Interpretation ID: aiam1903
Mobilefreeze Co.
Inc.
P.O. Box 691
Parsons
KS 67357;
Dear Mr. Latzer: This responds to your April 15, 1975, question whether the Mobilefreez 'Mark Twain Marine' boat trailer, which consists of a platform whose primary cargo- carrying surface is 18 inches above the ground and supported by two 29-inch-high longitudinal support beams which rise from the outer edges of this surface, would qualify as a heavy hauler trailer. 'Heavy hauler trailer' is defined in S4 of Standard No 121, *Air brake systems*, as follows:; >>>'Heavy hauler trailer' means a trailer with one or more of th 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 S 393.106 of this title.<<<; From your description, the 29-inch-high beams do not serve as side from the trailer but simply as longitudinal load-bearing members of the vehicle's cargo-carrying surface. You state that these beams would be placed under the platform except for the necessity that the trailer bed be lower than normal.; If the beams in question do not in fact serve as sides but rather a part of the vehicle frame, the National Highway Traffic Safety Administration concludes that the 'Mark Twain Marine' boat trailer qualifies as a heavy hauler trailer which is not required to conform to Standard No. 121 until September 1, 1976.; Yours truly, Richard B. Dyson, Assistant Chief Counsel