured on or after January 1,
1972, except a truck or truck tractor being transported in driveaway-
towaway operation and having an incomplete vehicle seating and cab
configuration, must conform to the requirements of Federal Motor Vehicle
Safety Standard No. 207 \1\ (Sec. 571.207) (relating to seating
systems).

(c) Effective date of standards. Whenever paragraph (a) or (b) of
this section requires conformity to a Federal Motor Vehicle Safety
Standard, the vehicle or equipment must conform to the version of the
Standard that is in effect on the date the vehicle is manufactured or on
the date the vehicle is modified to conform to the requirements of
paragraph (a) or (b) of this section, whichever is later.

(d) Trucks and truck tractors manufactured on or after January 1,
1965, and before July 1, 1971, and operated in the State of Hawaii, must
comply with the provisions of paragraph (b) of this section on and after
January 1, 1976.

Sec. 393.94 Vehicle interior noise levels.

(a) Application of the rule in this section. Except as provided in
paragraph (d) of this section, this section applies to all motor
vehicles manufactured on and after October 1, 1974. On and after April
1, 1975, this section applies to all motor vehicles manufactured before
October 1, 1974.

(b) General rule. The interior sound level at the driver's seating
position of a motor vehicle must not exceed 90 dB(A) when measured in
accordance with paragraph (c) of this section.

(c) Test procedure. \2\ (1) Park the vehicle at a location so that
no large reflecting surfaces, such as other vehicles, signboards,
buildings, or hills, are within 50 feet of the driver's seating
position.
---------------------------------------------------------------------------

\2\ Standards of the American National Standards Institute are
published by the American National Standards Institute. Information and
copies may be obtained by writing to the Institute at 1430 Broadway, New
York, N.Y. 10018.
---------------------------------------------------------------------------

(2) Close all vehicle doors, windows, and vents. Turn off all power-
operated accessories.

(3) Place the driver in his/her normal seated position at the
vehicle's controls. Evacuate all occupants except the driver and the
person conducting the test.

(4) Use a sound level meter which meets the requirements of the
American National Standards Institute Standard ANSI S1.4-1971
Specification for Sound Level Meters, for Type 2 Meters. Set the meter
to the A-weighting network, ``fast'' meter response.

(5) Locate the microphone, oriented vertically upward, 6 inches to
the right of, in the same plane as, and directly in line with, the driver's right
ear.

(6) With the vehicle's transmission in neutral gear, accelerate its
engine to either its maximum governed engine speed, if it is equipped
with an engine governor, or its speed at its maximum rated horsepower,
if it is not equipped with an engine governor. Stabilize the engine at
that speed.

(7) Observe the A-weighted sound level reading on the meter for the
stabilized engine speed condition. Record that reading, if the reading
has not been influenced by extraneous noise sources such as motor
vehicles operating on adjacent roadways.

(8) Return the vehicle's engine speed to idle and repeat the
procedures specified in paragraphs (c) (6) and (7) of this section until
two maximum sound levels within 2 dB of each other are recorded.
Numerically average those two maximum sound level readings.

(9) The average obtained in accordance with paragraph (c)(8) of this
section is the vehicle's interior sound level at the driver's seating
position for the purpose of determining whether the vehicle conforms to
the rule in paragraph (b) of this section. However, a 2 dB tolerance
over the sound level limitation specified in that paragraph is permitted
to allow for variations in test conditions and variations in the
capabilities of meters.

(10) If the motor vehicle's engine radiator fan drive is equipped
with a clutch or similar device that automatically either reduces the
rotational speed of the fan or completely disengages the fan from its
power source in response to reduced engine cooling loads the vehicle may
be parked before testing with its engine running at high idle or any
other speed the operator may choose, for sufficient time but not more
than 10 minutes, to permit the engine radiator fan to automatically
disengage.

(d) Vehicles manufactured before October 1, 1974, and operated
wholly within the State of Hawaii, need not comply with this section
until April 1, 1976.

Sec. 393.94 Vehicle interior noise levels.

(a) Application of the rule in this section. Except as provided in
paragraph (d) of this section, this section applies to all motor
vehicles manufactured on and after October 1, 1974. On and after April
1, 1975, this section applies to all motor vehicles manufactured before
October 1, 1974.

(b) General rule. The interior sound level at the driver's seating
position of a motor vehicle must not exceed 90 dB(A) when measured in
accordance with paragraph (c) of this section.

(c) Test procedure. \2\ (1) Park the vehicle at a location so that
no large reflecting surfaces, such as other vehicles, signboards,
buildings, or hills, are within 50 feet of the driver's seating
position.

---------------------------------------------------------------------------

\2\ Standards of the American National Standards Institute are published by the American National Standards Institute. Information and copies may be obtained by writing to the Institute at 1430 Broadway, New York, N.Y. 10018. ---------------------------------------------------------------------------

(2) Close all vehicle doors, windows, and vents. Turn off all power-
operated accessories.

(3) Place the driver in his/her normal seated position at the
vehicle's controls. Evacuate all occupants except the driver and the
person conducting the test.

(4) Use a sound level meter which meets the requirements of the
American National Standards Institute Standard ANSI S1.4-1971
Specification for Sound Level Meters, for Type 2 Meters. Set the meter
to the A-weighting network, ``fast'' meter response.

(5) Locate the microphone, oriented vertically upward, 6 inches to
the right of, in the same plane as, and directly in line with, the driver's right
ear.

(6) With the vehicle's transmission in neutral gear, accelerate its
engine to either its maximum governed engine speed, if it is equipped
with an engine governor, or its speed at its maximum rated horsepower,
if it is not equipped with an engine governor. Stabilize the engine at
that speed.

(7) Observe the A-weighted sound level reading on the meter for the
stabilized engine speed condition. Record that reading, if the reading
has not been influenced by extraneous noise sources such as motor
vehicles operating on adjacent roadways.

(8) Return the vehicle's engine speed to idle and repeat the
procedures specified in paragraphs (c) (6) and (7) of this section until
two maximum sound levels within 2 dB of each other are recorded.
Numerically average those two maximum sound level readings.

(9) The average obtained in accordance with paragraph (c)(8) of this
section is the vehicle's interior sound level at the driver's seating
position for the purpose of determining whether the vehicle conforms to
the rule in paragraph (b) of this section. However, a 2 dB tolerance
over the sound level limitation specified in that paragraph is permitted
to allow for variations in test conditions and variations in the
capabilities of meters.

(10) If the motor vehicle's engine radiator fan drive is equipped
with a clutch or similar device that automatically either reduces the
rotational speed of the fan or completely disengages the fan from its
power source in response to reduced engine cooling loads the vehicle may
be parked before testing with its engine running at high idle or any
other speed the operator may choose, for sufficient time but not more
than 10 minutes, to permit the engine radiator fan to automatically
disengage.

(d) Vehicles manufactured before October 1, 1974, and operated
wholly within the State of Hawaii, need not comply with this section
until April 1, 1976.

Sec. 393.95 Emergency equipment on all power units.

Except for a lightweight vehicle, every bus, truck, truck-tractor,
and every driven vehicle in driveaway-towaway operation must be equipped
as follows:

(a) Fire extinguisher. (1) Except as provided in paragraph (a)(4) of
this section, every power unit must be equipped with a fire extinguisher
that is properly filled and located so that it is readily accessible for
use. The fire extinguisher must be securely mounted on the vehicle. The
fire extinguisher must be designed, constructed, and maintained to
permit visual determination of whether it is fully charged. The fire
extinguisher must have an extinguishing agent that does not need
protection from freezing. The fire extinguisher must not use a
vaporizing liquid that gives off vapors more toxic than those produced
by the substances shown as having a toxicity rating of 5 or 6 in the
Underwriters' Laboratories ``Classification of Comparative Life Hazard
of Gases and Vapors.'' \1\
---------------------------------------------------------------------------

\1\ Copies of the Classification can be obtained by writing to
Underwriters' Laboratories, Inc., 205 East Ohio Street, Chicago, Ill.
60611.
---------------------------------------------------------------------------

(2)(i) Before July 1, 1971, a power unit that is used to transport
hazardous materials must be equipped with a fire extinguisher having an
Underwriters' Laboratories rating \2\ of 4 B:C or more. On and after
July 1, 1971, a power unit that is used to transport hazardous materials
must be equipped with a fire extinguisher having an Underwriters'
Laboratories rating \2\ of 10 B:C or more.
---------------------------------------------------------------------------

\2\ Underwriters' Laboratories ratings are given to fire
entinguishers under the standards of Underwriters' Laboratories, Inc.,
205 East Ohio Street, Chicago, Ill. 60611. Extinguishers must conform to
the standards in effect on the date of manufacture or on Jan. 1, 1969,
whichever is earlier.
---------------------------------------------------------------------------

(ii) Before January 1, 1973, a power unit that is not used to
transport hazardous materials must be equipped with a fire extinguisher
having an Underwriters' Laboratories rating \2\ of 4 B:C or more. On and
after January 1, 1973, a power unit that is not used to transport hazardous
materials must be equipped with either--

(A) A fire extinguisher having an Underwriters' Laboratories rating
\2\ of 5 B:C or more; or

(B) Two fire extinguishers, each of which has an Underwriters'
Laboratories rating \2\ of 4 B:C or more.

