# Hazardous Materials: Improving the Safety of Railroad Tank Car Transportation of Hazardous Materials

- **operation:** document
- **citation:** 74 FR 1770
- **title:** Hazardous Materials: Improving the Safety of Railroad Tank Car Transportation of Hazardous Materials
- **source type:** rulemaking
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** historical
- **official:** true
- **published on:** 2009-01-13
- **effective on:** 2009-03-16
- **summary:** The Pipeline and Hazardous Materials Safety Administration (PHMSA), in coordination with the Federal Railroad Administration (FRA), is amending the Hazardous Materials Regulations to prescribe enhanced safety measures for rail transportation of poison inhalation hazard (PIH) materials, including interim design standards for railroad tank cars. Pending validation and implementation of the crashworthiness performance standard proposed in the NPRM issued under this docket on April 1, 2008, the rule mandates commodity-specific improvements in safety features and design standards for newly manufactured DOT specification tank cars. The rule also adopts a 50 mph speed restriction for loaded rail tank cars transporting PIH materials; an improved top fittings performance standard; an allowance to increase the gross weight of tank cars that meet the enhanced standards; and adoption of the industry standard for normalized steel in certain tank cars. The interim standards established in this rule will enhance the accident survivability of PIH tank cars when compared to existing regulations while providing tank car owners continued flexibility in car selection. Adoption of this interim standard will ensure the ongoing availability of tank cars while PHMSA and FRA complete research and testing on advanced tank car design to validate and implement a more stringent performance standard.
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- **source url:** https://www.federalregister.gov/documents/2009/01/13/E8-31056/hazardous-materials-improving-the-safety-of-railroad-tank-car-transportation-of-hazardous-materials
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Federal Register, Volume 74 Issue 8 (Tuesday, January 13, 2009) [Federal Register Volume 74, Number 8 (Tuesday, January 13, 2009)] [Rules and Regulations] [Pages 1770-1802] From the Federal Register Online via the Government Publishing Office [ www.gpo.gov ] [FR Doc No: E8-31056] [[Page 1769]] ----------------------------------------------------------------------- Part II Department of Transportation ----------------------------------------------------------------------- Pipeline and Hazardous Materials Safety Administration ----------------------------------------------------------------------- 49 CFR Parts 171, 172, et al. Hazardous Materials: Improving the Safety of Railroad Tank Car Transportation of Hazardous Materials; Final Rule Federal Register / Vol. 74, No. 8 / Tuesday, January 13, 2009 / Rules and Regulations [[Page 1770]] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts 171, 172, 173, 174 and 179 [Docket No. FRA-2006-25169] RIN 2130-AB69 Hazardous Materials: Improving the Safety of Railroad Tank Car Transportation of Hazardous Materials AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT). ACTION: Final rule. ----------------------------------------------------------------------- SUMMARY: The Pipeline and Hazardous Materials Safety Administration (PHMSA), in coordination with the Federal Railroad Administration (FRA), is amending the Hazardous Materials Regulations to prescribe enhanced safety measures for rail transportation of poison inhalation hazard (PIH) materials, including interim design standards for railroad tank cars. Pending validation and implementation of the crashworthiness performance standard proposed in the NPRM issued under this docket on April 1, 2008, the rule mandates commodity-specific improvements in safety features and design standards for newly manufactured DOT specification tank cars. The rule also adopts a 50 mph speed restriction for loaded rail tank cars transporting PIH materials; an improved top fittings performance standard; an allowance to increase the gross weight of tank cars that meet the enhanced standards; and adoption of the industry standard for normalized steel in certain tank cars. The interim standards established in this rule will enhance the accident survivability of PIH tank cars when compared to existing regulations while providing tank car owners continued flexibility in car selection. Adoption of this interim standard will ensure the ongoing availability of tank cars while PHMSA and FRA complete research and testing on advanced tank car design to validate and implement a more stringent performance standard. DATES: Effective Date: March 16, 2009. The incorporation by reference of the publication listed in the rule is approved by the Director of the Federal Register as of March 16, 2009. Incorporation by Reference Date: The incorporation by reference of the publications adopted in Sec. 171.7 of this final rule has been approved by the Director of the Federal Register as of March 16, 2009. FOR FURTHER INFORMATION CONTACT: William Schoonover, (202) 493-6229, Office of Safety Assurance