Interpretation ID: nht87-1.76

TYPE: INTERPRETATION-NHTSA

DATE: 05/17/87

FROM: AUTHOR UNAVAILABLE; Erika Z. Jones; NHTSA

TO: Mr. John B. Krueger

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. John B. Krueger Staff Engineer Society of Automotive Engineers, Inc. 3001 West Big Beaver, Suite 602 Troy, MI 48084

Dear Mr. Krueger:

This is in reply to your letter of February 10, 1987, asking the National Highway Traffic Safety Administration (NHTSA) to define the term "optically combined" as used in paragraph S4.4 of Federal Motor Vehicle Safety Standard No. 108. Presently, the SAE is circulating for comment its own proposed definition of the term, to be incorporated into SAE J387 Terminology - Motor Vehicle Lighting.

For many years paragraph S4.4 (your referenced S4.4.1 which was renumbered recently) has contained a prohibition against optically combining a clearance lamp with a taillamp or an identification lamp. NHTSA has provided written interpretations to those w ho have asked whether specific designs are "optically combined" within the meaning of paragraph S4.4, but the agency has not added a definition to paragraph S3, the definition section of the standard. If a definition is to be provided, it must be incorpo rated into the standard, and the agency is unable to do that without first formally proposing the definition and offering the public an opportunity to comment upon it. I can say, however, that the SAE's proposed definition is not inconsistent with the in terpretations of the agency.

These interpretations are available in the NHTSA docket room (Room 5109, 400 Seventh St., S.W., Washington, D.C.) for your reference should you or other SAE staff or committee members wish to examine them.

Sincerely,

Erika Z. Jones Chief Counsel

February 10, 1987

National Highway Traffic Safety Admin. Room 5219 400 Seventh Street, SW Nassif Building Washington, DC 205590

Attn: Ms . Erika Z. Jones. Chief Counsel

Dear Ms. Jones:

FMVSS 108 in paragraph 54.4. 1 includes the following statement ". . .no clearance lamp may be combined optically with any tail lamp or identification lamp". SAE standard J592, which is referenced by FMVSS 108, also contains this same prohibition against optically combining a clearance lamp with a tail lamp or an identification lamp.

There is a need to define the term "combined optically", and we respectfully request this definition from your office.

While this term has been a part of SAE documents for many years, unfortunately, there has never been a definition, and this is now needed to prevent abuses in the combining of these various lamp functions.

Canada has been concerned about the definition of this term for quite some time and has requested the assistance of the SAE Lighting Committee. Enclosed is a copy of a letter from Mr. J. G. White of Transport Canada on this subject and this includes the definition which Canada proposed in the July 12, 1986 issue of the CANADA GAZETTE on page 3244.

The SAE Lighting Committee is currently circulating the attached proposed definition for this term, and you will note that it is almost identical to the Canadian proposal.

A clear definition from the NHTSA would be appreciated by the SAE as well as the lighting industry.

Sincerely,

John B. Krueger Staff Engineer

Enclosure JBK. co

PROPOSED DEFINITION FOR ADDITION TO SAE J387 TERMINOLOGY - MOTOR VEHICLE LIGHTING

OPTICALLY COMBINED

A lamp shall be deemed to be "optically combined" if both of the following conditions exist:

A. It has two or more separate light sources, or a single light source that operates in different ways (e.g., a two filament bulb).

B. Its optically functional lens area is wholly or partially common to two or more lamp functions.

LABORATORY GUIDELINE - If two separate light sources each contribute some luminous flux to the function being tested, then both sources must be operating during a photometric test procedure.

Rationale: O In FMVSS 108, paragraph S4.4.1 , it is stated that ". .. .no clearance lamp may be combined optically with any tail lamp or identification lamp...." Similar wording occurs in subsection 14 of CMVSS 108.

For lack of this definition, lamps are being manufactured and installed on trailers that combine the tail and clearance lamp functions under one lens, with two closely-spaced bulbs. This clearly violates the spirit and intent of these safety standards.

O This definition harmonizes well with ECE Regulation 48, page 2, paragraph 2.6.5, " Reciprocally Incorporated Lamps."

O The following icons of the lighting fraternity have participated in the preparation of this definition: Paul Scully, Jim Wright, Warren Heath and Gordon Bonvallet.

SS3330-7-5 (DTSR/S)

Ottawa, Ontario, K1A ON5, October 28, 1986.

Mr. Paul Scully, Vice President, Peterson Manufacturing Company, 4200 East 135th Street, Grandview, MO 64030, U.S.A.

Dear Mr. Scully:

Thank you for sending me a copy of your letter

of August 5 to Bob Vile concerning the definition of "optically combined".

I think your proposal would do nicely. A definition much the same as the one you suggest in your letter has been included in the Canadian daytime running lights proposal, a copy of which is enclosed for your information.

I hope that "optically combined" can be included soon among the terms defined in SAE standards, and that producers of lamps with wrongly-combined functions will take note and correct their bad practices.

Yours very truly,

J.G. White, P. Eng., Head, Crash Avoidance Standards, Standards and Regulations, Road Safety and Motor Vehicle Regulation Directorate.

Encl. cc: R. Vile - N.A. Philips G. Wright - Fisher Guide A. Burgett - NHTSA

(SEE ATTACHMENT)