(iii) Each fire extinguisher required by this subparagraph must be
labeled or marked with its Underwriters' Laboratories rating \2\ and
must meet the requirements of paragraph (a)(1) of this section.

(3) For purposes of this paragraph, a power unit is used to
transport hazardous materials only if the power unit or a motor vehicle
towed by the power unit must be marked or placarded in accordance with
Sec. 177.823 of this title.

(4) This paragraph does not apply to the driven unit in a driveaway-
towaway operation.

(b) [Reserved]

(c) Spare fuses. At least one spare fuse or other overload
protective device, if the devices used are not of a reset type, for each
kind and size used. In driveaway-towaway operations, spares located on
any one of the vehicles will be deemed adequate.

(d)-(e) [Reserved]

(f) Warning devices for stopped vehicles. Except as provided in
paragraph (g) of this section, one of the following combinations of
warning devices:

(1) Vehicles equipped with warning devices before January 1, 1974.
Warning devices specified below may be used until replacements are
necessary:

(i) Three liquid-burning emergency flares which satisfy the
requirements of SAE Standard J597, ``Liquid Burning Emergency Flares,''
and three fusees and two red flags; or

(ii) Three electric emergency lanterns which satisfy the
requirements of SAE Standard J596, ``Electric Emergency Lanterns,'' and
two red flags; or

(iii) Three red emergency reflectors which satisfy the requirements
of paragraph (i) of this section, and two red flags; or

(iv) Three red emergency reflective triangles which satisfy the
requirements of paragraph (h) of this section; or

(v) Three bidirectional emergency reflective triangles that conform
to the requirements of Federal Motor Vehicle Safety Standard No. 125,
Sec. 571.125 of this title.

(2) Vehicles equipped with warning devices on and after January 1,
1974. (i) Three bidirectional emergency reflective triangles that
conform to the requirements of Federal Motor Vehicle Safety Standard No.
125, Sec. 571.125 of this title; or

(ii) At least 6 fusees or 3 liquid-burning flares. The vehicle must
have as many additional fusees or liquid-burning flares as are necessary
to satisfy the requirements of Sec. 392.22.

(3) Supplemental warning devices. Other warning devices may be used
in addition to, but not in lieu of, the required warning devices,
provided those warning devices do not decrease the effectiveness of the
required warning devices.

(g) Restrictions on the use of flame-producing devices. Liquid-
burning flares, fusees, oil lanterns, or any signal produced by a flame
shall not be carried on any commercial motor vehicle transporting
Division 1.1, 1.2, 1.3 (explosives) hazardous materials; any cargo tank
motor vehicle used for the transportation of Division 2.1 (flammable
gas) or Class 3 (flammable liquid) hazardous materials whether loaded or
empty; or any commercial motor vehicle using compressed gas as a motor
fuel.

(h) Requirements for emergency reflective triangles manufactured
before January 1, 1974. (1) Each reflector shall be a collapsible
equilateral triangle, with legs not less than 17 inches long and not
less than 2 inches wide. The front and back of the exposed leg surfaces
shall be covered with red reflective material not less than one half
inch in width. The reflective surface, front and back, shall be
approximately parallel. When placed in position, one point of the
triangle shall be upward. The area within the sides of the triangle
shall be open.

(2) Reflective material: The reflecting material covering the leg of
the equilateral triangle shall comply either with:

(i) The requirements for reflex-reflector elements made of red
methyl-methacrylate plastic material, meeting the color, sealing,
minimum candle-power, wind test, vibration test, and corrosion resistance
test of section 3and 4 of Federal Specification RR-R-1185, dated 
November 17, 1966, or

(ii) The requirements for red reflective sheeting of Federal
Specification L-S-300, dated September 7, 1965, except that the
aggregate candlepower of the assembled triangle, in one direction, shall
be not less than eight when measured at 0.2[deg] divergence angle and -
4[deg] incidence angle, and not less than 80 percent of the candlepower
specified for 1 square foot of material at all other angles shown in
Table II, Reflective Intensity Values, of L-S-300.

(3) Reflective surfaces alignment: Every reflective triangle shall
be so constructed that, when the triangle is properly placed, the
reflective surfaces shall be in a plane perpendicular to the plane of
the roadway surface with a permissible tolerance of [plusmn]10[deg].
Reflective triangles which are collapsible shall be provided with means
for holding the reflective surfaces within the required tolerance. Such
holding means shall be readily capable of adjustment without the use of
tools or special equipment.

(4) Reflectors mechanical adequacy: Every reflective triangle shall
be of such weight and dimensions as to remain stationary when subjected
to a 40 mile per hour wind when properly placed on any clean, dry paved
road surface. The reflective triangle shall be so constructed as to
withstand reasonable shocks without breakage.

(5) Reflectors, incorporation in holding device: Each set of
reflective triangles shall be adequately protected by enclosure in a
box, rack, or other adequate container specially designed and
constructed so that the reflectors may be readily extracted for use.

(6) Certification: Every red emergency reflective triangle designed
and constructed to comply with these requirements shall be plainly
marked with the certification of the manufacturer that it complies
therewith.

(i) Requirements for red emergency reflectors. Each red emergency
reflector shall conform in all respects to the following requirements:

(1) Reflecting elements required. Each reflector shall be composed
of at least two reflecting elements or surfaces on each side, front and
back. The reflecting elements, front and back, shall be approximately
parallel.

(2) Reflecting elements to be Class A. Each reflecting element or
surface shall meet the requirement for a red Class A reflector contained
in the SAE Recommended Practice \1\ ``Reflex Reflectors.'' The aggregate
candlepower output of all the reflecting elements or surface in one
direction shall not be less than 12 when tested in a perpendicular
position with observation at one-third degree as specified in the
Photometric Test contained in the above-mentioned Recommended Practice.
---------------------------------------------------------------------------

\1\ See footnote 1 to Sec. 393.24(c).
---------------------------------------------------------------------------

(3) Reflecting surfaces, protection. If the reflector or the
reflecting elements are so designed or constructed that the reflecting
surfaces would be adversely affected by dust, soot, or other foreign
matter or contacts with other parts of the reflector or its container,
then such reflecting surfaces shall be adequately sealed within the body
of the reflector.

(4) Reflecting surfaces to be perpendicular. Every reflector shall
be so constructed that, when the reflector is properly placed, every
reflecting element or surface is in a plane perpendicular to the plane
of the roadway surface. Reflectors which are collapsible shall be
provided with means for locking the reflector elements or surfaces in
the required position; such locking means shall be readily capable of
adjustment without the use of tools or special equipment.

(5) Reflectors, mechanical adequacy. Every reflector shall be of
such weight and dimensions as to remain stationary when subjected to a
40 mile per hour wind when properly placed on any clean, dry, paved road
surface. The reflector shall be so constructed as to withstand
reasonable shocks without breakage.

(6) Reflectors, incorporation on holding device. Each set of
reflectors and the reflecting elements or surfaces incorporated therein
shall be adequately protected by enclosure in a box, rack, or other
adequate container specially designed and constructed so that the
reflectors may be readily extracted for use.

(7) Certification. Every red emergency reflector designed and
constructed to comply with these requirements shall be plainly marked
with the certification of the manufacturer that it complies therewith.

(j) Requirements for fusees and liquid-burning flares. Each fusee
shall be capable of burning for 30 minutes, and each liquid-burning
flare shall contain enough fuel to burn continuously for at least 60
minutes. Fusees and liquid-burning flares shall conform to the
requirements of Underwriters Laboratories, Inc., UL No. 912, Highway
Emergency Signals, Fourth Edition, July 30, 1979, (with an amendment
dated November 9, 1981). (See Sec. 393.7(c) for information on the
incorporation by reference and availability of this document.) Each
fusee and liquid-burning flare shall be marked with the UL symbol in
accordance with the requirements of UL 912.

(k) Requirements for red flags. Red flags shall be not less than 12
inches square, with standards adequate to maintain the flags in an
upright position.

Sec. 393.100 Which types of commercial motor vehicles are subject to the cargo securement standards of this subpart, and what general requirements apply?

Source: 67 FR 61225, Sept. 27, 2002, unless otherwise noted.

(a) Applicability. The rules in this subpart are applicable to
trucks, truck tractors, semitrailers, full trailers, and pole trailers.

(b) Prevention against loss of load. Each commercial motor vehicle
must, when transporting cargo on public roads, be loaded and equipped,
and the cargo secured, in accordance with this subpart to prevent the
cargo from leaking, spilling, blowing or falling from the motor vehicle.

