Interpretation ID: aiam2886
Rome Engineering & Manufacturing Co.
P.O. Box 707
Claxton
GA 30417;
Dear Mr. Nettles: This responds to REMCO's September 14, 1978, request to know th Federal braking requirements for an air-braked or pulpwood trailer.; In addition to the requirements of Standard No. 106-74, *Brake Hoses* the only Federal Motor Vehicle Safety Standard regulating the braking of air-braked vehicles is Standard No. 121, *Air Brake Systems*. As you know, Federal Motor Carrier Safety Standards also apply to the use of air-braked vehicles in interstate commerce.; All of the requirements of Standard No. 121 apply to the manufacture o a logging or pulpwood trailer except for the 'no lockup' provision of S5.3.2. Specifically, S5.3.2.2 of the standard states:; >>>S5.3.2.2 When stopped in accordance with S5.3.2, any traile designed exclusively for harvesting logs or pulpwood and constructed with a skeletal frame and no means for attachment of a solid bed, body, or container, and with an arrangement of air control lines and reservoirs designed to minimize damage in off- road operations, need not meet the requirements relating to wheel lockup, but must nevertheless meet the requirements of staying within the 12-foot lane.<<<; There is no exclusion from the parking brake requirements of S5.6 Therefore, a parking brake capability using an energy source unaffected by loss of service brake air pressure is required. The standard specifies performance, not design, and does not require installation of a spring brake design. I have enclosed a copy of a recent proposal that would modify the requirements so that pulpwood trailers would not be required to provide parking brake capability. The reasons for this proposal are listed in the preamble to the notice. This proposal has not been made final.; For clarification, I would add that 'heavy hauler' trailers ar excluded from the entire standard until January 1, 1979. Heavy hauler trailers are defined to include the so-called 'pole trailers' used in logging that have air brake lines that adapt to fore-and-aft extension of the trailer.; I am also enclosing a *Federal Register* notice that explains th effect of a recent court decision on the 'no lockup' requirement for trailers.; Sincerely, Joseph J. Levin, Jr., Chief Counsel