Interpretation ID: nht75-4.1
DATE: 11/17/75
FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA
TO: MOTAC, Inc.
TITLE: FMVSS INTERPRETATION
TEXT: This responds to MOTAC's September 18, 1975, question whether rebuilding a platform trailer constitutes the manufacture of a new vehicle subject to applicable motor vehicle safety standards when the running gear (the axles, wheels, suspension, and related components sometimes known as a bogie) and the platform of a wrecked trailer is used (1) in combination with entirely new frame members, (2) in combination with one main frame member of the wrecked vehicle and one new frame member, and (3) in combination with part of one or both main frame members. You also ask whether the addition of a second axle to a single axle trailer, or the deletion of one axle on a tandem axle trailer, qualifies as the manufacture of a new vehicle subject to applicable safety standards.
In response to your first question, the National Highway Traffic Safety Administration (NHTSA) has determined (in the Stainless Tank and Equipment letter to which you refer) that, as a minimum, the running gear and main frame of the existing trailer must be used to qualify the rebuilding operation as a repair where all other materials are new. This position does not apply to the three situations you describe in which only the main frame members, and perhaps several cross members, are replaced. Therefore a repair of this type is not considered the manufacture of a new trailer.
In response to your second question, the NHTSA would not consider the addition of a second axle to a single axle trailer, or the removal of one axle from a tandem axle vehicle, to constitute the manufacture of a new vehicle.
Sincerely,
September 18, 1975
National Highway Traffic Safety Administration
Attention: Frank A. Berndt Acting Chief Counsel
We would appreciate your clarification as to the extent that major repairs and/or modifications may be made to semi-trailers and pull trailers without the inclusion of the FMVSS 121 anti-lock brakes.
We have two items or catagories that we wished resolved and they are brought about thru your letter of 8/28/75, file number N40-30 addressed to Stainless Tank and Equipment, Inc., Cottage Grove, Wisconsin. This letter was transmitted to all members of T.T.M.A.
ITEM NO. 1
Assume that a platform trailer had been in a serious accident and possibly rolled over, thereby bending and twisting the main frame members severely. We will also assume that the damage is to such an extent that the main frame members cannot be straightened, which generally can be done.
The following conditions could then prevail for the required repair:
A. Cut the damaged portion off of one or possibly both main frame rails and repair with a new partial section or sections.
B. Replace one main frame rail completely.
C. Replace both main frame rails completely.
In the above hypothesis, the "Bogie", axles, wheels, tires, supports, etc. would all be used. The trailer would maintain the same model and serial number.
In a major repair of this sort will the standard 121 brakes be required? If so, then the old axles would have to be junked and new S-121 axle assemblies with computor/relay valves must be purchased and installed.
ITEM NO. 2
Six years ago, our company manufactured thirty (30) single axle container semi-trailers and thirty (30) tandem axle container semi-trailers, 25 foot long to haul 20 foot containers. The main frame rails, bolsters, supports, etc., are identical on both trailers.
The customer is now contemplating converting the single axle semi-trailers to tandem axle semi-trailers. This will entail relocating the existing front and rear spring hangers, adding a center equalizer hanger and rocker arm assembly, one set of springs, one axle, brake, tire and wheel assembly. The trailer will be reregistered as a tandem axle semi-trailer for state licensing.
In converting a single axle semi-trailer to a tandem axle semi-trailer will the Standard 121 brakes be required? Also, conversely, if a tandem axle semi-trailer should be converted to a single axle semi-trailer will the Standard 121 brakes be required?
MOTAC, INC.
Jack A. Johnson Chief Engineer