(c) Prevention against shifting of load. Cargo must be contained,
immobilized or secured in accordance with this subpart to prevent
shifting upon or within the vehicle to such an extent that the vehicle's
stability or maneuverability is adversely affected.

Sec. 393.102 What are the minimum performance criteria for cargo securement devices and systems?

(a) Performance criteria. Cargo securement devices and systems must
be capable of withstanding the following three forces, applied
separately:

(1) 0.8 g deceleration in the forward direction;

(2) 0.5 g acceleration in the rearward direction; and

(3) 0.5 g acceleration in a lateral direction.

(b) Performance criteria for devices to prevent vertical movement of
loads that are not contained within the structure of the vehicle.
Securement systems must provide a downward force equivalent to at least
20 percent of the weight of the article of cargo if the article is not
fully contained within the structure of the vehicle. If the article is
fully contained within the structure of the vehicle, it may be secured
in accordance with Sec. 393.106(b).

(c) Prohibition on exceeding working load limits. Cargo securement
devices and systems must be designed, installed, and maintained to
ensure that the maximum forces acting on the devices or systems do not
exceed the working load limit for the devices under the conditions
listed in paragraphs (a) and (b) of this section.

(d) Equivalent means of securement. Cargo that is immobilized, or
secured in accordance with the applicable requirements of Secs. 393.104
through 393.136, is considered as meeting the performance criteria of
this section.

Sec. 393.104 What standards must cargo securement devices and systems meet in order to satisfy the requirements of this subpart?

(a) General. All devices and systems used to secure cargo to or
within a vehicle must be capable of meeting the requirements of
Sec. 393.102.
(b) Prohibition on the use of damaged securement devices. All
vehicle structures, systems, parts, and components used to secure cargo
must be in proper working order when used to perform that function with
no damaged or weakened components that will adversely effect their
performance for cargo securement purposes, including reducing the
working load limit, and must not have any cracks or cuts.
(c) Vehicle structures and anchor points. Vehicle structures,
floors, walls, decks, tiedown anchor points, headerboards, bulkheads,
stakes, posts and associated mounting pockets used to contain or secure
articles of cargo must be strong enough to meet the performance criteria
of Sec. 393.102, with no damaged or weakened components that will
adversely effect their performance for cargo securement purposes,
including reducing the working load limit, and must not have any cracks
or cuts.
(d) Material for dunnage, chocks, cradles, shoring bars, blocking
and bracing. Material used as dunnage or dunnage bags, chocks, cradles,
shoring bars, or used for blocking and bracing, must not have damage or
defects which would compromise the effectiveness of the securement
system.
(e) Manufacturing standards for tiedown assemblies. Tiedown
assemblies (including chains, wire rope, steel strapping, synthetic
webbing, and cordage) and other attachment or fastening devices used to
secure articles of cargo to, or in, commercial motor vehicles must
conform to the following applicable standards:

\1\ Steel strapping not marked by the manufacturer with a working load limit will be considered to have a working load limit equal to one-fourth of the breaking strength listed in ASTM D3953-97.

\2\ Steel strapping 25.4 mm (1 inch) or wider must have at least two pairs of crimps in each seal and, when an end-over-end lap joint is formed, must be sealed with at least two seals.

\3\ Wire rope which is not marked by the manufacturer with a working load limit shall be considered to have a working load limit equal to one-fourth of the nominal strength listed in the manual.

\4\ See Sec. 393.7 for information on the incorporation by reference and availability of this document.

(f) Use of tiedowns. (1) Tiedowns and securing devices must not
contain knots.

(2) If a tiedown is repaired, it must be repaired in accordance with
the applicable standards in paragraph (e) of this section, or the
manufacturer's instructions.

(3) Each tiedown must be attached and secured in a manner that
prevents it from becoming loose, unfastening, opening or releasing while
the vehicle is in transit.

(4) All tiedowns and other components of a cargo securement system
used to secure loads on a trailer equipped with rub rails, must be
located inboard of the rub rails whenever practicable.

(5) Edge protection must be used whenever a tiedown would be subject
to abrasion or cutting at the point where it touches an article of
cargo. The edge protection must resist abrasion, cutting and crushing.

Sec. 393.106 What are the general requirements for securing articles of cargo?

(a) Applicability. The rules in this section are applicable to the
transportation of all types of articles of cargo, except commodities in
bulk that lack structure or fixed shape (e.g., liquids, gases, grain,
liquid concrete, sand, gravel, aggregates) and are transported in a
tank, hopper, box or similar device that forms part of the structure of
a commercial motor vehicle. The rules in this section apply to the cargo
types covered by the commodity-specific rules of Sec. 393.116 through
Sec. 393.136. The commodity-specific rules take precedence over the
general requirements of this section when additional requirements are
given for a commodity listed in those sections.

(b) General. Cargo must be firmly immobilized or secured on or
within a vehicle by structures of adequate strength, dunnage or dunnage
bags, shoring bars, tiedowns or a combination of these.

(c) Cargo placement and restraint. (1) Articles of cargo that are
likely to roll must be restrained by chocks, wedges, a cradle or other
equivalent means to prevent rolling. The means of preventing rolling
must not be capable of becoming unintentionally unfastened or loose
while the vehicle is in transit.

(2) Articles or cargo placed beside each other and secured by
transverse tiedowns must either:

(i) Be placed in direct contact with each other, or

(ii) Be prevented from shifting towards each other while in transit.

(d) Minimum strength of cargo securement devices and systems. The
aggregate working load limit of any securement system used to secure an
article or group of articles against movement must be at least one-half
times the weight of the article or group of articles. The aggregate
working load limit is the sum of:

(1) One-half of the working load limit of each associated connector
or attachment mechanism used to secure a part of the article of cargo to
the vehicle; and

(2) One-half of the working load limit for each end section of a
tiedown that is attached to an anchor point.

Sec. 393.108 How is the working load limit of a tiedown determined?

(a) The working load limit (WLL) of a tiedown, associated connector
or attachment mechanism is the lowest working load limit of any of its
components (including tensioner), or the working load limit of the
anchor points to which it is attached, whichever is less.

(b) The working load limits of tiedowns may be determined by using
either the tiedown manufacturer's markings or by using the tables in
this section. The working load limits listed in the tables are to be
used when the tiedown material is not marked by the manufacturer with
the working load limit. Tiedown materials which are marked by the
manufacturer with working load limits that differ from the tables, shall
be considered to have a working load limit equal to the value for which
they are marked.

(c) Synthetic cordage (e.g., nylon, polypropylene, polyester) which
is not marked or labeled to enable identification of its composition or
working load limit shall be considered to have a working load limit 
equal to that for polypropylene fiber rope.

(d) Welded steel chain which is not marked or labeled to enable
identification of its grade or working load limit shall be considered to
have a working load limit equal to that for grade 30 proof coil chain.

(e)(1) Wire rope which is not marked by the manufacturer with a
working load limit shall be considered to have a working load limit
equal to one-fourth of the nominal strength listed in the Wire Rope
Users Manual.

(2) Wire which is not marked or labeled to enable identification of
its construction type shall be considered to have a working load limit
equal to that for 6 x 37, fiber core wire rope.

(f) Manila rope which is not marked by the manufacturer with a
working load limit shall be considered to have a working load limit
based on its diameter as provided in the tables of working load limits.

(g) Friction mats which are not marked or rated by the manufacturer
shall be considered to provide resistance to horizontal movement equal
to 50 percent of the weight placed on the mat.

Sec. 393.110 What else do I have to do to determine the minimum number of tiedowns?

(a) In addition to the requirements of Sec. 393.106, the minimum
number of tiedowns required to secure an article or group of articles
against movement depends on the length of the article(s) being secured,
and the requirements of paragraphs (b) and (c) of this section.

(b) When an article is not blocked or positioned to prevent movement
in the forward direction by a headerboard, bulkhead, other cargo that is
positioned to prevent movement, or other appropriate blocking devices,
it must be secured by at least:

(1) One tiedown for articles 5 feet (1.52 meters) or less in length,
and 1,100 pounds (500 kg) or less in weight;

(2) Two tiedowns if the article is:

(i) 5 feet (1.52 meters) or less in length and more than 1,100
pounds (500 kg) in weight; or

(ii) Longer than 5 feet (1.52 meters) but less than or equal to 10
feet (3.04 meters) in length, irrespective of the weight.

(3) Two tiedowns if the article is longer than 10 feet (3.04
meters), and one additional tiedown for every 10 feet (3.04 meters) of
article length, or fraction thereof, beyond the first 10 feet (3.04
meters) of length.

(c) If an individual article is required to be blocked, braced or
immobilized to prevent movement in the forward direction by a
headerboard, bulkhead, other articles which are adequately secured or by
an appropriate blocking or immobilization method, it must be secured by
at least one tiedown for every 3.04 meters (10 feet) or article length,
or fraction thereof.

