Interpretation ID: nht74-2.8

DATE: 11/06/74

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Truck Body and Equipment Association, Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your October 3, 1974, questions whether the exemption for 24,000-pound axle vehicles from Standard No. 121, Air brake systems, until September 1, 1976, applies to fire fighting vehicles, and whether a tandem axle assembly consits of two "axle systems" for purposes of our definition of "Gross axle weight rating."

The answer to both of your questions is yes. A fire fighting vehicle would qualify for exemption until 1976 if any of its axles has a gross axle weight rating of 24,000 pounds or more.

A tandem axle assembly, which we understand to mean a running rear assembly consisting of two axles and associated components, comprises two "axle systems." As we pointed out in the preamble to Notice 2 of Docket No. 74-10, the term "axle system" is used only to avoid confusion in situations where a suspension system does not employ an axle (39 FR 17550, May 17, 1974).

Yours truly,

ATTACH.

TRUCK BODY AND EQUIPMENT ASSOCIATION, (Illegible Word)

October 3, 1974

Richard Dyson -- Office of Chief Council, National Highway Traffic Safety Administration

Dear Mr. Dyson:

Recently several members of our Fire Apparatus Manufacturers Division have contacted us with questions concerning FMVSS 121 and its effective date. In order that we may accurately answer these questions, we would like the following clarified.

(1) Does a fire apparatus qualify for the "Special Permit Vehicle" classification if it is equipped with an axle with a GAWR equal to or greater than twenty-four thousand pounds (24,000 lbs.)?

(2) Is a tandem axle assembly comprised of two "Axle Systems", per your GAWR definition?

Your cooperation in this matter is greatly appreciated.

Sincerely yours,

Byron Crampton -- Manager of Engineering Services