Interpretation ID: nht79-4.45

DATE: 01/11/79

FROM: AUTHOR UNAVAILABLE; Joseph J. Levin, Jr.; NHSTA

TO: Grumman Flxible

TITLE: FMVSS INTERPRETATION

TEXT:

U.S. DEPARTMENT OF TRANSPORTATION NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION WASHINGTON, D.C. 20590

JAN 11 1979

NOA-30

Mr. R. L. Ratz, P.E. Product Safety Engineering Grumman Flxible 970 Pittsburgh Drive Delaware, Ohio 43015

Dear Mr. Ratz:

This is in reply to your letter of December 8, 1978, asking whether the front and rear clearance lamps on your Model 870 Urban transit coach comply with Federal Motor Vehicle Safety Standard No. 108.

The front clearance lamps on the Model 870 are combined with the turn signal lamps, side marker lamps, and side reflex reflectors. The units are located "on line with and just outboard of each rectangular headlamp," with lens center 32 inches above the road surface, at a point that appears to be at the vehicle's overall width. The rear clearance lamps are combined with the stop lamps and rear side marker lamps, their horizontal center lines 64 inches above the road surface, at approximately the vehicle's overall width. Front and rear identification lamps are mounted at the top of the vehicle.

The general rule expressed by Table II of Standard No. 108 is that clearance lamps must be mounted "to indicate the overall width of the vehicle ... and as near the top thereof as practicable." But a partial exception is provided by S4.3.1.4.: When the rear identification lamps are mounted at the extreme height of the vehicle, rear clearance lamps need not meet the requirement of Table II that they be located as close as practicable to the top of the vehicle."

This means that the mid-body location of the rear clearance lamp is acceptable since the rear identification lamps are at the extreme height of the vehicle. But the exception does not extend to the front clearance lamps. While Standard No. 108 allows the manufacturer to determine what location is "as close as practicable to the top of the vehicle", there will be instances when the overall width of the vehicle will not be indicated by the highest location. In such instances the best location will be the one that most closely approximates the intent behind the requirement - to indicate the overall width.

Specifically with reference to the Model 870, it appears to us that the close proximity of the combination lamp to the headlamp may result in the effectiveness of the clearance lamp being impaired by the brightness of the headlamp, and that the most practicable location sufficiently indicating the overall width of the vehicle, would be at the outer edges of the body directly below the windshield.

Sincerely,

Joseph J. Levin, Jr.

Chief Counsel

GRUMMAN FLXIBLE 970 PITTSBURGH DRIVE DELAWARE, OHIO 43015 614/369-7671 Telex : 245484 70-0220rlr

December 8, 1978

Office of Chief Counsel National Highway Traffic Safety Administration 400 Seventh Street S.W. Washington, D.C. 20590

References: (a) FMVSS No. 108. Lamps, Reflective Devices, and Associated Equipment, current edition. (b) Grumman flxible Model 870 Advanced Design Transit Coach, photographs attached. (c) Certificates of conformance copies attached.

Dear Sirs:

Your assistance is requested with respect to an official interpretation of reference (a) above as it relates to the installation location of the clearance lamps on our new Grumnan Flxible Model 870 urban transit coach as shown in the enclosed photographs.

Refering to Photograph #1, the amber lamp seen on line with and just outboard of each dual, rectangular headlamp is a combination lamp which performs the functions of a turn signal lamp, a clearance lamp, a sidemarker lamp and a side reflex reflector. The lamp contains a single, dual-filament bulb. A 3 c.p. filament provides the light source for the combination clearance/sidemarker lamp functions. and a 32 c.p. filament provides the light source for the front turn signal function. This lamp has been certified as being in conformance with FMVSS No. 108 by the manufacturer (See Attachment #1) and certificates of approval have been issued by the American Association of Motor Vehicle Administrators (See Attachment #2) and the Department of California Highway Patrol (See Attachment #3). These lamps are mounted with lense centers 32 inches above road surface, on the outermost edges of the vehicle front view envelope thus indicating the overall width of the Model 870. It should be noted from Photo #1 that the vehicle sides converge from a point just beneath the baseline of the windshield up to the topmost roof corners. The amount of this convergence is such that each roof corner is eleven inches inboard if the base of the windshield cornerpost. Therefore, clearance lamps mounted at the top-most roof corners would identify the vehicle as being twenty-two inches narrower than it actually is.

Our rear exterior lamp configuration is shown in Photo #4. The upper red lamp on each outer edge of the rear view functions as a stop signal lamp, a clearance lamp and a sidemarker lamp. The horizontal center line of this lamp as installed is 64 inches above road surface. The lower red lamp functions as a tail lamp, a turn signal lamp, rear reflex reflector and a side reflex reflector. It's horizontal center line as intalled is 50 inches above road surface. Each lamp contains a single, dual-filament 3 c.p. & 32 c.p.) bulb. The stop signal and turn signal functions utilize the 32 c.p. filament. The clearance, sidemarker and tail lamp functions utilize the 32 c.p. filament.

The white lamp shown between the two red lamps on each side are backup lamps. Attachments #4, #5 and #6 are copies of the certificates associated with these lamp units.

We would greatly appreciate a review and evaluation by the Office of the Chief Counsel, National Highway Traffic Safety Administration, of the installation locations of the clearance lamps on the Model 870 bus as regards to conformance with the applicable requirements of FMVSS No. 108.

Sincerely,

R.L. Ratz, P.E.

Product Safety Engineering

Enclosures