(d) Special rule for special purpose vehicles. The rules in this
section do not apply to a vehicle transporting one or more articles of
cargo such as, but not limited to, machinery or fabricated structural
items (e.g., steel or concrete beams, crane booms, girders, and trusses,
etc.) which, because of their design, size, shape, or weight, must be
fastened by special methods. However, any article of cargo carried on
that vehicle must be securely and adequately fastened to the vehicle.

Sec. 393.112 Must a tiedown be adjustable?

Each tiedown, or its associated connectors, or its attachment
mechanisms must be designed, constructed, and maintained so the driver
of an in-transit commercial motor vehicle can tighten them. However,
this requirement does not apply to the use of steel strapping.

Sec. 393.114 What are the requirements for front end structures used as part of a cargo securement system?

(a) Applicability. The rules in this section are applicable to
commercial motor vehicles transporting articles of cargo that are in
contact with the front end structure of the vehicle. The front end
structure on these cargo-carrying vehicles must meet the performance
requirements of this section.

(b) Height and width. (1) The front end structure must extend either
to a height of 4 feet above the floor of the vehicle or to a height at
which it blocks forward movement of any item of article of cargo being
carried on the vehicle, whichever is lower.

(2) The front end structure must have a width which is at least
equal to the width of the vehicle or which blocks forward movement of
any article of cargo being transported on the vehicle, whichever is
narrower.

(c) Strength. The front end structure must be capable of
withstanding the following horizontal forward static load:

(1) For a front end structure less than 6 feet in height, a
horizontal forward static load equal to one-half (0.5) of the weight of
the articles of cargo being transported on the vehicle uniformly
distributed over the entire portion of the front end structure that is
within 4 feet above the vehicle's floor or that is at or below a height
above the vehicle's floor at which it blocks forward movement of any
article of the vehicle's cargo, whichever is less; or

(2) For a front end structure 6 feet in height or higher, a
horizontal forward static load equal to four-tenths (0.4) of the weight
of the articles of cargo being transported on the vehicle uniformly
distributed over the entire front end structure.

(d) Penetration resistance. The front end structure must be
designed, constructed, and maintained so that it is capable of resisting
penetration by any article of cargo that contacts it when the vehicle
decelerates at a rate of 20 feet per second, per second. The front end
structure must have no aperture large enough to permit any article of
cargo in contact with the structure to pass through it.

(e) Substitute devices. The requirements of this section may be met
by the use of devices performing the same functions as a front end
structure, if the devices are at least as strong as, and provide
protection against shifting articles of cargo at least equal to, a front
end structure which conforms to those requirements.

Sec. 393.116 What are the rules for securing logs?

(a) Applicability. The rules in this section are applicable to the
transportation of logs with the following exceptions:

(1) Logs that are unitized by banding or other comparable means may
be transported in accordance with the general cargo securement rules of
Secs. 393.100 through 393.114.

(2) Loads that consist of no more than four processed logs may be
transported in accordance with the general cargo securement rules of
Secs. 393.100 through 393.114.

(3) Firewood, stumps, log debris and other such short logs must be
transported in a vehicle or container enclosed on both sides, front, and
rear and of adequate strength to contain them. Longer logs may also be
so loaded.

(b) Components of a securement system. (1) Logs must be transported
on a vehicle designed and built, or adapted, for the transportation of
logs. Any such vehicle must be fitted with bunks, bolsters, stakes or
standards, or other equivalent means, that cradle the logs and prevent
them from rolling.

(2) All vehicle components involved in securement of logs must be
designed and built to withstand all anticipated operational forces
without failure, accidental release or permanent deformation. Stakes or
standards that are not permanently attached to the vehicle must be
secured in a manner that prevents unintentional separation from the
vehicle in transit.

(3) Tiedowns must be used in combination with the stabilization
provided by bunks, stakes and bolsters to secure the load.

(c) Use of securement system. (1) Logs must be solidly packed, and
the outer bottom logs must be in contact with and resting solidly
against the bunks, bolsters, stakes or standards.

(2) Each outside log on the side of a stack of logs must touch at
least two stakes, bunks, bolsters, or standards. If one end does not
actually touch a stake, it must rest on other logs in a stable manner
and must extend beyond the stake, bunk, bolster or standard.

(3) The center of the highest outside log on each side or end must
be below the top of each stake, bunk or standard.

(4) Each log that is not held in place by contact with other logs or
the stakes, bunks, or standards must be held in place by a tiedown.
Additional tiedowns or securement devices must be used when the
condition of the wood results in such low friction between logs that
they are likely to slip upon each other.

(d) Securement of shortwood logs loaded crosswise on frame, rail and
flatbed vehicles. In addition to the requirements of paragraphs (b) and
(c) of this section, each stack of logs loaded crosswise must meet the
following rules:

(1) In no case may the end of a log in the lower tier extend more
than one-third of the log's total length beyond the nearest supporting
structure on the vehicle.

(2) When only one stack of shortwood is loaded crosswise, it must be
secured with at least two tiedowns. The tiedowns must attach to the
vehicle frame at the front and rear of the load, and must cross the load
in this direction.

(3) When two tiedowns are used, they must be positioned at
approximately one-third and two-thirds of the length of the logs.

(4) A vehicle that is more than 10 meters (33 feet) long must be
equipped with center stakes, or comparable devices, to divide it into
sections approximately equal in length. Where a vehicle is so divided,
each tiedown must secure the highest log on each side of the center
stake, and must be fastened below these logs. It may be fixed at each
end and tensioned from the middle, or fixed in the middle and tensioned
from each end, or it may pass through a pulley or equivalent device in
the middle and be tensioned from one end.

(5) Any structure or stake that is subjected to an upward force when
the tiedowns are tensioned must be anchored to resist that force.

(6) If two stacks of shortwood are loaded side-by-side, in addition
to meeting the requirements of paragraphs (d)(1) through (d)(5) of this
section, they must be loaded so that:

(i) There is no space between the two stacks of logs;

(ii) The outside of each stack is raised at least 2.5 cm (1 in)
within 10 cm (4 in) of the end of the logs or the side of the vehicle;

(iii) The highest log is no more than 2.44 m (8 ft) above the deck;
and

(iv) At least one tiedown is used lengthwise across each stack of
logs.

(e) Securement of logs loaded lengthwise on flatbed and frame
vehicles. In addition to meeting the requirements of paragraphs (b) and
(c) of this section, each stack of shortwood loaded lengthwise on a
frame vehicle or on a flatbed must be secured to the vehicle by at least
two tiedowns.

(f) Securement of logs transported on pole trailers. (1) The load
must be secured by at least one tiedown at each bunk, or alternatively,
by at least two tiedowns used as wrappers that encircle the entire load
at locations along the load that provide effective securement.

(2) The front and rear wrappers must be at least 3.04 meters (10
feet) apart.

(3) Large diameter single and double log loads must be immobilized
with chock blocks or other equivalent means to prevent shifting.

(4) Large diameter logs that rise above bunks must be secured to the
underlying load with at least two additional wrappers.

Sec. 393.118 What are the rules for securing dressed lumber or similar building products?

(a) Applicability. The rules in this section apply to the
transportation of bundles of dressed lumber, packaged lumber, building
products such as plywood, gypsum board or other materials of similar
shape. Lumber or building products which are not bundled or packaged
must be treated as loose items and transported in accordance with
Secs. 393.100 through 393.114 of this subpart. For the purpose of this
section, ``bundle'' refers to packages of lumber, building materials or
similar products which are unitized for securement as a single article
of cargo.

(b) Positioning of bundles. Bundles must be placed side by side in
direct contact with each other, or a means must be provided to prevent
bundles from shifting towards each other.

(c) Securement of bundles transported using no more than one tier.
Bundles carried on one tier must be secured in accordance with the
general provisions of Secs. 393.100 through 393.114.

(d) Securement of bundles transported using more than one tier.
Bundles carried in more than one tier must be either:

(1) Blocked against lateral movement by stakes on the sides of the
vehicle and secured by tiedowns laid out over the top tier, as outlined 
in the general provisions of Secs. 393.100 through 393.114; or

(2) Restrained from lateral movement by blocking or high friction
devices between tiers and secured by tiedowns laid out over the top
tier, as outlined in the general provisions of Secs. 393.100 through
393.114; or

(3) Placed directly on top of other bundles or on spacers and
secured in accordance with the following:

(i) The length of spacers between bundles must provide support to
all pieces in the bottom row of the bundle.

(ii) The width of individual spacers must be equal to or greater
than the height.

(iii) If spacers are comprised of layers of material, the layers
must be unitized or fastened together in a manner which ensures that the
spacer performs as a single piece of material.

