Interpretation ID: 1985-03.21

TYPE: INTERPRETATION-NHTSA

DATE: 07/24/85

FROM: AUTHOR UNAVAILABLE; Jeffrey R. Miller; NHTSA

TO: Thomas J. Moravec -- President, Tow-All, Inc.

TITLE: FMVSS INTERPRETATION

TEXT:

Mr. Thomas J. Moravec President Tow-All, Inc. 10501 E. Bloomington Freeway Bloomington, MN 55420

This responds to your letter of May 20, 1985, concerning Federal requirements applicable to the motorized hitch or "Supplemental Power Unit" (SPU) being developed by your company.

This agency administers the National Traffic and Motor Vehicle Safety Act of 1966, as amended, 15 U.S.C. 1391 et seq. (the Act). Under the Act, a motor vehicle is defined as "any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads and highways." Your letter states that the SPU is a motorized single axle unit with an automatic transmission. In addition, your letter, the accompanying photographs, and descriptive material indicate that the SPU could be attached between a small car and a large trailer to permit the small car to safely pull the trailer long distances at highway speeds.

Based on this information, the agency concludes that the SPU is a motor vehicle and falls within the trailer classification. Under 49 CFR Part 571.3, a trailer is defined as "a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another vehicle." An information sheet for manufacturers is enclosed.

The following regulations and Federal motor vehicle safety standards are applicable to trailers:

49 CFR Part 565, Vehicle Identification Number Content Requirements 49 CFR Part 566, Manufacturer Identification 49 CFR Part 567, Certification (see S567.4 for trailers) Standard No. 106, Brake Hoses Standard No. 108, Lamps, Reflective Devices and Associated Equipment Standard No. 115, Vehicle Identification Number Basic Requirements Standard No. 116, Motor Vehicle Brake Fluids Standard No. 119, New Pneumatic Tires for Vehicles Other Than Passenger Tires Standard No. 120, Tire Selection and Rims for Vehicles Other Than Passenger Tires Standard No. 121, Air Brake System

Copies of these regulations and standards can be obtained by writing to: Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. An information sheet for ordering copies is also enclosed.

State regulations applying to trailers and their use on the roads should be checked for any State in which your company's trailers are to be sold.

I hope this information is helpful to you.

Sincerely,

Jeffrey R. Miller Chief Counsel

Enclosures

May 20,1985

Office of Chief Council National Highway Traffic Safety Administration 400 Seventh Street S.W. Washington, D.C. 20590

Dear Sirs:

This letter is a formal request for the evaluation as to which federal statutes of the National Highway Traffic Safety Administration are applicable to a new motorized road vehicle product that we are developing at TOW-ALL, Inc. As I discussed recently over the phone with Mr. Ralph Hitchcock of the Office of Vehicle Safety Standards, we are developing a revolutionary new product: the Supplemental Power Unit (SPU) or "Motorized Hitch". Inclosed are brochures which describe this concept, our first working prototype, and pictures of this prototype. Also inclosed are copies of two patents we own on this concept which may be helpful in understanding the operation of the SPU.

Basically, the SPU is a motorized single axle unit that attaches between a small car (e.g. a Chevette) and a large trailer (e.g. a 24 foot camper trailer) that allows the small car to safely pull the trailer for long distances at freeway speeds. This is explained in detail in the attached documents. I realize that this is a new idea and thus may not fall directly under specific legislation. The purpose of this letter is to determine which federal laws will be interpreted as being applicable.

We intend to manufacture the SPU out of new parts manufactured in the United States and market the unit worldwide. If you have further questions, please contact me at (612)-8818996 or write me at the above address.

Sincerely yours,

Thomas J. Moravec President TOW-ALL, Inc.

THE SUPPLEMENTAL POWER UNIT "MOTORIZED HITCH"

A vehicle of any size, particularly small, could be enabled to tow a large trailer if this trailer could become self propelled. This note describes a novel method for providing this ability for towing the desired trailer. There are at least two primary requirements for pulling all trailers. First, the towing vehicle must have sufficient power to propel both vehicles, and second, the towing vehicle must be able to carry the tongue weight of the trailer. Few automobiles manufactured today and almost no small cars can meet these requirements.

The novel method that this paper is suggesting for solving this problem is what is called the supplemental power unit (SPU). It is also referred to as a "motorized hitch". This SPU is a small motorized trailer which is attached between the towing vehicle and the trailer that is desired to be moved. The motorized SPU has an automatic transmission and a gas or diesel engine. The synchronization of movements of the vehicle combination is provided by the hitching and towing system for the SPU.

The SPU is rigidly attached to the trailer that is to be pulled and pivoted or articulated vertically about the hitch between these two trailers. The SPU now carries all of the pulled trailer's tongue weight and provides the power to pull this trailer combination. The SPU can be manufactured in a number of sizes to meet the range of towing and tongue weight requirements of the consumer, commercial, and agricultural markets.

The rigid connection between the two trailers permits the tongue of the SPU to be hinged about a horizontal axis so no tongue weight or braking or acceleration moments are applied to the lead vehicle. A portion of the physical weight of the tongue (25-40 lbs.) is all the weight the tongue applies. The operation of the control mechanism of the SPU can also easily be reversed to give power and braking in the reverse direction. When towing a trailer, the tongue weight is generally added to the rear of the towing vehicle. This loading can be distributed over the whole vehicle by "load leveling hitches". These are complicated to couple and disconnect. If no "load leveling" is used and tongue weight is high, the traction of the front wheels and steering can become effected particularly in rough terrain. The SPU applies a very small load (25-40 lbs.) to the rear of the towing vehicle and is very easy to couple and uncouple. In general the towing vehicle does not sense the load being pulled with the SPU attached.

Attachment of the SPU to the load trailer is relatively simple. The patented control arm is hooked to the trailer ball of the front vehicle. No other connections are required. Once attached, the load trailer can be moved using the SPU to another location if desired using just its own power if the terrain is not too irregular. The power disc brakes on the SPU greatly aid in stopping the load trailer due to the method of attachment between the trailers and because of the load transfer which is automatically produced by the braking process.

The tongue of the SPU is hinged about a horizontal axis. This feature prevents the transfer of any of the tongue weight during transit and greatly facilitates coupling. Also, when this tongue is detached from the towing vehicle and allowed to hang down, it applies the brakes of the SPU. This feature is particularly useful if using the SPU to move the load trailer by hand.