For TruckTalk visitor's convenience here is a copy of standard 224 directly
from the GPO site.
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WAIS Document Retrieval[Code of Federal Regulations]
[Title 49, Volume 5, Parts 400 to 999]
[Revised as of October 1, 1998]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.224]
[Page 677-679]
TITLE 49--TRANSPORTATION
CHAPTER V--NATIONAL HIGHWAY TRAFFIC
SAFETY ADMINISTRATION, DEPARTMENT
OF TRANSPORTATION
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents
Subpart B--Federal Motor Vehicle Safety Standards
Sec. 571.224 Standard No. 224; Rear impact protection.
S1. Scope. This standard establishes requirements for the
installation of rear impact guards on trailers and semitrailers with a
gross vehicle weight rating (GVWR) of 4,536 kg or more.
S2. Purpose. The purpose of this standard is to reduce the number of
deaths and serious injuries occurring when light duty vehicles impact
the rear of trailers and semitrailers with a GVWR of 4,536 kg or more.
S3. Application. This standard applies to trailers and semitrailers
with a GVWR of 4,536 kg or more. The standard does not apply to pole
trailers, pulpwood trailers, special purpose vehicles, wheels back
vehicles, or temporary living quarters as defined in 49 CFR 529.2. If a
cargo tank motor vehicle, as defined in 49 CFR 171.8, is certified to
carry hazardous materials and has a rear bumper or rear end protection
device conforming with 49 CFR part 178 located in the area of the
horizontal member of the rear underride guard required by this standard,
the guard need not comply with the energy absorption requirement
(S5.2.2) of 49 CFR 571.223.
S4. Definitions.
Chassis means the load supporting frame structure of a motor
vehicle.
Horizontal member means the structural member of the guard that
meets the configuration requirements of S5.1 of this section when the
guard is installed on the vehicle according to the installation
instructions or procedures required by S5.5 of Sec. 571.223, Rear Impact
Guards.
Low chassis vehicle means a trailer or semitrailer having a chassis
that extends behind the rearmost point of the rearmost tires and a lower
rear surface that meets the configuration requirements of S5.1.1 through
5.1.3 of this section.
Outer or Outboard means away from the trailer centerline and toward
the side extremities of the trailer.
Pulpwood trailer means a trailer 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.
Rear extremity means the rearmost point on a vehicle that is above a
horizontal plane located 560 mm above the ground and below a horizontal
plane located 1,900 mm above the ground when the vehicle is configured
as specified in S5.1 of this section and when the 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
taillights, rubber bumpers, hinges and latches are excluded from the
determination of the rearmost point.
Rounded corner means a guard's outermost end that curves upward or
forward toward the front of the vehicle, or both.
Side extremity means the outermost point on a vehicle's side that is
located above a horizontal plane 560 mm above the ground, below a
horizontal plane located 190 cm 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 forward of that plane
when the vehicle is configured as specified in S5.1 of this section.
Non-structural protrusions such as taillights, hinges, rubber bumpers,
and latches are excluded from the determination of the outermost point.
Special purpose vehicle means a trailer or semitrailer having work-
performing equipment that, while the vehicle is in transit, resides in
or moves through the area that could be occupied by the horizontal
member of the rear underride guard, as defined by S5.1.1 through S5.1.3.
Wheels back vehicle means a trailer or semitrailer whose rearmost
axle is permanently fixed and is located such that the rearmost surface
of tires of the size recommended by the vehicle manufacturer for the
vehicle on that axle is not more than 305 mm forward of the transverse
vertical plane tangent to the rear extremity of the vehicle.
S5. Requirements.
S5.1 Installation; vehicle configuration. Each vehicle shall be
equipped with a rear impact guard certified as meeting Federal Motor
Vehicle Safety Standard
[[Page 678]]
No. 223, Rear Impact Guards (Sec. 571.223). When the vehicle to which
the guard is attached is resting on level ground, unloaded, with its
full capacity of fuel, and with its tires inflated and air suspension,
if so equipped, pressurized in accordance with the manufacturer's
recommendations, the guard shall comply with the requirements of S5.1.1
through S5.1.3 of this section. See Figure 1 of this section.
S5.1.1 Guard width. The outermost surfaces of the horizontal member
of the guard shall extend outboard to within 100 mm of the longitudinal
vertical planes that are tangent to the side extremities of the vehicle,
but shall not extend outboard of those planes. See Figure 1 of this
section.
S5.1.2 Guard height. The vertical distance between the bottom edge
of the horizontal member of the guard and the ground shall not exceed
560 mm at any point across the full width of the member. Notwithstanding
this requirement, guards with rounded corners may curve upward within
255 mm of the longitudinal vertical planes that are tangent to the side
extremities of the vehicle. See Figure 1 of this section.
S5.1.3 Guard rear surface. At any height 560 mm or more above the
ground, the rearmost surface of the horizontal member of the guard shall
be located as close as practical to a transverse vertical plane tangent
to the rear extremity of the vehicle, but no more than 305 mm forward of
that plane. Notwithstanding this requirement, the horizontal member may
extend rearward of the plane, and guards with rounded corners may curve
forward within 255 mm of the longitudinal vertical planes that are
tangent to the side extremities of the vehicle.
S5.2 Installation Requirements. Guards shall be attached to the
vehicle's chassis by the vehicle manufacturer in accordance with the
installation instructions or procedures provided pursuant to S5.5 of
Standard No. 223, Rear Impact Guards (Sec. 571.223). The vehicle must be
of a type identified in the installation instructions as appropriate for
the guard.
[[Page 679]]
[GRAPHIC] [TIFF OMITTED] TC01AU91.147
[61 FR 2035, Jan. 24, 1996, as amended at 63 FR 3662, Jan. 26, 1998]
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