and Compliance, Federal Railroad Administration; Lucinda Henriksen, (202) 493-1345, Office of Chief Counsel, Federal Railroad Administration; or Michael Stevens, (202) 366-8553, Office of Hazardous Materials Standards, Pipeline and Hazardous Materials Safety Administration. SUPPLEMENTARY INFORMATION: Abbreviations and Terms Used in This Document AAR--Association of American Railroads ASLRRA--American Short Line and Regional Railroad Association BNSF--BNSF Railway Company BLET--Brotherhood of Locomotive Engineers and Trainmen CPC--Casualty Prevention Circular CI--Chlorine Institute CP--Canadian Pacific CPR--Conditional Probability of Release CSXT--CSXT Transportation Department--U.S. Department of Transportation DOW--Dow Chemical Company DOT--U.S. Department of Transportation Federal Hazmat Law--Federal hazardous materials transportation law (49 U.S.C. 5101 et seq.) FRA--Federal Railroad Administration HMR--Hazardous Materials Regulations NGRTCP--Next Generation Rail Tank Car Project NPRM--Notice of Proposed Rulemaking NTSB--National Transportation Safety Board OMB--Office of Management and Budget PHMSA--Pipeline and Hazardous Materials Safety Administration PIH--Poison Inhalation Hazard R&D--Research and Development RSAC--Railroad Safety Advisory Committee RSI--Railway Supply Institute SAFETEA-LU--Safe, Accountable, Flexible, Efficient, Transportation Equity Act: A Legacy for Users, Public Law 109-59 SBA--Small Business Administration Tank Car Manual--Association of American Railroads Tank Car Committee Tank Car Manual TCC--Association of American Railroads Tank Car Committee TFI--The Fertilizer Institute TIH--Toxic Inhalation Hazard TSA--Department of Homeland Security, Transportation Security Administration Trinity--Trinity Industries, Inc. UTU--United Transportation Union Union Tank--Union Tank Car Company UP--Union Pacific Railroad Company Volpe--Volpe National Transportation Systems Center Table of Contents for Supplementary Information I. Background II. Statutory Authority, Congressional Mandate, and NTSB Recommendations III. The Proposed Rule IV. Discussion of Comments on the Proposed Rule V. Discussion of Comments on Petitions for Interim Tank Car Standards VI. Summary of Rule VII. Section-by-Section Analysis VIII. Regulatory Analyses and Notices A. Statutory/Legal Authority for This Rulemaking B. Executive Order 12866 and DOT Regulatory Policies and Procedures C. Executive Order 13132 D. Executive Order 13175 E. Regulatory Flexibility Act and Executive Order 13272 F. Paperwork Reduction Act G. Regulation Identifier Number (RIN) H. Unfunded Mandates Reform Act I. Environmental Assessment J. Privacy Act I. Background On April 1, 2008, PHMSA published a notice of proposed rulemaking (NPRM) proposing revisions to the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to improve the crashworthiness protection of railroad tank cars designed to transport materials that are poisonous, or toxic, by inhalation (referred to as PIH or TIH materials). 73 FR 17818. The NPRM proposed enhanced tank car performance standards for head and shell impacts; operational restrictions for trains hauling tank cars containing PIH materials; interim operational restrictions for trains hauling tank cars used to transport PIH materials, but not meeting the enhanced performance standards; and an allowance to increase the gross weight on rail of tank cars that meet the enhanced tank-head and shell puncture-resistance systems. The NPRM provided detailed background information on the need to enhance the crashworthiness protection of railroad tank cars, government and industry efforts to improve the safety of hazardous materials transportation via railroad tank car, and the Department's research efforts focused on tank car safety. As we explained in the NPRM, although rail transportation of hazardous materials is a safe method for moving large quantities of hazardous materials over long distances, rail tank cars used to contain these materials have not been designed to withstand the force of high-speed derailments and collisions. In the last several years, rail tank cars have been breached in numerous accidents, resulting in large releases of hazardous materials. Of particular concern, three of these accidents involved PIH materials: (1) The January 18, 2002, derailment of a Canadian Pacific (CP) train in Minot, North Dakota which resulted in a catastrophic release of anhydrous ammonia; (2) the June 28, 2004 collision [[Page 1771]] between trains operated by Union Pacific Railroad Company (UP) Burlington Northern and Santa Fe Railway Company (now known as BNSF Railway Company) in Macdona, Texas, involving a breach of a loaded tank car containing chlorine; and (3) the January 6, 2005 collision between two Norfolk Southern Railway Company (NS) trains in Graniteville, South Carolina, also involving the catastrophic rupture of a loaded chlorine tank car. As noted in the NPRM, although none of these accidents was caused by the hazardous materials tank cars, the failure of the tank cars involved led to fatalities, injuries, evacuations, and property and environmental damage. In response to these accidents, related NTSB recommendations, and the Congressional mandate for tank car