Interpretation ID: nht74-1.31

DATE: 02/26/74

FROM: CERSAS FOR E.T. DRIVER, NHTSA

TO: Mack Trucks, Inc.

COPYEE: J. LEYSATH; MR. VINSON

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 4, 1974, concerning the location requirements of front identification lamps on certain solid-waste disposal vehicles.

You describe the vehicles in question as "short BBC low cab-ever-engine type vehicles -- equipped with a large volume body and a hydraulically operated front leader mechanism. This unit lifts containers of waste up and over the front of the cab and empties the waste into the top of the body. To prevent damage to the front of the vehicle and lamps, a protective guard is installed on the front centerline of the vehicle." You further state that "This guard could obstruct the center identification lamp."

You ask whether or not all three of the front identification lamps may be offset from the front centerline of the vehicle to ensure compliance with the visibility requirements of FMVSS No. 108. In accordance with paragraph S4.3.1. Table II of FMVSS No. 106 specifies that the front identification lamps be located "as close as practicable to the top of the vehicle, at the same height, as close as practicable to the vertical centerline." For the vehicles which you have described, it would appear that location of the front identification lamps either left or right of the vertical centerline would meet this requirement.

Sincerely,

ATTACH.

February 4, 1974

E.T. Driver -- National Highway Traffic Safety Administration, Office of Operating Systems

Dear Mr. Driver:

Subject: Request for Interpretation MVSS 108

Section S4.1.1 table I states that three identification lamps are required for vehicles of 80 or more inches overall width.

Section S4.3.1 table II requires that "three amber identification lamps be located on the front as close as practicable to the top of the vehicle, at the same height, and as close as practicable to the vertical centerline".

In addition, Section S4.3.1.1 requires that each lamp be located so that it meets the visibility requirements of applicable SAE Standards and that no part of the vehicle shall prevent the device from meeting the photometric output at any test point specified in any applicable SAE Standard.

Section S4.3.1.1 also states that if motor vehicle equipment prevents compliance, an auxiliary lamp or device meeting the requirement shall be provided.

The solid waste disposal industry use short BBC low cab-over-engine type vehicles (see Attachments 1 & 2) equipped with a large volume body and a hydraulically operated front loader mechanism. This unit lifts containers of waste up and over the front of the cab and empties the waste into the top of the body. To prevent damage to the front of the vehicle and lamps, a protective guard is installed on the front centerline of the vehicle. This guard could obstruct the center identification lamp. (See Attachment 3 through 6)

One of our customers has requested that we supply four identification lamps on the forward side of our MB series vehicle cab near the top so that he can mount a protective guard on the centerline of the cab and still meet the visibility and photometric requirements.

As we discussed during my visit of January 31st, use of four lamps will not be acceptable to the National Highway Traffic Safety Administration as it would defeat the identification function of these lamps for vehicles over 80" in width.

However, it was proposed that all three identification lamps could be moved to one side of the centerline, thereby permitting compliance with the visibility and photometric requirements when the units are in the installed position. This appears to us to be an effective solution to this problem and we, therefore, request your issuance of an interpretation for an installation of this type.

Very truly yours, MACK TRUCKS, INC.; A. M. Fischer -- Asst. to Exec. V.P.- Engineering & Product

Enclosure Omitted.