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Interpretation ID: 77-2.1

TYPE: INTERPRETATION-NHTSA

DATE: 03/25/77

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Wayne Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your oral request of February 17, 1977, for an interpretation of the requirements of Standard No. 210, Seat Belt Assembly Anchorages, as they apply to Standard No. 222, School Bus Passenger Seating and Crash Protection. In particular, you ask how much force must be used when testing school bus seat belt anchorages for compliance with the standards.

As you may know, the National Highway Traffic Safety Administration, initially proposed that seat belt anchorages be installed in all school buses. At that time, we also proposed that each seat belt assembly be tested under a force of 1,500 pounds. A seat containing three seating positions would have had the three seat belt assemblies tested simultaneously with a possible resulting load upon the seat of 4,500 pounds. The requirement of seat belt anchorages in larger buses was dropped from the proposal based upon comments from school bus operators and as a result of our compartmentalization approach to passenger seating safety in school buses.

The present Standard No. 222 requires seat belts and anchorages in small buses and mandates testing of the anchorages as outlined in Standard No. 210. Standard No. 210 requires in S4.2.1 that each seat belt assembly sustain a force application of 5,000 pounds. Where two adjacent seating positions have a common seat belt anchorage mounted on a seat frame, the two seat belt assemblies must simultaneously sustain a 5,000 pound force for a maximum load on the seat of 10,000 pounds.

Standard No. 207, Seating Systems, requires the simultaneous testing of all seat-mounted seat belt assemblies, whether or not they have common anchorages. However, Standard No. 207 is not applicable to school bus seats constructed in accordance with Standard No. 222, and it is not necessary to test simultaneously all seat belt assemblies attached to anchorages mounted on a school bus seat frame.