safety improvements in the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users, Public Law 109-59 (SAFETEA-LU), PHMSA and FRA initiated a comprehensive review of design and operational factors that affect rail tank car safety. As noted in the NPRM, DOT's on-going and multi-faceted strategy to enhance the safety of rail tank cars and transportation of hazardous materials by rail tank cars utilizes a risk-based, system- wide approach that addresses: (1) Tank car design and manufacturing; (2) railroad operational issues such as human factors, track conditions and maintenance, wayside hazardous detectors, signals and train control systems; and (3) improved planning and training for emergency response. Subsequent to publication of the NPRM, DOT hosted a two-day technical symposium on tank car crashworthiness and held a series of public meetings to solicit feedback on the NPRM. Although participants at both the technical symposium and public meetings generally agreed with DOT's goal of improving the accident survivability of tank cars, commenters expressed practical concerns regarding DOT's specific proposals. Also subsequent to publication of the NPRM, the Association of American Railroads (AAR) renewed the effectiveness of its previously suspended interchange standard for tank cars transporting PIH materials (Casualty Prevention Circular 1187 or CPC-1187). AAR's CPC-1187 implements interchange standards for the shell, head, and top fittings of PIH tank cars. Specifically, AAR's CPC-1187 interchange standard contains tank car head and shell design standards and an alternate performance standard based on the metric AAR terms ``conditional probability of release.'' The head and shell requirements of CPC-1187 can be met by using DOT specification tank cars of higher tank classes than required by DOT standards; however, tank cars built to meet the CPC-1187 standard would not meet the standards DOT proposed in the NPRM. CPC-1187 also requires tank cars used to transport PIH materials be equipped with top fittings protection systems designed to withstand, without loss of lading, a rollover with a linear velocity of 9 mph and that the top fittings protection system to be attached to the tank by welding. In addition, in response to the NPRM, the overwhelming majority of industry commenters have expressed the view that the standards proposed in the NPRM are ``technology-forcing'' and that the tank car industry currently lacks the technological and engineering ability to manufacture tank cars meeting the proposed standards. According to commenters, the net effect of these ``competing'' standards in CPC-1187 and the NPRM has been that shippers and tank car purchasers (e.g., tank car lessors) cannot currently purchase PIH tank cars with any assurance that the cars will have a reasonable economic life.\1\ Accordingly, commenters indicate that shippers and tank car owners are being forced to forego the phasing out of aging tank cars that they would normally retire and replace with new cars, potentially resulting in a shortage of cars needed for the transportation of PIH materials in the short term. While commenters generally express support for the development of a performance standard related to tank car puncture resistance, they recommend that DOT provide an interim solution to ensure the availability of PIH tank cars in the time period before DOT's proposed performance standards are finalized and tank cars can be built to meet those standards. --------------------------------------------------------------------------- \1\ The NPRM proposed the complete phase-out within eight years of all PIH tank cars not meeting the proposed performance standards. As noted above, cars built to meet the requirements of CPC-1187 would not meet the standards proposed in the NPRM and because of weight restrictions, it is possible that cars built to meet CPC-1187 might not be retrofitable to meet any portion of the final performance standard promulgated in this rulemaking. --------------------------------------------------------------------------- In this connection, in a petition dated July 3, 2008 (Joint Petition), the American Chemistry Council (ACC), American Short Line and Regional Railroad Association (ASLRRA), the Association of American Railroads (AAR), Chlorine Institute (CI), and Railway Supply Institute requested that the Department authorize interim standards for tank cars transporting PIH materials. In a separate petition filed on July 7, 2008, The Fertilizer Institute (TFI) made a similar request.\2\ Each of these petitions is discussed in more detail below. --------------------------------------------------------------------------- \2\ PHMSA assigned petition numbers P-1525 and P-1524 to the Joint Petition and TFI petition, respectively. On July 23, 2008, PHMSA published a notice soliciting public comment on the petitions under docket number PHMSA-2008-0182. 