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5 Tasks Broadly Relevant to Railroad Safety This chapter examines the completeness and quality of 3 of the 15 tasks in the Pipeline and Hazardous Materials Safety AdministrationâFederal Railroad Administration (PHMSAâFRA) Task Force initiative that are foundational to railroad safety assurance, whether freight or passenger movements. The three tasks are Train Energy Dynamics Simulator, Electronically Controlled Pneumatic Brakes, and Automated Track Inspection Program. TRAIN ENERGY DYNAMICS SIMULATOR The objective of this task is to simulate liquefied natural gas (LNG) train operations under various conditions for a single originâdestination pair from Wyalusing, Pennsylvania, to Gibbstown, New Jersey, through Philadelphia, Pennsylvania, using the Train Energy and Dynamics Simulator (TEDS) software. TEDS simulates train behavior based on models that rely on train operations, head-end or distributed power, braking, the type of railcar that makes up the train, and track and environmental conditions. TEDS was developed and validated using real- world train operations for FRA from 2013 to 2016. As used in this task, 100-car unit train operations were simulated over two rail routes designated for LNG transport in DOT-113 tank cars under various conditions. The TEDS simulation of the LNG unit train for this originâdestination pair includes three head-end locomotives followed by one buffer car with an approximate train length of 8,500 feet (1.6 miles). The simulation results produced train speed, coupler forces, and lateral and vertical force ratio (L/V ratio) 95 predictions within recognized industry safety limits. 96 There is significant overlap between the two routes considered in the simulation. Simulation studies are essential tasks in the analysis and prediction of new or different train operations. They can assess dynamic performance and engineering risks; produce physics- based results; and quantify the dynamic parameters for a wide range of geometric, environmental, and operating conditions. Such data can be used within either a deterministic or statistical framework for identifying, quantifying, and assessing the risk and effectiveness of mitigation measures. The TEDS model informs and is informed by other tasks. The model uses data from the Automated Track Inspection Program, and the simulation results can inform the tasks on Punctures and Derailment Simulation Modeling, Safety and Security Route Risk Assessment, and Train Operational Controls. 95 The lateral and vertical force ratio, or L/V ratio, is a relationship in railway engineering between the lateral and vertical forces imparted to the rail and wheel that is used to understand the risk of a derailment caused by excessive lateral force pushing up the wheel over the rail. 96 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, âFRAâPHMSA LNG by Rail Task Force Interim Report,â p. 18. PREPUBLICATION COPYâUncorrected Proofs 45
Observations About Completeness and Quality The Task Force showed that an appropriate simulation tool was used to analyze a proposed unit train with a consist of 100 DOT-113 tank cars, and that the results exhibit coupler forces and L/V ratio predictions within recognized industry safety limits for the particular originâdestination pair. Also, the simulated train handling achieves acceptable speed and braking. However, there were a number of gaps in the model regarding train make-up, motive power, and the buffer car. The committee views the decision to simulate only LNG movements by unit train as a shortcoming because manifest (i.e., mixed freight) operations are commonplace in freight railroad operations. The model also omitted distributed power (DP), a common form of motive power wherein locomotives may pull from the front, push from the rear, or assist midway within a train. The predictions of in-train forces, such as coupler forces, can vary significantly depending on the location and quantities of the locomotives. Indeed, DP is one of the two options for compliance with an operational requirement under the final rulemaking in 2020. In addition, the specifics of the buffer car were not clearly documented. In some cases, the length and weight of a buffer car can contribute to derailments from excessive wheel climb risk. For example, because a typical DOT-113 for LNG is about 80 feet, a buffer car of less than 45 feet in length or weighing less than 90,000 pounds may be unsuitable. In summary, this task would be improved by providing justification for the selected train make-up parameters (e.g., placement and number of locomotives, number and variety of freight cars) and considering alternative route parameters while explaining their omission from the model. Additional details such as these would strengthen the report because it is not clear how the simulation of a single train on two specific routes âwill inform future activities to prepare for the future transportation of LNG by railâ in a general sense. 