Interpretation ID: 18264-r.wkm

Mr. Mike Keenan
Van Raden Industries, Inc.
Post Office Box 6346
Portland, OR 97228

Dear Mr. Keenan:

Please pardon the delay in responding to your letter to Walter Myers of my staff in which you asked whether directly controlling different axles with an antilock braking system (ABS) on a 3-axle stinger-steered log trailer that your company manufactures would be permitted under the trailer ABS requirements. It is our opinion that your trailer is a pole trailer which is excluded from the ABS requirements.

You stated that your 3-axle log trailer consists of a collapsible drawbar, a tandem axle pony, ball-bearing turntable, log bunk, mainframe gooseneck, and last axle. You attached a drawing of the trailer which shows that the mainframe gooseneck on which is mounted the last axle is permanently attached to the trailer by the turntable. The first 2 of the 3 axles concerned, designated in your drawing as axles 5 and 6, are attached to the trailer while the last axle, designated in your drawing as axle 7, is permanently connected to axles 5 and 6 by means of the turntable. You presented a scenario in which axle 6 is directly controlled by ABS while axles 5 and 7 are indirectly controlled by ABS. In a second scenario axle 7 is directly controlled by ABS while axles 5 and 6 are indirectly controlled. Your specific question was whether either or both of these scenarios would comply with the ABS requirements.

Your description of your trailer and the drawings that you enclosed with your letter show that the trailer meets the definition of a "pole trailer," which is defined in 49 CFR 571.3 as:

[A] motor vehicle without motive power designed to be drawn by another motor vehicle and attached to the towing vehicle by means of a reach or pole, or by being boomed or otherwise secured to the towing vehicle, for transporting long or irregularly shaped loads such as poles, pipes, or structural members capable generally of sustaining themselves as beams between the supporting connections.

Your trailer appears to meet the above definition in the following respects:

a. The trailer is designed to be drawn by another motor vehicle, and even if the drawbar would not meet the definition of a reach, pole, or boom, it could be considered to fall within the "otherwise secured to the towing vehicle" definition;

b. The logs that the trailer transports are "long or irregularly shaped loads" and, in addition, would be generally capable of sustaining themselves as beams between supporting connections.

Paragraph S5.2.3.1(a) and (b) of Federal Motor Vehicle Safety Standard No. 121, Air brake systems, require that semitrailers and full trailers manufactured on or after March 1, 1998 be equipped with antilock brake systems (ABS). The definitions of semitrailers and full trailers both exclude pole trailers from the terms of those respective definitions. Thus, pole trailers are excluded from the requirement to be equipped with ABS. Since your trailer is excluded from compliance with Standard No. 121, you would be free to install either of the systems described in your scenarios. Of course, sound engineering judgment would be warranted to assure that the system installed does not contain a defect related to motor vehicle safety.

The towing vehicle depicted in your drawing appears to be a truck rather than a truck tractor since it has load-carrying capacity other than as a towing vehicle only. You should be aware, therefore, that the ABS equipment and road test requirements for tractors differ from those for straight trucks, especially in their stopping distance requirements.

I hope this information is helpful to you. Should you have any further questions or need additional information, feel free to contact Mr. Myers at this address or at (202) 366-2992, fax (202) 366-3820.

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:121
d.4/21/99