73 FR 42765. --------------------------------------------------------------------------- Based on comments received in response to the NPRM and the two petitions for rulemaking, in this rule FRA and PHMSA are adopting interim standards for tank cars used to transport PIH materials. This rule is an interim response based on current engineering judgments within the affected market sector. DOT intends to continue working with the industry to complete research and testing on advanced tank car design. Accordingly, we anticipate additional regulatory proceedings as the results of continuing government and private sector research and development are validated and the resulting technology is successfully implemented by industry. DOT intends that the standards set forth in this rule shall apply in the meantime, pending the development and commercialization of more stringent performance standards. II. Statutory Authority, Congressional Mandate, and NTSB Recommendations Federal hazmat law authorizes the Secretary of DOT (Secretary) to ``prescribe regulations for the safe transportation, including security, of hazardous material in intrastate, interstate, and foreign commerce.'' The Secretary has delegated this authority to PHMSA. 49 CFR 1.53(b). The HMR, promulgated by PHMSA under the authority provided in Federal hazmat law, are designed to achieve three goals: (1) To ensure that hazardous materials are packaged and handled safely and securely during transportation; (2) to provide effective communication to transportation workers and emergency responders of the hazards of the materials being transported; and (3) to minimize the consequences of an incident should one occur. The hazardous material regulatory system is a risk management system that is prevention-oriented and focused on identifying a safety or security hazard and reducing the probability and quantity of a hazardous material release. Under the HMR, hazardous materials are categorized by analysis and experience into hazard classes and packing groups based upon the risks that they present during transportation. The HMR specify appropriate packaging and handling requirements for hazardous materials, and require a [[Page 1772]] shipper to communicate the material's hazards through the use of shipping papers, package marking and labeling, and vehicle placarding. The HMR also require shippers to provide emergency response information applicable to the specific hazard or hazards of the material being transported. Finally, the HMR mandate training requirements for persons who prepare hazardous materials for shipment or who transport hazardous materials in commerce. The HMR also include operational requirements applicable to each mode of transportation. The Secretary also has authority over all areas of railroad transportation safety (Federal railroad safety laws, 49 U.S.C. 20101 et seq.), and has delegated this authority to FRA. 49 CFR 1.49. Pursuant to its statutory authority, FRA promulgates and enforces a comprehensive regulatory program (49 CFR parts 200-244) to address railroad track; signal systems; railroad communications; rolling stock; rear-end marking devices; safety glazing; railroad accident/incident reporting; locational requirements for the dispatch of U.S. rail operations; safety integration plans governing railroad consolidations; merger and acquisitions of control; operating practices; passenger train emergency preparedness; alcohol and drug testing; locomotive engineer certification; and workplace safety. FRA inspects railroads and shippers for compliance with both FRA and PHMSA regulations. FRA also conducts research and development to enhance railroad safety. In addition, both PHMSA and FRA are working with the emergency response community to enhance its ability to respond quickly and effectively to rail transportation accidents involving hazardous materials. As noted above, on August 10, 2005, Congress passed SAFETEA-LU, which added section 20155 to the Federal hazmat law. 49 U.S.C. 20155. In part, section 20155 required FRA to (1) validate a predictive model quantifying the relevant dynamic forces acting on railroad tank cars under accident conditions, and (2) initiate a rulemaking to develop and implement appropriate design standards for pressurized tank cars. In response to the accident in Minot, North Dakota, on January 18, 2002, in which a train derailment resulted in the catastrophic release of anhydrous ammonia leading to one death and 11 serious injuries, the NTSB made four safety recommendations to FRA specific to the structural integrity of hazardous material tank cars. The NTSB recommended that FRA analyze the impact resistance of steels in the shells of pressure tank cars constructed before 1989 and establish a program to rank those cars according to their risk of catastrophic failure and implement measures to eliminate or mitigate this risk. The NTSB also recommended that FRA validate the predictive model being developed to quantify the maximum dynamic forces acting on railroad tank cars under accident conditions and develop and implement tank car design-specific fracture toughness standards for tank cars used for the transportation of materials designated as Class 2 hazardous materials under the HMR. In response to the accident in Graniteville, South Carolina, on January 6, 2005, in which a train collision resulted in the breach of a tank car containing chlorine and nine people died from inhalation of chlorine vapors, the NTSB recommended, in part, that FRA ``require railroads to implement operating measures such as * * * reducing speeds through populated areas to minimize impact forces from accidents and reduce the vulnerability of tank cars transporting'' certain highly-hazardous materials. Each of these NTSB recommendations is discussed in the NPRM.