Interpretation Response #16-0042
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Truck Trailer Manufacturers Association
Individual Name: John Freiler
Location State: VA Country: US
View the Interpretation Document
Response text:
June 15, 2017
John Freiler
Truck Trailer Manufacturers Association
7001 Heritage Village Plaza
Suite 220
Gainesville, VA 20155
Reference No. 16-0042
Dear Mr. Freiler:
This letter is in response to your March 10, 2016, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the manufacture of Department of Transportation (DOT) specification cargo tanks. Specifically, you ask PHMSA to reconsider whether accident damage protection devices specified in § 178.345-8 (applicable to DOT 406, DOT 407, and DOT 412 cargo tanks) are considered structural support members as opposed to appurtenances as stated in our guidance issued July 17, 2015, under Reference No. 15-0049.
Our previously issued guidance on this issue remains valid. An accident damage protection device meets the definition of an appurtenance as defined in §§ 178.320 and 178.345-1. If required, accident damage protection devices for DOT 406, DOT 407, and DOT 412 cargo tanks must be attached to the cargo tank in accordance with the requirements of § 178.345-8(a)(3). If accident damage protection is applied directly to the cargo tank wall, the accident damage protection device must have no lading retention or containment function and provide no structural support to the cargo tank. Accident-induced stresses resulting from the appropriate accident damage protection device requirements in combination with the stresses from the cargo tank operating at the maximum allowable working pressure (MAWP) may not result in a cargo tank wall stress greater than the ultimate strength of the material of construction using a safety factor of 1.3.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division