Interpretation ID: nht72-4.48

DATE: 12/13/72

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Trailmobile

TITLE: FMVSR INTERPRETATION

TEXT: This is in reply to your letter of November 3, 1972, in which you ask whether a Certification label, a drawing (33-1-78) of which you enclose, will meet both the requirements of the Certification regulation (49 CFR Part 567) and those of proposed Motor Vehicle Safety Standard No. 120. "Tire and Rim Selection and Rim Performance" (36 F.R. 142730). In our conversation of November 28, 1972, you asked two additional questions -- first, whether GAWR for trailers could be expressed as a single figure when the ratings for each axle are identical, and second, as followed up by your letter of November 30, what is the appropriate method for determining GVWR for a semitrailer having a "sliding-bogie" axle.

The Certification label you have submitted would conform to the requirements of Part 557, and proposed Standard No. 120 if "rim size" is moved from its location following GAWR and GVWR to the bottom of the label, in proximity to the "maximum rim load rating." The Certification regulation does not require rim size to be specified, and rim size would therefore have to appear after the information required by that regulation. The requirements of proposed Standard No. 120 are tentative only, as you must know, and manufacturers should not make permanent plans regarding them until a final rule is issued.

The NHTSA position with respect to GAWR being expressed as one figure when identical axles are involved is that such a method is not consistent with the Certification regulation. Each axle must be listed separately on the Certification label regardless of whether its rating is identical to that of other axles. We have no record of any oral statement to the contrary, and if one was made, as you seem to recall, we regret that it was in error. With respect to specifying GVWR for trailers having sliding-bogie axles, the NHTSA position is that a manufacturer is free to assume the axle to be in either position. If the manufacturer wishes to indicate at which position the rating is based, he may do so on the label, following all required information.