Interpretation ID: aiam2374
Jr.
Product Engineering and Development
Volvo of America Corporation
Rockleigh
NJ 07647;
Dear Mr. Gobeille: This is in response to your April 6, 1976, request for interpretation regarding certain sections of Safety Standard No. 209, *Seat Belt Assemblies*, when applied to the continuous loop seat belt assemblies provided on current Volvo vehicles.; Paragraphs S4.4(b)(1) and (2) specify performance requirements fo components in the pelvic restraint and upper torso restraint portions of a belt system, tested separately and in combination. You ask for verification of your interpretation that the requirements for separate testing of pelvic and upper torso portions are inapplicable to a continuous loop seat belt, on the basis that this type system can never in real life be subjected to forces only in the pelvic restraint.' Your letter includes an illustration of your test apparatus for determining compliance with paragraph S4.4(b), and you request verification that your procedure is correct.; Section S5.3(b) of the standard sets forth the test methods that woul be used in a determination of whether a Type 2 seat belt assembly conforms to the requirements of S4.4(b). Paragraph S4.4(b)(1) specifies that the pelvic restraint shall withstand a force of not less than 2,500 pounds, and S4.4(b)(2) specifies that the upper torso restraint shall withstand a force of not less than 1,500 pounds. The Volvo continuous loop belt systems are subject to these requirements. A recent NHTSA interpretation letter to Toyo Kojyo (copy enclosed) on the same subject sets forth the responsibilities of the manufacturer in cases where the specified test procedures may not be entirely suitable to a new safety component design. In testing continuous loop belt systems for compliance with S4.4(b)(1) and (2), the agency has interpreted S5.3(b) to necessitate the use of a clamp in the same fashion as suggested by Toyo Kojyo to ensure that the force is applied to the appropriate portion of belt webbing and hardware. It must be understood, of course, that the NHTSA cannot approve a manufacturer's test procedure as the basis of due care in advance of the actual events that underlie certification. It is impossible for the agency to foresee whether the various aspects of a particular test procedure will be conducted in a proper fashion, based solely on a written description of that test procedure.; In the second part of your letter you asked whether the buckle crus requirements of paragraph S4.3(d)(3) of Standard No. 209, when tested in accordance with the procedures specified in S5.2(d)(3), are applicable to Volvo seat belt buckles and, if so, whether Volvo's interpretation as to how the test should be conducted is correct.; It is true that the buckle requirements were originally included in th standard to guard against possible damage to the buckle caused by the steering wheel in a crash situation. Since the issuance of the standard, new seat belt assembly designs have been developed in which the belt buckle is located between the front seats. As you pointed out in your letter, these buckles are not likely to be contacted by the steering wheel in a crash situation.; In view of the significant design changes that have occurred, th agency has reconsidered its 1972 interpretation to United States Testing Company on this subject. Because it is unlikely that any of these buckles would be damaged by compressive forces in a crash, we have determined that the requirements are inappropriate. Therefore, we conclude that the existing S4.3(d)(3) buckle requirements are not applicable to buckles that are located between bucket seats and attached to the console or to the end of a rigid cable or bar.; Sincerely, Frank A. Berndt, Acting Chief Counsel