Design Certifying Engineer — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department Washington, D.C. 400 Seventh Streel, S.W. 20590 Research and Special Programs Administration OCT 2 7 2000 Mr. David Fellows Ref. No. 00-0277 Design Certifying Engineer 904 Hawks Hollow Delafield, Wisconsin 53018 Dear Mr. Fellows: This responds to your letter, dated September 20, 2000, concerning installation of a non-metallic packing gland in the bulkhead of a specification cargo tank under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You provided two news articles about cargo tanks manufactured with internal agitation systems that utilize this design feature. As you noted in your July 5, 2000 letter on this subject, the HMR do not specifically prohibit a design modification of the type described in the articles. However, if a non-metallic seal or packing gland is utilized, it must be as strong and heat resistant as the material used for construction of the cargo tank (see § 178.345-9(h)). It is not clear from the information you provided that the cargo tanks described conform to this requirement. The Federal Motor Carrier Safety Administration intends to investigate further with cargo tank manufacturers and operators to ascertain whether these cargo tanks conform to HMR specification requirements and, if not, to advise manufacturers and operators on options for achieving compliance with the HMR. I hope this information is helpful. If you have further questions, please do not hesitate to contact this office. Sincerely, omar A. All Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards 178,345 000277#

Page 2DAYAN CEMENTIO f Bulk Transport Design and Application Pneumatic Dry Bulk Trailers Petroleum Tank Trailers Equipment and Systems Sanitary Tank Trailers Chemical Tank Trailers 2178.345 Delafield, Wisconsin 53018 904 Hawks Hollow e-mail Davfellows@aol.com D.O.T. Registored D.C.E. Phone 262/646-5440 Cargo Tanks Fax 262/646-2527 00-0277 September 20, 2000 Mr. Thomas G. Allen Senior Transportation Regulations Specialist Office of Hazardous Materials Standards, RSPA. U.S. Department of Transportation 400 Seventh Street S.W. Washington DC. 20590-0001 Ref. No. 00-0190 Dear Mr. Allen, Thank you for your letter of August 9, 2000 regarding the appropriateness of installing a non-metalic packing gland in the bulkhead of a Specification cargo tank. In your memo you indicated that it was difficult to evaluate the merits of such a design without seeing a picture or design specifications. I am enclosing reprints of two articles on cargo tanks produced with this design feature. The articles are from Modern Bulk Transporter, and Trailer Body Builder, both published about 1995 or 1996. I have no information that these cargo tanks have been involved in a hazardous materials incident. It appears that enclosing the external part of the mechanism in a secondary enclosure would be feasible. My interest in this subject was brought about by questions I received from business associates and clients regarding the use of the through the shell rotating seal on Specification cargo tanks. Thank you for your response. Varied alar David Fellows Design Certifying Engineer CT-5132 Enc. Two Winter Address • 14 Majorca Dr. • Rancho Mirage, CA 92270 • Phone 760/202-0435 • Fax 760/321-0574#