Interpretation ID: nht81-2.14

DATE: 04/14/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Seats Inc.

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your March 20, 1981, letter asking about the seat belt testing requirement applicable to seat belts mounted on a seat frame in a school bus.

You state that it is your understanding that seat belts that are mounted on a seat frame in a school bus are not required to be tested simultaneously, because the seat is not considered to be a common mounting. Further, you state that if the seat belts mounted on the frame use a common anchorage, either a common anchorage hole or a U-bolt connecting the two belts, that they would be required to be tested simultaneously.

Your interpretation of Standard No. 222 as it relates to school buses is correct. We would emphasize that this interpretation for the testing of seat mounted seat belts applies only to school buses.

SINCERELY,

Seats

March 20, 1981

Mr. Frank Berndt U.S. Department of Transportation National Highway Traffic Safety Administration

Dear Mr. Berndt:

Reference: NOA-30

As a final effort to end all misinterpretations of your Department's stand on FMVSS 222, School Bus Passenger Seating and Crash Protection, seat belt requirements; I reference past communication with your department, copies enclosed, on the subject of common and separate mounting and the effect a U-bolt mounting has on the Department's interpretation to common mounting and test requirements. Communications referenced are:

A. Your Department's interpretation to Wayne Corporation, dated March 25, 1977 (Enclosure A)

B. Letter to Mr. Roger Tilton, dated October 31, 1980 (Enclosure B)

C. Your Department's letter NOA-30, dated December 2, 1980 (Enclosure C)

I understand, in layman's language, so all can have, without doubt, the same understanding of the following, that individual seat belt anchorage testing is required as long as each seat belt system has its own anchorage points.

Therefore, the simultaneous testing is totally dependent on the interpretation of common anchorage of two seat belt systems on a two-passenger seat assembly.

It is further my interpretation that the metal seat frame or supporting structure is not considered a common anchorage point, that each seat belt system being attached to the seat frame by its own bolts and nuts, one set for each end of the seat belt system, is not considered common anchorage; and therefore, does not require simultaneous testing of the two seat belt systems, but independent tests of 5,000 pounds. However, if any part of the two seat belt systems are attached by a single bolt and nut on the inside portions or the use of a U-bolt so that the same attaching hardware comes in contact with more than one seat belt system, it is considered a common anchorage point and thus requires simultaneous testing of 5,000 pounds for each seat belt system for a total force of 10,000 pounds.

If you concur with my interpretation on this matter, please sign one copy in the space provided and return to me for my records file.

Harold J. Van Duser Engineering

Mr. Frank Berndt U.S. Department of Transportation