American Industrial Transport, Inc. — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 March 28, 2024 Roger Dalske Vice President Engineering and Fleet Operations American Industrial Transport, Inc. 100 Clark Street St. Charles, MO 63301 Reference No. 23-0102 Dear Mr. Dalske: This letter is in response to your November 28, 2023, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to thermal protection systems on rail tank cars. You ask whether thermal protection systems included among the Department’s list of thermal protection systems that comply with the requirements of Part 179, Appendix B—and no longer require test verification per § 179.18(c) —can be combined. Specifically, you ask whether a different thermal protection system on the list may be used to repair a thermal protection system on the list that has already been installed on a tank car if the list does not specifically identify the two systems in use together. It is your understanding that it would be permissible to use one listed thermal protection system to repair another listed thermal protection system provided the tank car still meets the required performance standards set forth in the HMR, and that further test verification of the combined system would be unnecessary because separately both systems no longer require test verification. Based on the information in your letter and the included plans for repair of the thermal protection system, it is the opinion of this Office that your understanding is incorrect. The thermal protection systems that comply with Part 179, Appendix B and no longer require test verification per § 179.18(c), provide readily available options to be used wholly. Combining pieces of two or more systems from the thermal protection systems list will require test verification in accordance with the requirements of § 179.18(a)-(b), as the systems on the list were not tested in combination. I hope this information helpful. Please contact us if we can be of further assistance. Sincerely, Dirk Der Kinderen Chief, Standards Development Branch Standards and Rulemaking Division#

Page 2Roundtree Jones, Jessie Jane CTR (PHMSA) 23-0102 CONFIDENTIAL From: Dodd, Alice (PHMSA) Sent: To: Wednesday, November 29, 2023 2:00 PM Jones, Jessie Jane CTR (PHMSA) Subject: Attachments: Fwd: requesting interpretation of acceptable repair of thermal protection systems Public Version_AITX Interpretation Request - Thermal Protection System (11.28.23).pat; Confidential Version_AITX Interpretation Request - Thermal Protection System (11.28.23) pdf Jessie, Here you go thanks Get Outlook for ios From: Patrick, Eamonn (PHMSA) <eamonn.patrick@dot.gov> Sent: Wednesday, November 29, 2023 11:14:49 AM To: Dodd, Alice (PHMSA) <Alice.Dodd@dot.gov> Cc: DerKinderen, Dirk (PHMSA) <Dirk.DerKinderen@dot.gov>; Foster, Glenn (PHMSA) < Glenn.Foster@dot.gov>; Majors, Leonard (PHMSA) <leonard.majors@dot.gov> Subject: FW: requesting interpretation of acceptable repair of thermal protection systems Alice, Please see attached for a LOI request. Please check this in and assign to a specialist, and be sure to note that AITX is requesting confidential treatment. You can also let the assigned specialist know that Leonard and I have a lot of background on this request and we're happy to meet and discuss. -Eamonn From: Dalske, Roger <RDalske@aitx.com> Sent: Tuesday, November 28, 2023 3:47 PM To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov> Cc: Patrick, Eamonn (PHMSA) <eamonn.patrick@dot.gov>; O'Brien, Kenneth < KOBrien@aitx.com>; Dalske, Roger <RDalske@aitx.com> Subject: requesting interpretation of acceptable repair of thermal protection systems AITX is requesting interpretation of acceptable repair of thermal protection systems previously discussed at the October AAR Tank Car Meetings. Attached please find a public and confidential version of AITX's request for an interpretation from PHMSA. As indicated in its letter, AITX requests confidential treatment of the three procedures included as attachments to the confidential version of the letter pursuant to 49 C.F.R. § 105.30 because these documents constitute confidential business information relating to AITX's business operations, practices, and procedures, which are the type of business information exempt from the Freedom of Information Act, as set forth in 5 U.S.C. § 552(b)(4).#

Page 3Roger Dalske /X Vice President Engineering and Fleet Operations (636) 940-6185 | AITX.COM AITX 100 Clark Street | St. Charles, MO | 63301 E-mail: RDalske@aitx.com 2#

