Heil Trailer International — Hazardous Materials Safety Interpretation

Page 1S. Departmer Transportatic 400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and Hazardous Materials Safety Administration AUG 1 2005 MI• Joe Calonge Ref. No.: 05-0122 Chief Engineer Heil Trailer International 1125 Congress Parkway, N.E. P.O. Box 160 Athens, TN 37371-0160 Dear Mr. Calonge: This is in clarification of the requirements response to your May 10, 2005 letter requesting for accident damage protection for DOT 406 cargo tank motor vehicles under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) . Specifically you ask if you may construct recesses within the shell of the cargo tank for service equipment (such as valves, fittings, and manholes) . The answer is yes. In your letter and attached drawings you describe and depict recesses at the top of the cargo tank, shell of the tank. which prevent the, service equipment from protruding beyond the are not subject to accident damage protection (see § 178.345-8). However, the recesses are part of the cargo tank and must be constructed in accordance with all applicable requirements in Part 178, Subpart J. I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, Itathe R Mitchel Hattie L. Mitchell Office of Hazardous Materials Standards Chief, Regulatory Review and Reinvention 178-345-8 050122#

Page 2Pollack HEIL TRAILER INTERNATIONAL $178,345-8 HEIL P. O. BOX 160 • ATHENS, TENNESSEE 37371-0160 1125 CONGRESS PARKWAY, N. E. Accident Samage Protectio TELEPHONE (423) 745-5830 FAX (423) 745-5863 A E DOVER COMPANY 05-0122 Ms. Susan Gorsky May 10t* 2005 Regulations Officer US Department of Transportation Pipelines & Hazardous Materials Administration Office of Hazardous Materials Standards 400 7' Street SW Washington, DC. 20590 Re: Accident Damage Protection Madam: Our company Heil Trailer International manufactures and certifies DOT- 406 specification cargo tank motor vehicles. in the top of cargo tank see (49 CFR 178.345-8(a)(1) and (178.345-8(c)(1) & (2) by We are considering providing accident damage protection to the devices usually located ecessing the openings, opening closures, valves, fittings, pressure relief devices, vapo ecovery stop valves and lading retaining fittings, in a well of sufficient depth that it lie below the arc formed by the upper shell of the cargo tank.. The structural integrity of such well will be as robust as the surrounding cargo tark shell. The purpose of this letter is to request an interpretation of the damage protection concept outlined above. Your input on this matter will be most appreciated Truly Yours oe Calong Chief Engineer jcalonge@heiltrailer.com#