\3\ --------------------------------------------------------------------------- \3\ See 73 FR 17818, 17826-28. The NPRM indicated that NTSB classified FRA's responses to Safety Recommendations R-05-15 and R- 05-16 stemming from the Graniteville accident as ``Open-Response Received.'' Subsequently, in a letter dated June 7, 2007, however, NTSB classified these recommendations as ``Closed-Unacceptable Action'' and ``Open-Unacceptable Response.'' A copy of NTSB's June 7, 2007, letter is available in the docket. --------------------------------------------------------------------------- The Department considers this rule responsive to section 20155's mandate, as well as to the NTSB recommendations. As discussed in more detail in section IV below, however, we recognize that this rule does not directly implement each of the relevant NTSB recommendations. Instead, the interim standards we are adopting in this rule are only the first part of a longer-term strategy to enhance the safety of rail shipments of PIH materials. Improving the safety and security of hazardous materials transportation via railroad tank car is an on-going process. We plan to continue to develop and validate a performance standard to further improve the crashworthiness of PIH tank cars, with a view towards incorporating the improved performance standard into the HMR. Going forward, FRA's hazardous materials research and development program will continue to focus on reducing the rate and severity of hazardous materials releases by optimizing the manufacture, operation, inspection, and maintenance procedures for the hazardous materials tank car fleet. In addition, we plan to continue our holistic approach to rail safety, as discussed in detail in the NPRM, including railroad operating and maintenance practices; railroad routing practices; shipper commodity handling practices; and emergency response procedures. III. The Proposed Rule Generally, the NPRM proposed a two-pronged approach to enhancing the accident survivability of tank cars. First, the NPRM proposed to limit the operating conditions of tank cars transporting PIH materials. Second, the NPRM proposed enhanced tank-head and shell puncture resistance standards. The NPRM described FRA's research demonstrating that the speed at which a train is traveling has the greatest effect on the closing velocity between cars involved in a derailment or accident situation and that the secondary car-to-car impact speed in such situations is approximately one-half the initial train speed (the speed of the train at the time of the collision or derailment). Based on this research, the Department recognized that limiting the operating speed of tank cars transporting PIH materials is one potential method to impose a control on the forces experienced by railroad tank cars. Accordingly, we proposed two operational speed restrictions: (1) A maximum speed limit of 50 mph for all trains transporting railroad tank cars containing PIH materials; and (2) A maximum speed limit of 30 mph in non-signaled (i.e., dark) territory for all trains transporting railroad tank cars containing PIH materials, unless the material is transported in a tank car meeting the enhanced tank-head and shell puncture-resistance systems performance standards of this proposal. As an alternative to the maximum speed limit of 30 mph in dark territory, we proposed submission for FRA approval of a complete risk assessment and risk mitigation strategy establishing that operating conditions over the subject track provide at least an equivalent level of safety as that provided by signaled track. In conjunction with these speed restrictions, we also proposed improved tank-head and shell puncture-resistance standards. The enhanced standards proposed to require tank cars that transport PIH materials in the United States to be designed and manufactured with a shell puncture-resistance system capable of withstanding impact at 25 mph and with a tank-head puncture resistance system capable of [[Page 1773]] withstanding impact at 30 mph. To ensure timely replacement of the PIH tank car fleet, we proposed an eight-year implementation schedule, contemplating design, development, and manufacturing ramp-up in the first two years, replacement of 50% of the fleet within the next three years, and replacement of the remaining 50% of the fleet in the following three years. As part of this implementation plan, we proposed the expedited replacement of tank cars used for the transportation of PIH materials manufactured before 1989 with non-normalized steel head or shell construction.