Page 4November 28, 2023 VIA ELECTRONIC MAIL ONLY INFOCNTR (PHMSA) INFOCNTR@dot.gov Standards and Rulemaking Division Pipeline and Hazardous Materials Safety Administration Attn: PHH 10, U.S. Department of Transportation, East Building 1200 New Jersey Avenue, SE. Washington, DC 20590 0001 Subject: Request for Interpretation of 49 C.F.R. § 179.18. To Whom It May Concern: The federal rules require that certain tank cars be equipped with a thermal protection system that meets the criteria specified in 49 C.F.R. § 179.18. The Hazardous Materials Regulations do not rth a thermal protection perfor- mance standard that each system must meet. Id. § 179.18(a). Compliance with the performance standard must be verified by analyzing the fire effects on the entire surface of the tank car using the analysis methodology set forth in § 179.18(b) and Appendix B to Part 179. PHMSA main- tains a list of thermal protection systems that comply with the requirements in Appendix B of 49 - sign specifications for the thermal protection system in order to incentivize and allow for innova- tion. 42 Fed. Reg. 46306, 46309 (Sept. 15, 1977) (Final Rule - Shippers; Specification for Pres- sure Tank Car Tanks). AITX intends to repair one system on the Approved Systems List with another system also on the Approved Systems List. Although the Approved Systems List does not specifically identify these two systems in use together as a combined system, both systems are identified on the Ap- proved Systems List and therefore no longer require test verification. Specifically, AITX owns and maintains tank cars that are equipped with a thermal protection system that includes insulation and an 11-gauge metal jacket that meets the requirements of procedure, AITX personnel use a thermal inspection camera to detect voids in the original ther- mal protection system of a tank car. AITX intends to repair such voids by applying a coating to the affected area such that the coating will overlap the identified voids to ensure all areas are ad- equately protected. The coating itself is an approved thermal protection system that is identified -lag coatings). Accordingly, AITX intends to use the two approved attached a copy of its infrared inspection procedure and its repair procedures that contemplate application of a coating (i.e., a second thermal protection system) to address voids in the original#

Page 5thermal protection system. AITX claims each of these procedures as confidential proprietary information pursuant to 49 C.F.R. § 105.30 and requests confidential treatment of these three pro-cedures.1 While § 179.18 does not expressly address this scenario, AITX understands it is permissible to use one approved thermal protection system to repair another approved thermal protection sys- tem provided the tank car still meets the performance standard set forth in § 179.18(a). Moreo- ver, AITX understands that further test verification of the combined system is unnecessary be- cause both individual thermal protection systems are identified on the Approved System List and no longer require test verification. Based on engineering principles, when making this repair AITX expects the following conditions will be maintained: 1. The pool fire and torch fire survival times will remain unchanged or potentially be im- proved by the new combined thermal protection system because each individual thermal protection system has already been verified to meet the § 179.18(a) thermal protection system performance standard. 2. The insulating characteristics of the original thermal protection system will be maintained or potentially exceeded using the combined system. The AAR MSPR Appendix A pres- sure relief device requirements will continue to be met because there will be no change to the pressure relief device. In addition, the combined thermal protection system is better insulated than the original thermal protection system. 3. The puncture resistance of the car will be maintained because the thickness of the head shields, tank and jacket will remain the same. In addition, AITX will undertake the following activities: 1. The original thermal protection system will be stabilized and evaluated to ensure it will continue to meet its intended function and design level of safety and reliability for the in- spection and test interval assigned to the safety system. 2. The combined thermal protection system will be evaluated to ensure it will meet its function and design level of safety and reliability for the inspection and test interval assigned to the combined safety system. 3. The changes to the thermal protection system are recorded on the AAR Certificate of -2) or through the Tank Car Integrated Data base (TCID), with reference to an approved COC, in accordance with AAR MSRP M-1002 requirements. 4. The tank car, as repaired with the combined thermal protection system, will continue to meet the federal DOT package specification requirements and applicable AAR rules. 1 AITX requests confidential treatment of these three procedures pursuant to 49 C.F.R. § 105.30 because these docu- which are the type of business information exempt from the Freedom of Information Act, as set forth in 5 U.S.C. § 552(b)(4). American Industrial Transport, Inc. 100 Clark Street St. Charles, MO 63301#

Page 6In summary, AITX is requesting that PHMSA confirm its understanding that AITX is permitted to use one approved thermal protection system to repair another approved thermal protection sys- tem that has an 11-gauge jacket. AITX will evaluate tank cars with a combined system to ensure that the combined system reliably meets its functional requirements for the inspection and test interval assigned to the safety system. Please feel free to contact me if you have any questions or require additional information regarding our request. Roger Dalske Vice President Engineering and Fleet Operations (636) 940-6185 | AITX.COM 100 Clark Street | St. Charles, MO | 63301 E-mail: RDalske@aitx.com CC: Eamonn Patrick eamonn.patrick@dot.gov KOBrien@aitx.com American Industrial Transport, Inc. 100 Clark Street St. Charles, MO 63301#

