Interpretation ID: nht75-5.46

DATE: 09/08/75

FROM: AUTHOR UNAVAILABLE; James B. Gregory; NHTSA

TO: Jack Johnson

TITLE: FMVSS INTERPRETATION

TEXT: This responds to Motac's August 7, 1975, request for a determination that two platform trailers which are designed with a primary cargo-carrying surface which is less than 40 inches above the ground would qualify for exclusion from the requirements of Standard No. 121, Air Brake Systems, if manufactured before September 1, 1976.

I have enclosed a copy of the amendment to Standard No. 121 which excludes heavy hauler trailers from the requirements of the standard until September 1, 1976. You should note that the "40-inch cargo-carrying surface" criterion is measured in the unloaded condition, and that the body must not be equipped with sidewalls unless they are easily removable.

There is no requirement that the vehicle be designed for a certain type of cargo such as heavy machinery. Therefore your semi-trailers may qualify for the exclusion if they meet the criteria listed in the definition of heavy hauler trailer.

SINCERELY,

August 7, 1975

Department of Transportation

Attention: James B. Gregory Administrator

Regarding: FMVSS 121 Air Brake System- Trucks, Buses & Trailers. Clarification of docket no. 74-10; notice 5 and docket no's. 70-16, 70-17; notice no. 2.

We would appreciate your clarification of the above referenced documents regarding "Heavy Hauler Trailer", item 2, which states that "whose primary cargo-carrying surface is not more than 40 inches above the ground in an unloaded condition, etc.", is exempt from the antilock brake until Sept. 1, 1976.

We manufacture commercial platform trailers of various types at our West Coast factory. One type of trailer is a drop frame low platform semi-trailer, both single and tandem axle in lengths from 26 ft. long to 45 ft. long. They are equipped with 8:25 x 15 tires, therefore the "primary cargo-carrying surface", aft of the gooseneck drop, is 36 inches for the single axle semi-trailers and 39" for the tandem axle trailers from the ground.

These trailers are used for transporting furniture containers (4' long, x 8' wide x 8' plus or minus high), full grown nursury trees in large root containing boxes, or many types of general freight that is compatible to a drop frame low platform semi-trailer.

Since these trailers comply with the deck height of 40 inches or less for their primary "cargo-carrying surface", please advise if they are exempt from the antilock brake equipment. These trailers are not designed to transport such items as "crawler tractors, boom cranes, heavy machinery, etc."

MOTAC, INC.

Jack Johnson

Chief Engineer