Interpretation ID: 18398.wkm

Mr. W. Randolph Schlegel
MEGA Corporation
700 Osuna Road, NE
Albuquerque, NM 87113-1037

Dear Mr. Schlegel:

This responds to your letter faxed to this office on September 17, 1998, to Walter Myers of my staff in which you asked whether the stand tank that your company produces would be excluded from the antilock brake system (ABS) requirements of Federal Motor Vehicle Safety Standard (Standard) No. 121, Air brake systems. The answer is yes.

You enclosed with your letter pictures and a drawing of the water tank in question. It can be described as a large, portable, tubular-shaped tank trailer that is raised on its platform when in use and lowered for transport. You stated that the tank is used by contractors on off-highway construction sites and stays at the site for the duration of the job, which could be a few days or some years. You stated that you feel that you "are in compliance with the 49 CFR Chapter V Section 571.121(f) as our stand tank has an unloaded vehicle weight which is 100 percent of its GVWR." We assume that you are referring to paragraph S5.3(f) of Standard No. 121 (49 CFR 571.121). If so, you are correct.

Paragraph S5.3(f) of Standard No. 121 excludes from the requirements of the standard "any trailer that has an unloaded vehicle weight which is not less than 95 percent of its GVWR [gross vehicle weight rating], . . ." Accordingly, since your standing water tank is filled only when being used at its work site and is completely emptied before being transported to any other location, it would be excluded from the requirements of Standard No. 121 by virtue of paragraph S5.3(f).

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

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:121
d.12/21/98