Page 7November 28, 2023 VIA ELECTRONIC MAIL ONLY INFOCNTR (PHMSA) INFOCNTR@dot.gov Standards and Rulemaking Division Pipeline and Hazardous Materials Safety Administration Attn: PHH 10, U.S. Department of Transportation, East Building 1200 New Jersey Avenue, SE. Washington, DC 20590 0001 Subject: Request for Interpretation of 49 C.F.R. § 179.18. To Whom It May Concern: The federal rules require that certain tank cars be equipped with a thermal protection system that meets the criteria specified in 49 C.F.R. § 179.18. The Hazardous Materials Regulations do not rth a thermal protection perfor- mance standard that each system must meet. Id. § 179.18(a). Compliance with the performance standard must be verified by analyzing the fire effects on the entire surface of the tank car using the analysis methodology set forth in § 179.18(b) and Appendix B to Part 179. PHMSA main- tains a list of thermal protection systems that comply with the requirements in Appendix B of 49 - sign specifications for the thermal protection system in order to incentivize and allow for innova- tion. 42 Fed. Reg. 46306, 46309 (Sept. 15, 1977) (Final Rule - Shippers; Specification for Pres- sure Tank Car Tanks). AITX intends to repair one system on the Approved Systems List with another system also on the Approved Systems List. Although the Approved Systems List does not specifically identify these two systems in use together as a combined system, both systems are identified on the Ap- proved Systems List and therefore no longer require test verification. Specifically, AITX owns and maintains tank cars that are equipped with a thermal protection system that includes insulation and an 11-gauge metal jacket that meets the requirements of procedure, AITX personnel use a thermal inspection camera to detect voids in the original ther- mal protection system of a tank car. AITX intends to repair such voids by applying a coating to the affected area such that the coating will overlap the identified voids to ensure all areas are ad- equately protected. The coating itself is an approved thermal protection system that is identified -lag coatings). Accordingly, AITX intends to use the two approved attached a copy of its infrared inspection procedure and its repair procedures that contemplate application of a coating (i.e., a second thermal protection system) to address voids in the original#

Page 8thermal protection system. AITX claims each of these procedures as confidential proprietary information pursuant to 49 C.F.R. § 105.30 and requests confidential treatment of these three pro-cedures.1 While § 179.18 does not expressly address this scenario, AITX understands it is permissible to use one approved thermal protection system to repair another approved thermal protection sys- tem provided the tank car still meets the performance standard set forth in § 179.18(a). Moreo- ver, AITX understands that further test verification of the combined system is unnecessary be- cause both individual thermal protection systems are identified on the Approved System List and no longer require test verification. Based on engineering principles, when making this repair AITX expects the following conditions will be maintained: 1. The pool fire and torch fire survival times will remain unchanged or potentially be im- proved by the new combined thermal protection system because each individual thermal protection system has already been verified to meet the § 179.18(a) thermal protection system performance standard. 2. The insulating characteristics of the original thermal protection system will be maintained or potentially exceeded using the combined system. The AAR MSPR Appendix A pres- sure relief device requirements will continue to be met because there will be no change to the pressure relief device. In addition, the combined thermal protection system is better insulated than the original thermal protection system. 3. The puncture resistance of the car will be maintained because the thickness of the head shields, tank and jacket will remain the same. In addition, AITX will undertake the following activities: 1. The original thermal protection system will be stabilized and evaluated to ensure it will continue to meet its intended function and design level of safety and reliability for the in- spection and test interval assigned to the safety system. 2. The combined thermal protection system will be evaluated to ensure it will meet its function and design level of safety and reliability for the inspection and test interval assigned to the combined safety system. 3. The changes to the thermal protection system are recorded on the AAR Certificate of -2) or through the Tank Car Integrated Data base (TCID), with reference to an approved COC, in accordance with AAR MSRP M-1002 requirements. 4. The tank car, as repaired with the combined thermal protection system, will continue to meet the federal DOT package specification requirements and applicable AAR rules. 1 AITX requests confidential treatment of these three procedures pursuant to 49 C.F.R. § 105.30 because these docu- which are the type of business information exempt from the Freedom of Information Act, as set forth in 5 U.S.C. § 552(b)(4). American Industrial Transport, Inc. 100 Clark Street St. Charles, MO 63301#

Page 9In summary, AITX is requesting that PHMSA confirm its understanding that AITX is permitted to use one approved thermal protection system to repair another approved thermal protection sys- tem that has an 11-gauge jacket. AITX will evaluate tank cars with a combined system to ensure that the combined system reliably meets its functional requirements for the inspection and test interval assigned to the safety system. Please feel free to contact me if you have any questions or require additional information regarding our request. Roger Dalske Vice President Engineering and Fleet Operations (636) 940-6185 | AITX.COM 100 Clark Street | St. Charles, MO | 63301 E-mail: RDalske@aitx.com CC: Eamonn Patrick eamonn.patrick@dot.gov KOBrien@aitx.com American Industrial Transport, Inc. 100 Clark Street St. Charles, MO 63301#