Interpretation Response #16-0115
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
August 10, 2016
Mr. John Heater
Transportation Safety and Security Specialist
The Dow Chemical Company
100 Independence Mall West
Philadelphia, PA 19106
Ref. No. 16-0115
Dear Mr. Heater:
This responds to your June 29, 2016, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR parts 171-180) applicable to the use of stainless steel as a material of construction for DOT Specification 117 (DOT-117) tank cars. On May 8, 2015, the Pipeline and Hazardous Materials Safety Administration (PHMSA) published HM-251, a Final Rule titled “Hazardous Materials: Enhanced Tank Car Standards and Operation Controls for High-Hazard Flammable Trains” [80 FR 26643] which adopted prescriptive, performance, and retrofit standards for DOT-117 tank cars. Your questions are paraphrased and answered below:
Q1. You note that in accordance with DOT-117 prescriptive standards the only material of construction authorized is AAR TC-128 Grade B, normalized steel and ask if any alternate materials, such as stainless steel, may be used when building DOT-117 tank cars.
A1. The answer is yes. Section 179.202-1 requires that each DOT-117 tank car be built in accordance with the general requirements of § 179.200 and the prescriptive standards in
§§ 179.202-1 through 179.202-11 or the performance standards in § 179.202-12. The prescriptive standards for DOT-117 tank cars require the use of, at a minimum, 9/16 inch AAR TC-128, Grade B, normalized steel. While no other materials are prescribed, alternate designs will be considered in accordance with the performance specification standards of
§ 179.202-12. This may allow a DOT-117 tank car to be built with stainless steel. DOT-117 performance standards were intentionally incorporated into HM-251 to drive innovation and allow for variations in the DOT-117 tank car specifications.
Q2. You ask how to proceed in an obtaining an approval to build a stainless steel DOT-117 tank car.
A2. In order for a DOT-117 tank car to be built with stainless steel, it must meet the performance standards outlined in § 179.202-12 (see A1). Section 179.202-12(a) requires tank car design, testing, and modeling results be reviewed and approved by the Associate Administrator for Railroad Safety/Chief Safety Officer, Federal Railroad Administration (FRA), 1200 New Jersey Ave. S.E., Washington, DC 20590.
Q3. You ask for consideration in adopting stainless steel as a prescribed material of construction for DOT-117 tank cars and provide reasons for its incorporation.
A3. As mentioned in A1 above, the performance standards in § 179.202-12 have been designed to allow for variations in the DOT-117 tank car, as you suggest.
I trust this satisfies your inquiry. Please contact us if we can be of further assistance.
Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division
179.202-1, 179.202-12, 179.200, 179.202-1, 179.202-11
|§ 179.202-11||Individual specification requirements|