\4\ Recognizing that improvements in tank car performance have historically relied in large part on thicker and/or stronger steel, which brings with it a corresponding addition to the empty weight of the tank car, we also proposed an allowance to increase the gross weight on rail for tank cars designed to meet the proposed enhanced tank-head and shell puncture-resistance systems performance standards (up to 286,000 pounds). --------------------------------------------------------------------------- \4\ Non-normalized steel is steel that has not been subjected to a specific heat treatment procedure that improves the steel's ability to resist fracture. --------------------------------------------------------------------------- IV. Discussion of Comments on the Proposed Rule Subsequent to publication of the NPRM, DOT hosted a technical symposium on tank car crashworthiness and conducted four public meetings to solicit comment on the proposed rule. The intent of the technology symposium was to provide a forum for FRA and PHMSA to share with the tank car industry the agencies' collective knowledge and experience in the testing and design of rail tank cars significantly more crashworthy than conventional tank cars, as well as to provide parties involved in the manufacturing, repairing, and testing of tank cars an opportunity to openly discuss issues related to the manufacturing of such tank cars. We received approximately 50 written comments in response to the NPRM, including comments from members of the railroad and PIH shipping industry, trade organizations, local governments, tank car manufacturing and repair companies, members of Congress, as well as members of the general public. Several of these commenters also provided verbal comments at the public meetings held during the subsequent comment period. The following discussion provides an overview of the written and verbal comments DOT received in response to the NPRM and how DOT has chosen to address those comments in this rule. As previously noted, two petitions were filed requesting DOT to establish interim tank car standards; comments on these petitions are set forth in Section V. More detailed discussions of specific comments on the NPRM and the petitions for interim standards, as well as DOT's responses, can be found in the relevant Section-by-Section analysis portion of the preamble. Generally, commenters recognize the need to improve the crashworthiness of PIH tank cars and express support for DOT's efforts in the NPRM. For example, the NTSB supports the stated goals of the NPRM and states that many aspects of the proposal, when implemented, will significantly improve the safety of the transportation of PIH materials in railroad tank cars. The AAR applauds DOT's issuance of the NPRM as a ``truly innovative approach'' to tank car design and CI indicates that the organization ``fully supports the major step forward'' DOT took in issuing the proposed rule. Although commenters also generally support the development of a performance standard focused on tank car puncture resistance such as that proposed \5\ commenters also raise important practical concerns regarding DOT's specific proposals. The majority of commenters' concerns are focused on (1) the technical basis for and feasibility of achieving, in the short term, the proposed tank-head and shell puncture resistance performance standards; (2) the proposed eight-year implementation period, including the proposed accelerated replacement of cars constructed with non- normalized steel; (3) the proposed allowance to increase the gross weight on rail of PIH tank cars; (4) the proposed speed restrictions, particularly the interim 30 mph speed restriction in dark territory for tank cars not meeting the proposed enhanced performance standards, but used to transport PIH materials; (5) the lack of proposed enhancements to PIH tank car top fittings; (6) the need for an interim standard for tank cars used to transport PIH materials; and (7) the costs associated with implementing the proposed rule. --------------------------------------------------------------------------- \5\ Trinity Industries, Inc. (Trinity), a tank car builder, comments that issuance of the proposed puncture resistance performance standard is inconsistent with SAFETEA-LU's mandate to develop ``appropriate design standards'' for pressurized rail tank cars. Although we respectfully disagree with Trinity's comment, we note that the issue would not appear to be relevant to this rule in that we are adopting tank car design standards. --------------------------------------------------------------------------- A. Proposed Performance Standards The majority of commenters express the view that although the 25 and 30 mph shell and head-impact puncture resistance standards are laudable goals, such proposed standards are ``technology forcing'' and achieving such impact resistance utilizing existing technology and currently accepted tank car engineering practices is not possible in the short term. For example, Dow, a driving force behind the Next Generation Rail Tank Car Project (NGRTCP),\6\ suggests that although the 25 mph shell-impact puncture resistance system standard (which represents a six-fold performance improvement over existing chlorine tank cars) may be obtainable based upon the design concepts and technologies developed by the NGRTCP, the proposed 30 mph head impact standard (which represents a ten to twelve-fold improvement over existing chlorine cars) is outside the range of solutions contemplated by the Project. Noting that no existing tank car