(iv) The arrangement of the tiedowns for the bundles must be:

(A) Secured by tiedowns over the top tier of bundles, in accordance
with the general provisions of Secs. 393.100 through 393.114 with a
minimum of two tiedowns for bundles longer than 1.52 meters (5 ft); and

(B) Secured by tiedowns in accordance with the general provisions of
Secs. 393.100 through 393.114 over the second tier or over a middle tier
of a maximum height of 1.85 meters (6 ft) above the trailer deck,
whichever is greater, for each stack of bundles composed of more than
two tiers; or

(4) Secured by tiedowns over each tier of bundles, in accordance
with Secs. 393.100 through 393.114 using a minimum of two tiedowns over
each of the top bundles longer than 1.52 meters (5 ft), in all
circumstances.

Sec. 393.120 What are the rules for securing metal coils?

(a) Applicability. The rules in this section apply to the
transportation of one or more metal coils which, individually or grouped
together, weigh 2268 kg (5000 pounds) or more. Shipments of metal coils
that weigh less than 2268 kg (5000 pounds) may be secured in accordance
with the provisions of Secs. 393.100 through 393.114.

(b) Securement of coils transported with eyes vertical on a flatbed
vehicle, in a sided vehicle or intermodal container with anchor points--
(1) An individual coil. Each coil must be secured by tiedowns arranged
in a manner to prevent the coils from tipping in the forward, rearward,
and lateral directions. The restraint system must include the following:

(i) At least one tiedown attached diagonally from the left side of
the vehicle or intermodal container (near the forwardmost part of the
coil), across the eye of the coil, to the right side of the vehicle or
intermodal container (near the rearmost part of the coil);

(ii) At least one tiedown attached diagonally from the right side of
the vehicle or intermodal container (near the forwardmost part of the
coil), across the eye of the coil, to the left side of the vehicle or
intermodal container (near the rearmost part of the coil);

(iii) At least one tiedown attached transversely over the eye of the
coil; and

(iv) Either blocking and bracing, friction mats or tiedowns must be
used to prevent longitudinal movement in the forward direction.

(2) Coils grouped in rows. When coils are grouped and loaded side by
side in a transverse or longitudinal row, the each row of coils must be
secured by the following:

(i) At least one tiedown attached to the front of the row of coils,
restraining against forward motion, and whenever practicable, making an
angle no more than 45 degrees with the floor of the vehicle or
intermodal container when viewed from the side of the vehicle or
container;

(ii) At least one tiedown attached to the rear of the row of coils,
restraining against rearward motion, and whenever practicable, making an
angle no more than 45 degrees with the floor of the vehicle or
intermodal container when viewed from the side of the vehicle or
container;

(iii) At least one tiedown over the top of each coil or transverse
row of coils, restraining against vertical motion. Tiedowns going over
the top of a coil(s) must be as close as practicable to the eye of the
coil and positioned to prevent the tiedown from slipping or becoming
unintentionally unfastened while the vehicle is in transit; and

(iv) Tiedowns must be arranged to prevent shifting or tipping in the
forward, rearward and lateral directions.

(c) Securement of coils transported with eyes crosswise on a flatbed
vehicle, in a sided vehicle or intermodal container with anchor points--
(1) An individual coil. Each coil must be secured by the following:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to
prevent the coil from rolling. The means of preventing rolling must
support the coil off the deck, and must not be capable of becoming
unintentionally unfastened or loose while the vehicle is in transit. If
timbers, chocks or wedges are used, they must be held in place by coil
bunks or similar devices to prevent them from coming loose. The use of
nailed blocking or cleats as the sole means to secure timbers, chocks or
wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown through its eye, restricting against
forward motion, and whenever practicable, making an angle no more than
45 degrees with the floor of the vehicle or intermodal container when
viewed from the side of the vehicle or container; and

(iii) At least one tiedown through its eye, restricting against
rearward motion, and whenever practicable, making an angle no more than
45 degrees with the floor of the vehicle or intermodal container when
viewed from the side of the vehicle or container.

(2) Prohibition on crossing of tiedowns when coils are transported
with eyes crosswise. Attaching tiedowns diagonally through the eye of a
coil to form an X-pattern when viewed from above the vehicle is
prohibited.

(d) Securement of coils transported with eyes lengthwise on a
flatbed vehicle, in a sided vehicle or intermodal container with anchor
points--(1) An individual coil-option 1. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to
prevent the coil from rolling. The means of preventing rolling must
support the coil off the deck, and must not be capable of becoming
unintentionally unfastened or loose while the vehicle is in transit. If
timbers, chocks or wedges are used, they must be held in place by coil
bunks or similar devices to prevent them from coming loose. The use of
nailed blocking or cleats as the sole means to secure timbers, chocks or
wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown attached diagonally through its eye from
the left side of the vehicle or intermodal container (near the forward-
most part of the coil), to the right side of the vehicle or intermodal
container (near the rearmost part of the coil), making an angle no more
than 45 degrees, whenever practicable, with the floor of the vehicle or
intermodal container when viewed from the side of the vehicle or
container;

(iii) At least one tiedown attached diagonally through its eye, from
the right side of the vehicle or intermodal container (near the forward-
most part of the coil), to the left side of the vehicle or intermodal
container (near the rearmost part of the coil), making an angle no more
than 45 degrees, whenever practicable, with the floor of the vehicle or
intermodal container when viewed from the side of the vehicle or
container;

(iv) At least one tiedown attached transversely over the top of the
coil; and

(v) Either blocking, or friction mats to prevent longitudinal
movement.

(2) An individual coil--option 2. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to
prevent the coil from rolling. The means of preventing rolling must
support the coil off the deck, and must not be capable of becoming
unintentionally unfastened or loose while the vehicle is in transit. If
timbers, chocks or wedges are used, they must be held in place by coil
bunks or similar devices to prevent them from coming loose. The use of
nailed blocking or cleats as the sole means to secure timbers, chocks or
wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown attached straight through its eye from the
left side of the vehicle or intermodal container (near the forward-most
part of the coil), to the left side of the vehicle or intermodal
container (near the rearmost part of the coil), and, whenever
practicable, making an angle no more than 45 degrees with the floor 
of the vehicle or intermodal container when viewed from the side of 
the vehicle or container;

(iii) At least one tiedown attached straight through its eye, from
the right side of the vehicle or intermodal container (near the forward-
most part of the coil), to the right side of the vehicle or intermodal
container (near the rearmost part of the coil), and whenever
practicable, making an angle no more than 45 degrees with the floor of
the vehicle or intermodal container when viewed from the side of the
vehicle or container;

(iv) At least one tiedown attached transversely over the top of the
coil; and

(v) Either blocking or friction mats to prevent longitudinal
movement.

(3) An individual coil--option 3. Each coil must be secured by:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to
prevent the coil from rolling. The means of preventing rolling must
support the coil off the deck, and must not be capable of becoming
unintentionally unfastened or loose while the vehicle is in transit. If
timbers, chocks or wedges are used, they must be held in place by coil
bunks or similar devices to prevent them from coming loose. The use of
nailed blocking or cleats as the sole means to secure timbers, chocks or
wedges, or a nailed wood cradle, is prohibited;

(ii) At least one tiedown over the top of the coil, located near the
forward-most part of the coil;

(iii) At least one tiedown over the top of the coil located near the
rearmost part of the coil; and

(iv) Either blocking or friction mats to prevent longitudinal
movement.he forward direction.

(4) Rows of coils. Each transverse row of coils having approximately
equal outside diameters must be secured with:

(i) A means (e.g., timbers, chocks or wedges, a cradle, etc.) to
prevent each coil in the row of coils from rolling. The means of
preventing rolling must support each coil off the deck, and must not be
capable of becoming unintentionally unfastened or loose while the
vehicle is in transit. If timbers, chocks or wedges are used, they must
be held in place by coil bunks or similar devices to prevent them from
coming loose. The use of nailed blocking or cleats as the sole means to
secure timbers, chocks or wedges, or a nailed wood cradle, is
prohibited;

(ii) At least one tiedown over the top of each coil or transverse
row, located near the forward-most part of the coil;

(iii) At least one tiedown over the top of each coil or transverse
row, located near the rearmost part of the coil; and

(iv) Either blocking, bracing or friction mats to prevent
longitudinal movement.

(e) Securement of coils transported in a sided vehicle without
anchor points or an intermodal container without anchor points. Metal
coils transported in a vehicle with sides without anchor points or an
intermodal container without anchor points must be loaded in a manner to
prevent shifting and tipping. The coils may also be secured using a
system of blocking and bracing, friction mats, tiedowns, or a
combination of these to prevent any horizontal movement and tipping.

Sec. 393.122 What are the rules for securing paper rolls?

(a) Applicability. The rules in this section apply to shipments of
paper rolls which, individually or together, weigh 2268 kg (5000 lb) or
more. Shipments of paper rolls that weigh less than 2268 kg (5000 lb),
and paper rolls that are unitized on a pallet, may either be secured in
accordance with the rules in this section or the requirements of
Secs. 393.100 through 393.114.

