Interpretation ID: nht79-1.35

DATE: 03/22/79

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: The Grote Manufacturing Co.

TITLE: FMVSS INTERPRETATION

TEXT:

MAR 22 1979 NOA-30

Mr. C. J. Newman Vice President, Engineering The Grote Manufacturing Company State Route 7, P.O. Box 766 Madison, Indiana 47250

Dear Mr. Newman:

This is in reply to your letter of February 15, 1979, asking for an interpretation of S4.3.1.1.1 of Motor Vehicle Safety Standard No. 108.

You have informed us that dimensional changes in refrigeration units on the front of commercial trailers mean that clearance lamps are no longer visible at 45 degrees inboard if they are mounted as they have been in the past. You have proposed three alternate solutions to the problem.

S4.3.1.1.1 provides in pertinent part that "clearance lamps may be mounted at a location other than on the front and rear if necessary to indicate the overall width of the vehicle...and at such a location they need not be visible at 45 degrees inboard." Your first proposed solution is that "The lamps could be mounted on the front of the vehicle as normal and the 45 degree inboard visibility requirements waived in accordance with S4.3.1.1.1."

We believe that this is preferable to your other suggested solutions that utilize angle-mounted combination lamps. Standard No. 108 appears to prescribe alternate requirements for location and visibility of clearance lamps--preferably on the front and visible throughout 45 degree angles, but if not, elsewhere than the front and where they need not be visible through the 45 degree angles. Your first proposed solution comprises elements of each of Standard No. 108's alternatives, and while it is not expressly permitted by Standard No. 108, it does not appear to violate it.

Sincerely,

Frank Berndt Acting Chief Counsel

February 15, 1979

U. S. Department of Transportation National Highway Traffic Safety Administration Washington, DC 20590

Attn: Mr. J. J. Levin, Jr. Chief Counsel

Dear Sir:

Recently there have been dimensional changes in the refrigeration units used on the front of commercial trailers and these new dimensions restrict the visibility of the front clearance lamps. These new refrigeration units are up to 80 inches wide, 83 inches high and extend out from the front of the trailer up to 23 inches. These larger units restrict the mounting location of the clearance lamps on the front of the vehicle.

With this obstruction the in-board 45o visibility angle cannot be met if the clearance lamps are mounted as they normally have been.

Section S4.3.1.1.1 of Federal Motor Vehicle Safety Standard states, "Clearance lamps may be mounted at a location other than on the front and rear if necessary to indicate the overall width of the vehicle, or for protection from damage during normal operation of the vehicle, and at such a location they need not be visible at 45o in-board".

Our interpretation of Section S4.3.1.1.1 would allow for three possible solutions to the problem described earlier.

The methods are as follows:

1. The lamps could be mounted on the front of the vehicle as normal and the 45o in-board visibility requirements waived in accordance with Section S4.3.1.1.1. See Sketch #1.

2. A combination lamp meeting the requirements of both a side marker lamp and a clearance lamp mounted at 45o could be installed on the corner of the trailer and again the 45o in-board visibility requirements waived in accordance with Section S4.3.1.1.1. See Sketch #2.

3. The front clearance lamps could be omitted completely from the front of the trailer and a lamp meeting the combination requirements for a side marker and clearance lamp could be mounted on the side of the trailer at the front. This lamp would then meet the requirements for a side marker lamp having 45o visibility each side of the center line and having light directly to the front of the vehicle. The 45o in-board visibility requirements would again be waived in accordance with Section S4.3.1.1.1. See Sketch #3.

Before making any recommendations to our customers regarding the possible solution to this problem, we would like to have your comments.

Yours very truly,

THE GROTE MANUFACTURING COMPANY

C. J. Newman Vice President, Engineering

CJN/aj

Encl.