designs under review as part of the NGRTCP would meet the proposed head and shell-impact standards, tank car builders estimate that it will take up to ten years until a design proven to meet the proposed performance standards (both 25 mph shell-impact and 30 mph head-impact puncture resistance standards) could be ready for full-scale implementation. Other commenters indicate that it may take approximately three years until a design proven to meet the proposed 25 mph puncture resistance standard will be ready for full-scale implementation. These commenters' concerns regarding the time required until the tank car industry can meet the proposed performance standards are discussed in more detail below with other comments related to the proposed implementation period. --------------------------------------------------------------------------- \6\ The NGRTCP is discussed in detail in the preamble to the NPRM. See 73 FR 17833-34. --------------------------------------------------------------------------- Some commenters, noting the synergy between the proposed 50 mph speed limit for PIH tank cars and the 25 mph shell impact puncture resistance performance standard, question the efficacy of the proposed 30 mph head-impact standard. As explained in the NPRM and by FRA staff at the May 28, 2008, public meeting, the 30 mph head impact standard was intended to protect against impacts when a tank car is involved in the primary collision (i.e., impacts other than the secondary car-to- car impacts upon which the proposed 50 mph speed limit was based). FRA believes that in such instances, it is desirable to have additional head-impact protection strategies available to help reduce the risk of loss of lading and that the available space in front of the tank-head will accommodate sufficient energy absorbing material [[Page 1774]] between the head shield or jacket and the inner commodity tank. See 73 FR 17849. NTSB acknowledges that establishing tank car puncture resistance at 25 mph would be an improvement that would enhance tank car safety. NTSB suggests, however, that such standard does not represent a standard for ensuring safety in 50-mph collisions because the general premise upon which the standard is based (i.e., the finding by the Volpe National Transportation Systems Center (Volpe) that the secondary car-to-car impact speed is one-half that of the initial train speed) is not applicable to all derailment conditions. Specifically, noting the two- dimensional, linear model utilized in Volpe's research, NTSB recommends the development and validation of more technically rigorous models that include consideration of the many three-dimensional, highly nonlinear dynamic responses that occur in derailment situations. Noting that its Safety Recommendation R-04-06 contemplates the consideration of different types of critical-loading conditions observed in derailments, NTSB suggests that although improving the puncture-resistance of tank cars is an important safety enhancement, by itself, it does not fully respond to Safety Recommendation R-04-06. Accordingly, NTSB suggests that additional modeling and validation is necessary to understand the full range of dynamic responses that occur in derailments. We appreciate NTSB's comments in this regard and as we pursue continued research and development on advanced car design, we will continue to further refine our quantification of the dynamic forces acting on railroad tank cars in accident conditions. CI notes that the proposed 30 mph head-impact standard represents an ``exponential increase in severity over the existing head protection requirement'' and questions whether the proposed standard goes beyond what is necessary to protect the integrity of the tank in real world accident scenarios. Noting its own efforts to address tank car puncture resistance, CI explains that its research demonstrates that a significant improvement (2x) in puncture resistance is possible if tank cars are constructed of steels with higher fracture toughness than AAR TC 128B steel (the steel typically used in tank car construction). Consistent with its Safety Recommendation R-04-07, NTSB similarly recommends that a standard for the fracture toughness of tank car construction materials be included in any final DOT tank car standard. NTSB suggests that the inherent material variability identified through FRA's research is common to the class of steel utilized and has been used in other applications to define fracture-based criteria. Although DOT believes that material properties play an important role in the performance of a tank car subjected to fatigue type loading, FRA's research has clearly demonstrated that for the impact conditions typical of accidents that result in a release, a holistic approach is required to prevent a breach of the commodity tank. As noted in the NPRM, however, DOT will continue to examine the dynamic fracture toughness of steels used in the construction of pressure tank cars in hazardous materials service and we will incorporate any workable tank car design-specific fracture toughness standards into the final performance standards. Other commenters note that the Volpe concept work (described in detail at the technology symposium) \7\ does not establish the feasibility of the proposed performance standards. Several commenters express the view that because the Volpe concept car differs significantly from traditional rail car designs and manufacturing methods, questions regarding the sill design, movement of the tank during yard impacts, how the car will be constructed, and other technical details need to be fully evaluated before the car can be manufactured and put into service. Commenters note that the proposed performance standards are based on impacts of 25 (shell) and 30 mph (head) from a 286,000 pound mass concentrated through a 6'' x 6'' impactor. Citing a recent head impact test by the NGRTCP, one tank car builder, American Railcar Industries (ARI), concludes that even meeting the 25 mph shell-impact puncture resistance standard requires a larger impactor, or less impacting weight. Another manufacturer suggests that it may be possible to achieve the 25 mph standard with the 6'' x 6'' impactor due to the deformations that are likely to occur, but the 30 mph standard probably would not be achievable. --------------------------------------------------------------------------- \7\ Copies of technical presentations from the symposium, as well as a summary of the symposium is available in the docket. --------------------------------------------------------------------------- Noting that current research has focused on development of a chlorine car (the Volpe ``concept car'') to meet the proposed performance standards, commenters express the view that other PIH materials (e.g., anhydrous ammonia, ethylene oxide, methyl mercaptan, anhydrous hydrogen fluoride) have significantly different physical and chemical properties that must be accommodated in tank car designs. For example, product density affects how much product can be loaded into a car. Arkema, a shipper of methyl mercaptan, a raw material used in the production of animal feeds for the poultry and swine industry, notes that chlorine weighs approximately 12 pounds per gallon, while methyl mercaptan weighs only about 7.8 pounds per gallon. Because chlorine is a rather dense material as compared to other PIH materials, the typical chlorine car has smaller tank dimensions than tank cars designed to transport other PIH materials. As Dow notes, these smaller tank dimensions have allowed the NGRTCP to design a chlorine car with greater thickness and greater standoff distances (i.e., the distance between the tank and the tank's outer protection) than may be possible for tank cars designed to carry other PIH commodities. Commenters also suggest that the differing physicochemical properties and severity of hazards presented by various PIH materials need to be considered when designing tank cars to handle particular PIH materials. DGAC notes that many PIH materials are highly flammable and will ignite prior to the formation of a toxic cloud. As an example, BASF notes that ethylene oxide has flammability ranges between 3% and 100% in air and therefore, that an ethylene oxide release would result in a fire before there was an opportunity to affect the general population from a toxicity hazard. BASF further notes that there is a significant difference in the danger posed by a Zone B PIH material (e.g., chlorine) versus a Zone D PIH material (e.g., ethylene oxide). Commenters further state that the disparate physicochemical properties of the various PIH materials shipped via railroad tank car have historically led to very specific car designs for certain materials. For example, DuPont notes that oleum and sulfur trioxide have relatively high freezing points. Accordingly, rail cars intended for the transportation of oleum and sulfur trioxide must be equipped with sufficient insulation capable of maintaining the temperature of the chemicals above their respective freezing points. Similarly, tank cars used to transport chlorosulfonic acid are constructed of stainless steel tanks to prevent discoloring of the acid. According to DuPont, there is no feasible alternative to stainless steel and the properties of the stainless steel inner tanks relative to the puncture resistance requirements of the proposed performance standards would have to be considered. Similarly, shippers of [[Page 1775]] anhydrous hydrogen fluoride and hydrofluoric acid note that the corrosive properties of these chemicals have led to non-jacketed tank car designs for these particular commodities and that the non-jacketed cars allow for visual detection of any corrosive product on the outside of the commodity tank before it can compromise the integrity of the tank. Noting the Volpe concept car presented at the technology symposium and the NGRTCP car design rely on a ``sandwich'' (i.e., layered design with a jacket encompassing supporting foam or other energy absorbing material surrounding and isolating the commodity tank from the structural forces of the moving train), these commenters suggest that such a design concept would introduce new maintenance and inspection challenges that could lead to a detriment in safety in that the inner tank could not be inspected as readily as is currently possible. Although DOT recogn
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