Interpretation ID: 77-3.48

TYPE: INTERPRETATION-NHTSA

DATE: 08/18/77

FROM: AUTHOR UNAVAILABLE; Joseph J. Levin Jr.; NHTSA

TO: Walker Stainless Equipment Co.

TITLE: FMVSR INTERPRETATION

ATTACHMT: 5/11/77 Letter from Walker Stainless Equipment Co. to NHTSA

TEXT: This is in response to your letter of May 11, 1977, and your subsequent conversation with Roger Tilton of my staff, concerning the certification of tank type vehicles. You suggest that a vehicle certification label as specified in 49 CFR Part 567, Certification, be required to state the gross vehicle weight rating (GVWR) and the gross axle weight rating (GAWR) in pounds.

You apparently have misinterpreted our regulations to require that the GVWR and the GAWR be in something other than pounds where a vehicle is designed to carry liguids. Since the density of liquids is not constant, the weight of customary liquid measurements would depend upon the type of liquid being carried. Since liquid measurements have no precise weight value, designating load ratings by those measurements would not ensure that vehicles would not be overloaded. It has always been the policy of the National Highway Traffic Safety Administration to require that the GAWR and the GVWR be stated in pounds.

Title 49 CFR Part 568 prescribes the method by which manufacturers of vehicles manufactured in two or more stages must ensure conformity with the Federal motor vehicle safety standards. A final-stage manufacturer is described as one who "performs such manufacturing operations on an incomplete vehicle that it becomes a completed vehicle." Both "incomplete vehicle" and "completed vehicle" are defined in Section 568.3 of the regulation.

Section 568.6 of Title 49 requires each final-stage manufacturer to certify that the entire vehicle conforms to all applicable standards, in accordance with Section 567.5. That section requires each final-stage manufacturer to affix a label to the vehicle containing, among other things, the GVWR and the GAWR. The GVWR is the value in pounds, which is not less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the vehicle's designated seating capacity. The GAWR is the value specified by the vehicle manufacturer as the load-carrying capacity of a single axle system, as measured at the tire-ground interfaces.

When a vehicle is manufactured in two or more stages 49 CFR 568.4 requires the incomplete manufacturer to furnish with the incomplete vehicle a document containing the GVWR and GAWR for the completed vehicle for which the incomplete vehicle is intended. These ratings are generally used by the final-stage manufacturer in certifying the vehicle. If he chooses to exceed the stated GVWR and GAWR ratings he must also certify that the vehicle will continue to meet all applicable motor vehicle safety standards.

It is the cargo load rating that is most relevant to the problem of overloading. The rated cargo load should represent the manufacturer's assessment of the vehicle's cargo-carrying capacity and the maximum load at which the vehicle may be safety operated. A manufacturer must consider the maximum load capacity of the vehicle when it designs its cargo-carrying portion. If this is not done, the rated cargo load, and thus the GVWR, may be meaningless since the vehicle may have a cargo-carrying chamber which, if filled, would cause the vehicle to exceed its stated weight ratings. An illustration of such a situation would be a tanker truck which exceeds its GVWR when the tank is filled with a type of material appropriate for carrying in that cargo area. If the manufacturer could reasonably have anticipated that such cargo would be carried in the tanker, yet rated the vehicle with a GVWR which was less than the vehicle's weight when fully loaded with that cargo, a safety-related defect for which the manufacturer is responsible may be considered to exist.

The NHTSA does not expect manufacturers to be omniscient when it comes to the use of the vehicles they produce. It does, however, except the stated weight ratings to reflect the design of the vehicles and the uses to which they can reasonably be anticipated to be put. Where the manufacturer has reason to know the specific commodity intended to be carried in its vehicles and those vehicles have a totally enclosed cargo area, as with a tanker, the rated cargo load is relatively easy to determine.

In your particular case, your responsibility for any subsequent overloading of the vehicles you manufacture would be determined by the reasonableness of your GVWR's and GAWR's, given the size and configuration of your vehicles and the types of loads which they could reasonably be expected to carry. In the case of flat beds (no enclosed cargo area) a manufacturer would obviously not be able to provide weight ratings sufficiently high to prevent over-loading in all instances. The design of flat beds necessarily permits overloading since the cargo area is unrestricted. Thus if the weight ratings specified appear to have been arrived at by a good faith determination based upon the types of loads the manufacturer anticipates will be carried, its responsibility with regard to weight rating specifications will have been satisfied and no safety-related defect will be attributable to it.