97 ELECTRONICALLY CONTROLLED PNEUMATIC BRAKES The Task Force evaluated the costs and benefits of requiring electronically controlled pneumatic (ECP) brakes for LNG by rail transportation. LNG movements by rail will require a new DOT- 113 tank car fleet (i.e., the newly specified DOT-113C120W9), providing a potential opportunity to include alternate braking systems in the design if cost-effective and beneficial to safety. Task Force members completed all planned analyses, but will coordinate with the Bureau of Transportation Statistics to track the demand for the new DOT-113 tank cars, as an increase in demand could change the assumptions, and thus the findings, of the analysis. The Task Force reviewed the existing ECP braking analysis for HHFTs to assess whether ECP braking systems are cost-justified and feasible for LNG transportation by rail. Assumptions in the analysis included: â¢ DOT-113C120W9 car production would consume the maximum build capacity currently available; â¢ Equipment costs would be zero on new builds although there would be training costs on the use of such braking systems; 97 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, p. 20. PREPUBLICATION COPYâUncorrected Proofs 46
â¢ Braking effectiveness was based on a Transportation Research Board study; 98 and â¢ All existing and produced cars would be used full-time for LNG transportation. 99 Only these assumptions were presented; no actual analysis was available. Based on the assumptions, the Task Force determined that nearly 50 years of maximum production of ECP- equipped tank cars would be needed to reach the point where the business and safety benefits exceeded the costs of adding and using ECP brakes. Detailed information, whether qualitative or quantitative, regarding the assumptions and calculations was not provided. Observations About Completeness and Quality The implementation of ECP brakes could be a risk-mitigating factor included in a comprehensive QRA of LNG by rail. Any resulting change in risk would then inform the final costâbenefit analysis of ECP brakes. However, because of the paucity of information available to the committee for its review, there are insufficient grounds to support or assess the conclusions of the ECP braking analysis or to inform the consideration of ECP brakes as a mitigation measure in a comprehensive QRA. Without details on how the costs were derived and the basis of assuming the effectiveness of the ECP brakes, the quality of the Task Forceâs recent evaluation cannot be determined. Specific gaps in the available information include justification of the actual effectiveness of ECP systems; consideration of the need for locomotives and buffer car(s) to also be ECP brake-equipped in a unit train for ECP braking systems to function; and recognition that LNG tank cars in a manifest train would effectively have no brakes if only the DOT-113 tank car designs are modified, as ECP brakes do not function with the conventional air brakes found on the other cars in a manifest train. AUTOMATED TRACK INSPECTION PROGRAM This task focuses on assessing the track quality, maintenance, and safety of the two routes designated in the 2019 special permit for transportation of LNG by DOT-113 tank car between Wyalusing, Pennsylvania, and Gibbstown, New Jersey. The track data along those routes informing this task were obtained in March 2020 through the Automated Track Inspection Program (ATIP), 100 a decades-long FRA track inspection effort implemented network-wide to ensure track safety. The earliest iteration of the technologies used in this inspection program dates back to the late 1960s and is related to the initial efforts to use track geometry data for maintenance-of-way planning in 1971. 101 98 National Academies of Sciences, Engineering, and Medicine, A Review of the Department of Transportationâs Plan for Analyzing and Testing Electronically Controlled Pneumatic Brakes Letter Report (Phase 2), 2017, https://doi.org/10.17226/24903. 99 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, âFRAâPHMSA LNG by Rail Task Force Interim Report,â July 2020, pp. 22â23. 100 Federal Railroad Administration, âHistory of Automated Track Inspection Program (ATIP),â November 17, 2019, https://railroads.dot.gov/track/automated-track-inspection-program-atip/history-atip. 101 Federal Railroad Administration Office of Research, Development and Technology, âAcquisition and Use of Track Geometry Data in Maintenance-of-Way Planning,â pp. 11, 17, n.d., PREPUBLICATION COPYâUncorrected Proofs 47