(b) Securement of paper rolls transported with eyes vertical in a
sided vehicle. (1) Paper rolls must be placed tightly against the walls
of the vehicle, other paper rolls, or other cargo, to prevent movement
during transit.

(2) If there are not enough paper rolls in the shipment to reach the
walls of the vehicle, lateral movement must be prevented by filling the
void, blocking, bracing, tiedowns or friction mats. The paper rolls may
also be banded together.

(3) When any void behind a group of paper rolls, including that at
the rear of the vehicle, exceeds the diameter of the paper rolls,
rearward movement must be prevented by friction mats, blocking, bracing, tiedowns, or
banding to other rolls.

(4)(i) If a paper roll is not prevented from tipping or falling
sideways or rearwards by vehicle structure or other cargo, and its width
is more than 2 times its diameter, it must be prevented from tipping or
falling by banding it to other rolls, bracing, or tiedowns.

(ii) If the forwardmost roll(s) in a group of paper rolls is not
prevented from tipping or falling forwards by vehicle structure or other
cargo and it is restrained against forward movement by friction mat(s)
alone, and its width is more than 1.75 times its diameter, it must be
prevented from tipping or falling forwards by banding it to other rolls,
bracing, or tiedowns.

(iii) Otherwise, when a paper roll or the forwardmost roll in groups
of rolls that are not prevented from tipping or falling forwards by
vehicle structure or other cargo and its width exceeds 1.25 times its
diameter it must be prevented from tipping or falling by banding it to
other rolls, bracing or tiedowns.

(5) If paper rolls are banded together, the rolls must be placed
tightly against each other to form a stable group. The bands must be
applied tightly, and must be secured so that they cannot fall off the
rolls or to the deck.

(6) A friction mat used to provide the principal securement for a
paper roll must protrude from beneath the roll in the direction in which
it is providing that securement.

(c) Securement of split loads of paper rolls transported with eyes
vertical in a sided vehicle. (1) If a paper roll in a split load is not
prevented from forward movement by vehicle structure or other cargo, it
must be prevented from forward movement by filling the open space, or by
blocking, bracing, tiedowns, friction mats, or some combination of
these.

(2) A friction mat used to provide the principal securement for a
paper roll must protrude from beneath the roll in the direction in which
it is providing that securement.

(d) Securement of stacked loads of paper rolls transported with eyes
vertical in a sided vehicle. (1) Paper rolls must not be loaded on a
layer of paper rolls beneath unless the lower layer extends to the front
of the vehicle.

(2) Paper rolls in the second and subsequent layers must be
prevented from forward, rearward or lateral movement by means as allowed
for the bottom layer, or by use of a blocking roll from a lower layer.

(3) The blocking roll must be at least 38 mm (1.5 in) taller than
other rolls, or must be raised at least 38 mm (1.5 in) using dunnage.

(4) A roll in the rearmost row of any layer must not be raised using
dunnage.

(e) Securement of paper rolls transported with eyes crosswise in a
sided vehicle. (1) The paper rolls must be prevented from rolling or
shifting longitudinally by contact with vehicle structure or other
cargo, by chocks, wedges or blocking and bracing of adequate size, or by
tiedowns.

(2) Chocks, wedges or blocking must be held securely in place by
some means in addition to friction, so they cannot become
unintentionally unfastened or loose while the vehicle is in transit.

(3) The rearmost roll must not be secured using the rear doors of
the vehicle or intermodal container, or by blocking held in place by
those doors.

(4) If there is more than a total of 203 mm (8 in) of space between
the ends of a paper roll, or a row of rolls, and the walls of the
vehicle, void fillers, blocking, bracing, friction mats, or tiedowns
must be used to prevent the roll from shifting towards either wall.

(f) Securement of stacked loads of paper rolls transported with eyes
crosswise in a sided vehicle. (1) Rolls must not be loaded in a second
layer unless the bottom layer extends to the front of the vehicle.

(2) Rolls must not be loaded in a third or higher layer unless all
wells in the layer beneath are filled.

(3) The foremost roll in each upper layer, or any roll with an empty
well in front of it, must be secured against forward movement by:

(i) Banding it to other rolls, or

(ii) Blocking against an adequately secured eye-vertical blocking
roll resting on the floor of the vehicle which is at least 1.5 times 
taller than the diameter of the roll being blocked, or

(iii) Placing it in a well formed by two rolls on the lower row
whose diameter is equal to or greater than that of the roll on the upper
row.

(4) The rearmost roll in each upper layer must be secured by banding
it to other rolls if it is located in either of the last two wells
formed by the rearmost rolls in the layer below.

(5) Rolls must be secured against lateral movement by the same means
allowed for the bottom layer when there is more than a total of 203 mm
(8 in) of space between the ends of a paper roll, or a row of rolls, and
the walls of the vehicle.

(g) Securement of paper rolls transported with the eyes lengthwise
in a sided vehicle.

(1) Each roll must be prevented from forward movement by contact
with vehicle structure, other cargo, blocking or tiedowns.

(2) Each roll must be prevented from rearward movement by contact
with other cargo, blocking, friction mats or tiedowns.

(3) The paper rolls must be prevented from rolling or shifting
laterally by contact with the wall of the vehicle or other cargo, or by
chocks, wedges or blocking of adequate size.

(4) Chocks, wedges or blocking must be held securely in place by
some means in addition to friction, so they cannot become
unintentionally unfastened or loose while the vehicle is in transit.

(h) Securement of stacked loads of paper rolls transported with the
eyes lengthwise in a sided vehicle. (1) Rolls must not be loaded in a
higher layer if another roll will fit in the layer beneath.

(2) An upper layer must be formed by placing paper rolls in the
wells formed by the rolls beneath.

(3) A roll in an upper layer must be secured against forward and
rearward movement by any of the means allowed for the bottom layer, by
use of a blocking roll, or by banding to other rolls.

(i) Securement of paper rolls transported on a flatbed vehicle or in
a curtain-sided vehicle--(1) Paper rolls with eyes vertical or with eyes
lengthwise.

(i) The paper rolls must be loaded and secured as described for a
sided vehicle, and the entire load must be secured by tiedowns in
accordance with the requirements of Secs. 393.100 through 393.114.

(ii) Stacked loads of paper rolls with eyes vertical are prohibited.

(2) Paper rolls with eyes crosswise.

(i) The paper rolls must be prevented from rolling or shifting longitudinally 
by contact with vehicle structure or other cargo, by chocks, wedges or 
blocking and bracing of adequate size, or by tiedowns.

(ii) Chocks, wedges or blocking must be held securely in place by
some means in addition to friction so that they cannot become
unintentionally unfastened or loose while the vehicle is in transit.

(iii) Tiedowns must be used in accordance with the requirements of
Secs. 393.100 through 393.114 to prevent lateral movement.

Sec. 393.124 What are the rules for securing concrete pipe?

(a) Applicability. (1) The rules in this section apply to the
transportation of concrete pipe on flatbed trailers and vehicles, and
lowboy trailers.

(2) Concrete pipe bundled tightly together into a single rigid
article that has no tendency to roll, and concrete pipe loaded in a
sided vehicle or container must be secured in accordance with the
provisions of Secs. Sec. 393.100 through 393.114.

(b) General specifications for tiedowns. (1) The aggregate working
load limit of all tiedowns on any group of pipes must not be less than
half the total weight of all the pipes in the group.

(2) A transverse tiedown through a pipe on an upper tier or over
longitudinal tiedowns is considered to secure all those pipes beneath on
which that tiedown causes pressure.

(c) Blocking. (1) Blocking may be one or more pieces placed
symmetrically about the center of a pipe.

(2) One piece must extend at least half the distance from the center
to each end of the pipe, and two pieces must be placed on the opposite
side, one at each end of the pipe.

(3) Blocking must be placed firmly against the pipe, and must be
secured to prevent it moving out from under the pipe.

(4) Timber blocking must have minimum dimensions of at least 10 x 15
cm (4 x 6 in).

(d) Arranging the load--(1) Pipe of different diameter. If pipe of
more than one diameter are loaded on a vehicle, groups must be formed
that consist of pipe of only one size, and each group must be separately
secured.

(2) Arranging a bottom tier. The bottom tier must be arranged to
cover the full length of the vehicle, or as a partial tier in one group
or two groups.

(3) Arranging an upper tier. Pipe must be placed only in the wells
formed by adjacent pipes in the tier beneath. A third or higher tier
must not be started unless all wells in the tier beneath are filled.

(4) Arranging the top tier. The top tier must be arranged as a
complete tier, a partial tier in one group, or a partial tier in two
groups.

(5) Arranging bell pipe. (i) Bell pipe must be loaded on at least
two longitudinal spacers of sufficient height to ensure that the bell is
clear of the deck.

(ii) Bell pipe loaded in one tier must have the bells alternating on
opposite sides of the vehicle.

(iii) The ends of consecutive pipe must be staggered, if possible,
within the allowable width, otherwise they must be aligned.

