Interpretation ID: aiam1902
Olson Trailer & Body Builders Co.
2740 S. Ashland
P.O. Box 2445
Green Bay
WI 54306;
Dear Mr. Moede: This responds to your April 7, 1975, questions whether the Olso two-axle, three-axle, and four-axle 'land-hog' trailers would qualify for exclusion from Standard No. 121, *Air brake systems*, until September 1, 1976, as 'heavy hauler' trailers or if equipped with an axle with a gross weight rating (GAWR) of 24,000 pounds or more.; The trailers you describe do not appear to qualify as a heavy haule trailer because they do not appear to have brake lines which adapt to separation or extension of the vehicle frame, or a bed height of 40 inches or less in the unloaded condition.; Standard No. 121 applies to most air-brake vehicles. Section S3 of th standard does exclude any vehicle manufactured before September 1, 1976, that has a gross axle weight rating for any axle of 24,000 pounds or more.; Yours truly, Richard B. Dyson, Assistant Chief Counsel