An FRA-developed fleet of eight vehicles are central to ATIP activities and are deployed to survey (i.e., inspect) track infrastructure for compliance with federal standards, not merely those related to hazardous material transportation. The inspection vehicles range in capabilities, from crewed and uncrewed operations to LiDAR (light detection and ranging) and track component imaging systems, and generally are instrumented at least for: â¢ Differential Global Positioning System for enhanced accuracy in measuring location; â¢ Track Geometry Measurement System for track gauge, cross-level, alignment (i.e., straightness of the rail), and rail surface (i.e., the relative elevation of points on parallel rails); â¢ Ride Quality Measurement System; and â¢ Rail Impact Detection System to detect damage at rail joints. Collected data are directly related to operational safety and drive inspection and maintenance activities. In case of exceptions (i.e., track issues), FRA performs an initial verification and issues a report to the maintaining railroad for further action that will ensure compliance with federal track safety standards, 102 possible upgrades to the infrastructure, or both. In 2019, FRA inspected 125,000 miles of track under ATIP. 103 FRA compared the data from March 2020 with test data collected over the previous 10 years on the same routes to identify trends in track safety. The Task Force reported that the route through Enola, Pennsylvania, in the Harrisburg area (i.e., Route 1) 104 has fewer track exceptions based on current and past measurements. Indeed, the 2020 inspection found no significant decreases in track condition on this route, an improvement over the six found in the past. 105 FRA plans to continue the ATIP-based surveys nationwide and will also reinspect the designated routes before the first LNG shipment to ensure compliance. The amount of data generated by ATIP surveys is massive. To support ATIP data management, FRA staff explained that the agency created a technology group in 2020 to examine its data infrastructure and analytics capabilities. There will also be consideration of cybersecurity issues. The rail carriers conduct automated track inspections using comparable technologies as a part of their normal inspection process on a voluntary basis. FRA staff noted that industry data and its own could be integrated, and that they regularly share information with the railroads. The data from track surveys could be used to validate the analysis in simulation tasks, although no documentation was available about ATIP survey data used elsewhere in the Task Forceâs work. https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/16595/1717%20Acquisition%20and%20Use%20of%20Track %20Geometry%20Data%20in%20Maintenance-of-Way%20Planning.pdf. 102 Federal Railroad Administration, âTrack Safety Standards,â 49 CFR Â§ 213, 2019, https://www.govinfo.gov/content/pkg/CFR-2019-title49-vol4/xml/CFR-2019-title49-vol4-part213.xml. 103 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, âFRAâPHMSA LNG by Rail Task Force Interim Report,â p. 25. 104 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, âTrain Energy Dynamics Simulator Task Resource,â August 13, 2020, p. 23, http://onlinepubs.trb.org/onlinepubs/dvb/LNGrail/Train_Engy_Dyn_Sim.pdf. 105 Pipeline and Hazardous Materials Safety Administration and Federal Railroad Administration, âFRAâPHMSA LNG by Rail Task Force Interim Report,â pp. 25â26. PREPUBLICATION COPYâUncorrected Proofs 48
Observations About Completeness and Quality ATIP is a well-established and mature program that uses track geometry measurement vehicles equipped with state-of-the-art technology for data acquisition. This task successfully demonstrates the effectiveness of the ATIP in identifying track issues in the designated routes for LNG transportation to ensure track quality, maintenance, and safety. Also, the committee was encouraged by a formal FRA effort to bolster its digital infrastructure and analytics for large datasets such as ATIP-generated data. Although this task appears to lack interaction with others, the survey data can be of great value for simulation studies in other tasks, such as TEDS, to develop more realistic models of track conditions and simulation scenarios. The usefulness of this type of data cannot be overstated. Rail carriers already voluntarily implement track geometry car systems as a quality assurance measure in fulfilment of required track inspection and maintenance. This task could be improved by incorporating industry-collected track geometry data for this route to enhance FRAâs own. Based on the value of the track condition survey in this task, the consistent implementation of ATIP surveys and data analysis on future routes designated for LNG transportation by rail is important to support mitigating risk related to track component defects. PREPUBLICATION COPYâUncorrected Proofs 49