Oklahoma Liquefied Petroleum Gas Administration — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation 400 Seventh St., S.W. Washington, D.C. 20590 Research and OCT 20 2004 special Programs Administration Mr. W.A. Glass Ref. No.: 03-0284 Administrator Oklahoma Liquefied Petroleum Gas Administration SuiteB-45 2101 North Lincoln Boulevard Oklahoma City, OK 73105 Dear Mr. Glass: This is in response to your November 6, 2003 letter requesting clarification regarding bobtails and the applicability of the term "cargo tank motor vehicle" as specified in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). A "bobtail," as specified in the context of this letter, is a cargo tank that is not mounted to a trailer. Specifically, you ask if the definition for the term "cargo tank motor vehicle," as referenced in § 173.315(n), is only applicable to bobtails. Please accept my apology for our delay in responding to your letter. The answer is no. The term "cargo tank motor vehicle," applies to all configurations of cargo tank motor vehicles. See enclosure. Section 171.8 defines "cargo tank motor vehicle" as a motor vehicle with one or more cargo tanks permanently attached to or forming an integral part of the motor vehicle. A "motor vehicle" as a defined in § 171.8, includes a vehicle, machine, tractor, trailer, or semitrailer, or any combination thereof, propelled or drawn by mechanical power and used on highways to transport passengers or property. Therefore, a cargo tank that is attached to a motor vehicle chassis, including a trailer or semitrailer, is considered a "cargo tank motor vehicle." I hope this information is helpful. Please contact us if you require additional assistance. Sincerely,, Hitter. mithel Hattie L. Mitchell Chief, Regulatory Review and Reinvention Office of Hazardous Materials Standards Enclosure 171.8 030284 173.315 (n)#

Page 2Cargo Tank Motor Vehicles MC-331 High Pressure Tank (semitrailer) BOBTAIL TANK (no trailer) DOT 406/MC 306 Non Pressure Liquid Tank (trailer) 030284B#

Page 3Nov-06-03 12:13P LP GAS ADMIN 4055216037 P.02 Edmonson 5111.8 November 6, 2003. § 113.3151) Mr. Edward Mazzullo Cargo Tanks Definition. Director, Office of Hazardous Material Standard USDOT/RSPA (DHM-10) 03-0284 400 7" Street S.W. Washington, D.C. 20590-0001 Dear Mr. Mazzullo: I would like an opinion regarding 49 CFR 171.8, definition for "cargo tank motor vehicle". The definition for "cargo tank motor vehicle" in 171.8 would lead one to think it only applies to vehicles with permanently attached cargo tanks, or "bobtail type vehicles" The definition for "motor vehicle" in 171.8 includes bobtails and semi- trailers. The definition for "cargo tank" in 171.8 seems to describe both bobtails and semi-trailer transports. Question: Reference 173.315(n). If "cargo tank motor vehicle" only pertains to bobtails, then where are the requirements for tractor trailer or semi-trailer transports? Please answer by letter or Fax (405)-521-6037 Respectfully, ICe Slum W.A. Glass Administrator#