(iv) Bell pipe loaded in more than one tier must have the bells of
the bottom tier all on the same side of the vehicle.

(v) Pipe in every upper tier must be loaded with bells on the
opposite side of the vehicle to the bells of the tier below.

(vi) If the second tier is not complete, pipe in the bottom tier
which do not support a pipe above must have their bells alternating on
opposite sides of the vehicle.

(e) Securing pipe with an inside diameter up to 1,143 mm (45 in). In
addition to the requirements of paragraphs (b), (c) and (d) of this
section, the following rules must be satisfied:

(1) Stabilizing the bottom tier. (i) The bottom tier must be
immobilized longitudinally at each end by blocking, vehicle end
structure, stakes, a locked pipe unloader, or other equivalent means.

(ii) Other pipe in the bottom tier may also be held in place by
blocks and/or wedges; and

(iii) Every pipe in the bottom tier must also be held firmly in
contact with the adjacent pipe by tiedowns though the front and rear
pipes:

(A) At least one tiedown through the front pipe of the bottom tier
must run aft at an angle not more than 45 degrees with the horizontal,
whenever practicable.

(B) At least one tiedown through the rear pipe of the bottom tier
must run forward at an angle not more than 45 degrees with the
horizontal, whenever practicable.

(2) Use of tiedowns. (i) Each pipe may be secured individually with
tiedowns through the pipe.

(ii) If each pipe is not secured individually with a tiedown, then:

(A) Either one 1/2-inch diameter chain or wire rope, or two 3/8-inch
diameter chain or wire rope, must be placed longitudinally over the
group of pipes;

(B) One transverse tiedown must be used for every 3.04 m (10 ft) of
load length. The transverse tiedowns may be placed through a pipe, or
over both longitudinal tiedowns between two pipes on the top tier.

(C) If the first pipe of a group in the top tier is not placed in
the first well formed by pipes at the front of the tier beneath, it must
be secured by an additional tiedown that runs rearward at an angle not
more than 45 degrees to the horizontal, whenever practicable. This
tiedown must pass either through the front pipe of the upper tier, or
outside it and over both longitudinal tiedowns; and

(D) If the last pipe of a group in the top tier is not placed in the
last well formed by pipes at the rear of the tier beneath, it must be
secured by an additional tiedown that runs forward at an angle not more
than 45 degrees to the horizontal, whenever practicable. This tiedown
must pass either through the rear pipe of the upper tier or outside it
and over both longitudinal tiedowns.

(f) Securing large pipe, with an inside diameter over 1143 mm (45
in). In addition to the requirements of paragraphs (b), (c) and (d) of
this section, the following rules must be satisfied:

(1) The front pipe and the rear pipe must be immobilized by
blocking, wedges, vehicle end structure, stakes, locked pipe unloader,
or other equivalent means.

(2) Each pipe must be secured by tiedowns through the pipe:

(i) At least one tiedown through each pipe in the front half of the
load, which includes the middle one if there is an odd number, and must
run rearward at an angle not more than 45 degrees with the horizontal,
whenever practicable.

(ii) At least one tiedown through each pipe in the rear half of the
load, and must run forward at an angle not more than 45 degrees with the
horizontal, whenever practicable, to hold each pipe firmly in contact
with adjacent pipe; and

(iii) If the front or rear pipe is not also in contact with vehicle
end structure, stakes, a locked pipe unloader, or other equivalent
means, at least two tiedowns positioned as described in paragraphs
(f)(2)(i) and (ii) of this section, must be used through that pipe.

(3) If only one pipe is transported, or if several pipes are
transported without contact between other pipes, the requirements in
this paragraph apply to each pipe as a single front and rear article.

Sec. 393.126 What are the rules for securing intermodal containers?

(a) Applicability. The rules in this section apply to the
transportation of intermodal containers. Cargo contained within an
intermodal container must be secured in accordance with the provisions
of Secs. 393.100 through 393.114 or, if applicable, the commodity
specific rules of this part.

(b) Securement of intermodal containers transported on container
chassis vehicle(s). (1) Each intermodal container must be secured to the
container chassis with securement devices or integral locking devices
that cannot unintentionally become unfastened while the vehicle is in
transit.

(2) The securement devices must restrain the container from moving
more than 1.27 cm (1/2 in) forward, more than 1.27 cm (1/2 in) aft, more
than 1.27 cm (1/2 in) to the right, more than 1.27 cm (1/2 in) to the
left, or more than 2.54 cm (1 in) vertically.

(3) The front and rear of the container must be secured
independently.

(c) Securement of loaded intermodal containers transported on
vehicles other than container chassis vehicle(s). (1) All lower corners
of the intermodal container must rest upon the vehicle, or the corners
must be supported by a structure capable of bearing the weight of the
container and that support structure must be independently secured to
the motor vehicle.

(2) Each container must be secured to the vehicle by:
(i) Chains, wire ropes or integral devices which are fixed to all
lower corners; or

(ii) Crossed chains which are fixed to all upper corners; and,

(3) The front and rear of the container must be secured
independently. Each chain, wire rope, or integral locking device must be
attached to the container in a manner that prevents it from being
unintentionally unfastened while the vehicle is in transit.

(d) Securement of empty intermodal containers transported on
vehicles other than container chassis vehicle(s). Empty intermodal
containers transported on vehicles other than container chassis vehicles
do not have to have all lower corners of the intermodal container
resting upon the vehicle, or have all lower corners supported by a
structure capable of bearing the weight of the empty container,
provided:

(1) The empty intermodal container is balanced and positioned on the
vehicle in a manner such that the container is stable before the
addition of tiedowns or other securement equipment; and,

(2) The amount of overhang for the empty container on the trailer
does not exceed five feet on either the front or rear of the trailer;

(3) The empty intermodal container must not interfere with the
vehicle's maneuverability; and,

(4) The empty intermodal container is secured to prevent lateral,
longitudinal, or vertical shifting.

Sec. 393.128 What are the rules for securing automobiles, light trucks and vans?

(a) Applicability. The rules in this section apply to the transportation 
of automobiles, light trucks, and vans which individually weigh 4,536 kg.
(10,000 lb) or less. Vehicles which individually are heavier than 4,536
kg (10,000 lb) must be secured in accordance with the provisions of
Sec. 393.130 of this part.

(b) Securement of automobiles, light trucks, and vans.

(1) Automobiles, light trucks, and vans must be restrained at both
the front and rear to prevent lateral, forward, rearward, and vertical
movement using a minimum of two tiedowns.

(2) Tiedowns that are designed to be affixed to the structure of the
automobile, light truck, or van must use the mounting points on those
vehicles that have been specifically designed for that purpose.

(3) Tiedowns that are designed to fit over or around the wheels of
an automobile, light truck, or van must provide restraint in the
lateral, longitudinal and vertical directions.

(4) Edge protectors are not required for synthetic webbing at points
where the webbing comes in contact with the tires.

Sec. 393.130 What are the rules for securing heavy vehicles, equipment and machinery?

(a) Applicability. The rules in this section apply to the
transportation of heavy vehicles, equipment and machinery which operate
on wheels or tracks, such as front end loaders, bulldozers, tractors,
and power shovels and which individually weigh 4,536 kg (10,000 lb.) or
more. Vehicles, equipment and machinery which is lighter than 4,536 kg
(10,000 lb.) may also be secured in accordance with the provisions of
this section, with Sec. 393.128, or in accordance with the provisions of
Secs. 393.100 through 393.114.

(b) Preparation of equipment being transported. (1) Accessory
equipment, such as hydraulic shovels, must be completely lowered and
secured to the vehicle.

(2) Articulated vehicles shall be restrained in a manner that
prevents articulation while in transit.

(c) Securement of heavy vehicles, equipment or machinery with
crawler tracks or wheels. (1) In addition to the requirements of
paragraph (b) of this section, heavy equipment or machinery with crawler
tracks or wheels must be restrained against movement in the lateral,
forward, rearward, and vertical direction using a minimum of four
tiedowns.

(2) Each of the tiedowns must be affixed as close as practicable to
the front and rear of the vehicle, or mounting points on the vehicle
that have been specifically designed for that purpose.

Sec. 393.132 What are the rules for securing flattened or crushed vehicles?

(a) Applicability. The rules in this section apply to the
transportation of vehicles such as automobiles, light trucks, and vans
that have been flattened or crushed.

(b) Prohibition on the use of synthetic webbing. The use of
synthetic webbing to secure flattened or crushed vehicles is prohibited.

(c) Securement of flattened or crushed vehicles. Flattened or
crushed vehicles must be transported on vehicles which have:

(1) Containment walls or comparable means on four sides which extend
to the full height of the load and which block against movement of the
cargo in the forward, rearward and lateral directions; or

(2)(i) Containment walls or comparable means on three sides which
extend to the full height of the load and which block against movement
of the cargo in the forward, rearward and the lateral direction for
which there is no containment wall or comparable means, and

(ii) A minimum of two tiedowns are required per vehicle stack; or

(3)(i) Containment walls on two sides which extend to the full
height of the load and which block against movement of the cargo in the
forward and rearward directions, and

(ii) A minimum of three tiedowns are required per vehicle stack; or

(4) A minimum of four tiedowns per vehicle stack.

