Interpretation ID: nht74-1.49

DATE: 05/10/74

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

TO: Superior Trailer Works

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your April 22, 1974, question concerning the certification responsibility of a small manufacturer of trailers that must conform to Standard No. 121, Air brake systems. You ask if road testing of any or all vehicles produced would be necessary to satisfy the requirements.

A manufacturer must "exercise due care" in certifying that the vehicles manufactured by him comply with the applicable standards (National Traffic and Motor Vehicle Safety Act of 1966, @ 108(b)(2), 15 U.S.C. @ 1392(b)(2)). What constitutes due care in a particular case depends on all relevant facts, including such things as the time to elapse before a new effective date, the availability of test equipment to small manufacturers, the limitations of current technology, and above all the diligence evidenced by the manufacturer.

A small manufacturer of standard and custom trailers might fulfill his due care responsibility to assure that each of his trailers is capable of meeting the standard in several ways. For example, he could establish categories of models which share a common brake and axle system and certify them all on the basis of tests on the most adverse configuration in the category. Calculations should be written down in such a case to establish that reasonable care was taken in these decisions.

Alternatively, joint testing might be undertaken with a trade association or with a major supplier of brake and axle components. In the case of standard models, you might be able to rely on the supplier's warranty of his products' capacities.

Neither of these methods would require road testing of each vehicle manufactured, nor would every model have to be road tested. A manufacturer must simply satisfy himself that the trailer is capable of meeting the stopping performance requirements if it were tested by the NHTSA.

Yours truly,

ATTACH.

April 22, 1974

National Highway Traffic Safety Administration Attn: James B. Gregory, Administrator

Gentlemen:

We are a small trailer manufacturing firm currently producing approximately 100 trailers per year. These trailers are predominantly standard models (with some variations in body length and height), however, we also manufacture some custom trailers, principally low beds.

We do not manufacture brakes or axles or air system components, instead we purchase a complete axle-brake assembly and the air components, and assemble them into a trailer chassis. Under the Motor Vehicle Safety Standard 121 we will, of course, install components that meet the new requirements.

We are in the process of determining all the changes that we will be required to make under MVSS 121 and would appreciate clarification of the following:

1. Will we be required to road test complete trailers or will the inclusion of all certified components satify the requirements of the law?

2. If road testing of the complete trailer is required, is it required of every trailer produced, or would the test of a single prototype of a standard model be sufficient for all other trailers of the same model?

3. What road testing would be required for custom trailers that vary widely in length, width, height, capacity, etc.?

We have contacted several California trailer manufacturers, and they are in the same position that we find ourselves, i.e., no testing facilities of our own and without knowledge of any independent testing facility offering such a service. The size of the facilities required would make it all but impossible for any but a very large business firm to construct a special facility.

We are including some literature that will show the variations in equipment that we manufacture.

Your earliest possible comments would be greatly appreciated.

Very truly yours,

SUPERIOR TRAILER WORKS Charles R. Richards -- President