Interpretation ID: nht76-2.38

DATE: 10/08/76

FROM: AUTHOR UNAVAILABLE; S. P. Wood for F. Berndt; NHTSA

TO: Trailer Manufacturers Association

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of September 9, 1976, asking for an interpretation of two provisions of Motor Vehicle Safety Standard No. 108.

You have informed us that "some manufacturers are mounting lamps using lock washers and wing nuts rather than conventional nuts to facilitate the installation of lamps when boat trailers are assembled at the dealer level." S4.3.1 of Standard No. 108 requires that lamps "shall be securely mounted . . . ." and you asked whether wing nuts, used as you described, provide a mounting that complies with S4.3.1. The answer is that this would appear to provide a secure mounting within the intent of Standard No. 108.

S4.3.1.3 requires that front side marker lamps for trailers be located as far to the front as practicable, exclusive of its tongue. You ask whether "the tongue is considered to start where the trailer frame begins to angle inward from its parallel sides . . . ." The answer is yes.

I hope this clarifies Standard No. 108 for you and your members.

YOURS TRULY,

trailer manufacturers association

September 9, 1976

Frank Berndt Acting Chief Counsel U.S. Department of Transportation NHTSA

With regard to Federal Standard No. 108, confusion has arisen concerning the definitions or interpretation of several items in the standard upon which both ourselves, in the administration of our Trailer Certification Program, and our member manufacturers need an official interpretation.

1. S4.3.1 provides that lamps ". . . shall be securly mounted . . ." Some manufacturers are mounting lamps using lock washers and wing nuts rather than conventional nuts to facilitate the installation of lamps when boat trailers are assembled at the dealer level. When properly used, wing nuts provide a secure fastening, yet we have, informally, heard that they may not be considered as meeting S4.3.1. Do wing nuts, used as indicated above, provide a mounting in accordance with S4.3.1?

2. S4.3.1.3 provides for the location of front side marker lights as far forward as practicable exclusive of the trailer tongue. We have heard, informally, that NHTSA considers that the tongue is considered to start where the trailer frame begins to angle inward from the parallel sides, which location sometimes is quite far to the rear on a boat trailer. If this interpretation is correct, it considerably simplifies boat trailer wiring harnesses and may eliminate the need for angle brackets to mount from side marker lights where the frame is angling inward. Is the above interpretation correct? If not what is the proper interpretation of where the tongue is considered to start?

Executive Secretary DONALD I. REED