Interpretation ID: aiam2297
Vice President & General Manager
Rome Engineering & Manufacturing Co.
P.O. Box 707
Claxton
GA 30417;
Dear Mr. Plummer: This responds to Remco's April 26, 1976, question whether an exclusio from a safety standard based on the gross axle weight rating (GAWR) of an axle is met by using the rating of the axle beam by its manufacturer, or whether the truck or trailer manufacturer must also consider the load-bearing abilities of the wheels, rims, and hubs used with the axle beam.; Gross axle weight rating is defined in 49 CFR 571.3 to mean: >>>. . .the value specified by the vehicle manufacturer as th load-carrying capacity of a single axle system, as measured at the tire-ground interfaces.<<<; This definition means that the determination of GAWR is made by th vehicle manufacturer and that the axle beam rating of the component suppler cannot be the only basis for GAWR calculation. The GAWR is the value established at the tire-ground interfaces at each wheel position, and this means that the wheels, rims, hubs, and tires must be included in the determination. Thus, with regard to the exclusion from Standard No. 121, *Air Brake Systems*, until September 1, 1977, for any vehicle with an axle that has a GAWR of 24,000 pounds or more, the vehicle manufacturer must take into consideration each component on the axle as well as its attachment to the vehicle frame.; Sincerely, Frank Berndt, Acting Chief Counsel