Interpretation ID: nht92-3.28

DATE: 10/05/92

FROM: ROBERT F. GAYER -- EQUIPMENT COORDINATOR, TRANSPORTATION SERVICES, SALT RIVER PROJECT

TO: CHIEF COUNSEL -- NHTSA

COPYEE: TOM LANGENFELD -- GREAT DANE TRAILER

ATTACHMT: ATTACHED TO LETTER DATED 12-14-92 FROM PAUL J. RICE TO ROBERT F. GAYER (A40; STD. 121)

TEXT: Salt River Project, Transportation Services requests an interpretation of FMVSS 121 in regard to compliance of the brake systems on four (4) semi-trailers owned and operated on public streets and highways by Salt River Project. The manufacturer of the four trailers, Great Dane Trailer of Savannah Georgia has stated to Salt River Project that these trailers do not need to comply with "121", because they are "Heavy Haul Trailers". Salt River Project does not agree with Great Dane Trailer, and thus the request for the interpretation. All four (4) trailers are as follows:

Semi Trailer, flatbed, extendable - 40 feet to 65 feet.

GVWR - 68,000 lb.

Length - 45 to 65 feet

Width - 96 inches

Deck Height - 59 inches

Overall Height - 119 inches at Headboard

Axles - 20,000 lb. Rockwell, two (2) each

Service Brakes - Full Air, S-cam, with one Bendix No.

RE-6 Relay Emergency Valve only.

Note: There is no trailer spring brake valve installed on these trailers, of any kind; and only one (1) air reservoir.

Parking Brakes - MGM Spring Applied, Air Released

Trailer Serial Nos: 1GRDM8025KM013401

1GRDM8027KM013402

1GRDM8029KM013403

1GRDM8020KM013404

Attached is a copy of the SRP Vehicle Data Record for one of the trailers, and a "line set" sheet supplied by Great Dane Trailer for one of the trailers.

These four trailers are identically equipped.

Specifically, SRP is concerned that these trailers do not comply with the law, and leaves SRP open to litigation should an accident and resulting lawsuit arise, because of noncompliance in the area of S5.2.1.1 that trailers must have a reservoir that "is capable, when pressurized to 90 p.s.i., of releasing the vehicle's parking brakes at least once and that is unaffected by loss of air pressure in the service brake system"; and S5.2.1.5 that states "be protected against loss of air pressure due to failure or leakage in the system between the service reservoir and its source of air pressure by check valves or equivalent devices". We are aware of Docket 90-3 Notice 2 (corrected to Notice 3 by Notice 4) which revises a portion of FMVSS 121, but do not know the affect it will have on our concerns.

Attachments: SRP Vehicle Data Record

Great Dane Line Set Sheet (TEXT AND PHOTOS OMITTED)