Interpretation ID: nht78-2.41

DATE: 03/22/78

FROM: AUTHOR UNAVAILABLE; J. J. Levin, Jr.; NHTSA

TO: Industrial Airport

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your February 16, 1978, request for confirmation that Standard No. 121, Air Brake Systems, does not apply to an air-braked trailer that carries no cargo and consists entirely of a mobile auto-crushing device.

Section S3 of Standard No. 121 contains an exclusion for any trailer whose unloaded vehicle weight is not less than 95 percent of its gross vehicle weight rating (GVWR). "Unloaded vehicle weight" means the weight of a vehicle with maximum capacity of all fluids necessary for operation of the vehicle, but without cargo or occupants. Thus, if your mobile auto-crushing trailer carries no cargo or cargo that is less than 5 percent of the vehicles GVWR, it would be excluded from the requirements of Standard No. 121.

I would note that Standard No. 108, Lamps, Relective Devices and Associated Equipment, and Standard No. 120, Tire Selection and Rims for Motor Vehicles other than Passenger Cars, may apply to the trailer you describe. I enclose an information sheet that describes where copies of these standards can be obtained.