(5) In addition to the requirements of paragraphs (c)(2), (3), and

(4), the following rules must be satisfied:

(i) Vehicles used to transport flattened or crushed vehicles must be
equipped with a means to prevent loose parts from falling from all four 
sides of the vehicle which extends to the full height of the cargo.

(ii) The means used to contain loose parts may consist of structural
walls, sides or sideboards, or suitable covering material, alone or in
combinations.

(iii) The use of synthetic material for containment of loose parts
is permitted.

Sec. 393.134 What are the rules for securing roll-on/roll-off or hook lift containers?

(a) Applicability. The rules in this section apply to the
transportation of roll-on/roll-off or hook lift containers.

(b) Securement of a roll-on/roll-off and hook lift container. Each
roll-on/roll-off and hook lift container carried on a vehicle which is
not equipped with an integral securement system must be:

(1) Blocked against forward movement by the lifting device, stops, a
combination of both or other suitable restraint mechanism;

(2) Secured to the front of the vehicle by the lifting device or
other suitable restraint against lateral and vertical movement;

(3) Secured to the rear of the vehicle with at least one of the
following mechanisms:

(i) One tiedown attached to both the vehicle chassis and the
container chassis;

(ii) Two tiedowns installed lengthwise, each securing one side of
the container to one of the vehicle's side rails; or

(iii) Two hooks, or an equivalent mechanism, securing both sides of
the container to the vehicle chassis at least as effectively as the
tiedowns in the two previous items.

(4) The mechanisms used to secure the rear end of a roll-on/roll off
or hook lift container must be installed no more than two meters (6 ft 7
in) from the rear of the container.

(5) In the event that one or more of the front stops or lifting
devices are missing, damaged or not compatible, additional manually
installed tiedowns must be used to secure the container to the vehicle,
providing the same level of securement as the missing, damaged or
incompatible components.

Sec. 393.136 What are the rules for securing large boulders?

(a) Applicability. (1) The rules in this section are applicable to
the transportation of any large piece of natural, irregularly shaped
rock weighing in excess of 5,000 kg (11,000 lb.) or with a volume in
excess of 2 cubic-meters on an open vehicle, or in a vehicle whose sides
are not designed and rated to contain such cargo.

(2) Pieces of rock weighing more than 100 kg (220 lb.), but less
than 5,000 kg (11,000 lb.) must be secured, either in accordance with
this section, or in accordance with the provisions of Secs. 393.100
through 393.114, including:

(i) Rock contained within a vehicle which is designed to carry such
cargo; or

(ii) Secured individually by tiedowns, provided each piece can be
stabilized and adequately secured.

(3) Rock which has been formed or cut to a shape and which provides
a stable base for securement must also be secured, either in accordance
with the provisions of this section, or in accordance with the
provisions of Secs. 393.100 through 393.114.

(b) General requirements for the positioning of boulders on the
vehicle. (1) Each boulder must be placed with its flattest and/or
largest side down.

(2) Each boulder must be supported on at least two pieces of hard
wood blocking at least 10 cm x 10 cm (4 inches x 4 inches) side
dimensions extending the full width of the boulder.

(3) Hardwood blocking pieces must be placed as symmetrically as
possible under the boulder and should support at least three-fourths of
the length of the boulder.

(4) If the flattest side of a boulder is rounded or partially
rounded, so that the boulder may roll, it must be placed in a crib made
of hardwood timber fixed to the deck of the vehicle so that the boulder
rests on both the deck and the timber, with at least three well-
separated points of contact that prevent its tendency to roll in any
direction.

(5) If a boulder is tapered, the narrowest end must point towards
the front of the vehicle.

(c) General tiedown requirements. (1) Only chain may be used as
tiedowns to secure large boulders.

(2) Tiedowns which are in direct contact with the boulder should,
where possible, be located in valleys or notches across the top of the
boulder, and must be arranged to prevent sliding across the rock
surface.

(d) Securement of a cubic shaped boulder. In addition to the
requirements of paragraphs (b) and (c) of this section, the following
rules must be satisfied:

(1) Each boulder must be secured individually with at least two
chain tiedowns placed transversely across the vehicle.

(2) The aggregate working load limit of the tiedowns must be at
least half the weight of the boulder.

(3) The tiedowns must be placed as closely as possible to the wood
blocking used to support the boulder.

(e) Securement of a non-cubic shaped boulder--with a stable base. In
addition to the requirements of paragraphs (b) and (c) of this section,
the following rules must be satisfied:

(1) The boulder must be secured individually with at least two chain
tiedowns forming an ``X'' pattern over the boulder.

(2) The aggregate working load limit of the tiedowns must be at
least half the weight of the boulder.

(3) The tiedowns must pass over the center of the boulder and must
be attached to each other at the intersection by a shackle or other
connecting device.

(f) Securement of a non-cubic shaped boulder--with an unstable base.
In addition to the requirements of paragraphs (b) and (c) of this
section, each boulder must be secured by a combination of chain tiedowns
as follows:

(1) One chain must surround the top of the boulder (at a point
between one-half and two-thirds of its height). The working load limit
of the chain must be at least half the weight of the boulder.

(2) Four chains must be attached to the surrounding chain and the
vehicle to form a blocking mechanism which prevents any horizontal
movement. Each chain must have a working load limit of at least one-
fourth the weight of the boulder. Whenever practicable, the angle of the
chains must not exceed 45 degrees from the horizontal.

Sec. 393.201 Frames.

Source: 53 FR 49402, Dec. 7, 1988, unless otherwise noted.

(a) The frame of every bus, truck, and truck tractor shall not be
cracked, loose, sagging or broken.

(b) Bolts or brackets securing the cab or the body of the vehicle to
the frame must not be loose, broken, or missing.

(c) The frame rail flanges between the axles shall not be bent, cut
or notched, except as specified by the manufacturer.

(d) All accessories mounted to the truck tractor frame must be
bolted or riveted.

(e) No holes shall be drilled in the top or bottom rail flanges,
except as specified by the manufacturer.

(f) Field repairs are allowed.

Sec. 393.203 Cab and body components.

(a) The cab compartment doors or door parts used as an entrance or
exist shall not be missing or broken. Doors shall not sag so that they
cannot be properly opened or closed. No door shall be wired shut or
otherwise secured in the closed position so that it cannot be readily
opened. Exception: When the vehicle is loaded with pipe or bar stock
that blocks the door and the cab has a roof exit.

(b) Bolts or brackets securing the cab or the body of the vehicle to
the frame shall not be loose, broken, or missing.

(c) The hood must be securely fastened.

(d) All seats must be securely mounted.

(e) The front bumper must not be missing, loosely attached, or
protruding beyond the confines of the vehicle so as to create a hazard.

Sec. 393.205 Wheels.

(a) Wheels and rims shall not be cracked or broken.

(b) Stud or bolt holes on the wheels shall shall not be elongated
(out of round).

(c) Nuts or bolts shall not be missing or loose.

Sec. 393.207 Suspension systems.

(a) Axles. No axle positioning part shall be cracked, broken, loose
or missing. All axles must be in proper alignment.

(b) Adjustable axles. Adjustable axle assemblies shall not have
locking pins missing or disengaged.

(c) Leaf springs. No leaf spring shall be cracked, broken, or
missing nor shifted out of position.

(d) Coil springs. No coil spring shall be cracked or broken.

(e) Torsion bar. No torsion bar or torsion bar suspension shall be
cracked or broken.

(f) Air suspensions. The air pressure regulator valve shall not
allow air into the suspension system until at least 55 psi is in the
braking system. The vehicle shall be level (not tilting to the left or
right). Air leakage shall not be greater than 3 psi in a 5-minute time
period when the vehicle's air pressure gauge shows normal operating
pressure.

Sec. 393.209 Steering wheel systems.

(a) The steering wheel shall be secured and must not have any spokes
cracked through or missing.

(b) The steering wheel lash shall not exceed the following
parameters:

(c) Steering column. The steering column must be securely fastened.

(d) Steering system. Universal joints shall not be worn, faulty or
repaired by welding. The steering gear box shall not have loose or
missing mounting bolts or cracks in the gear box or mounting brackets.
The pitman arm on the steering gear output shaft shall not be loose.
Steering wheels shall turn freely through the limit of travel in both
directions.

(e) Power steering systems. All components of the power system must
be in operating condition. No parts shall be loose or broken. Belts
shall not be frayed, cracked or slipping. The system shall not leak. The
power steering system shall have sufficient fluid in the reservoir.

PART 394 [RESERVED]

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