Rolling stock, particularly of freight railroads, is currently maintained using regular preventative and corrective maintenance schedules. This maintenance approach recommends sets of inspections and maintenance procedures based on the average expected wear and tear across their inventory. In practice, however, this approach to scheduling preventative maintenance is not always effective. When scheduled too soon, it results in a loss of operating revenue, whereas when it is scheduled too late, equipment failure could lead to costly and disastrous derailments. Instead, proactive maintenance scheduling based on Big Data Analytics (BDA) could be utilized to replace traditional scheduling, resulting in optimized maintenance cycles for higher train safety, availability, and reliability. BDA could also be used to discover patterns and relationships that lead to train failures, identify manufacturer reliability concerns, and help validate the effectiveness of operational improvements. In this work, we introduce a train inventory simulation platform that enables the modelling of different train components such as wheels, brakes, axles, and bearings. The simulator accounts for the wear and tear in each component and generates a comprehensive data set suitable for BDA that can be used to evaluate the effectiveness of different BDA approaches in discerning patterns and extracting knowledge from the data. It provides the basis for showing that BDA algorithms such as Random Forest [9] and Linear Regression can be utilized to create models for proactive train maintenance scheduling. We also show the capability of BDA to detect hidden patterns and to predict failure of train components with high accuracy.

Rail transportation industry has drawn a growing interest on the use of Radio Access Technology for critical and non-critical services to improve safety/reliability, performance, and passenger experience. During the past two decades the theory and practice of the MIMO communications has solidified to the point where MIMO is now the main infrastructure for several legacy and emerging radio access standards. In this paper, the impact of subway tunnels’ curvatures on the MIMO channel capacity is explored. A heuristic approach is proposed which provides an efficient and low complexity solution for the MIMO channel capacity in curved subway tunnels for both the C-MIMO and the D-MIMO paradigms. The suggested approach is quite versatile and can be swiftly expanded to the case of multi-segment inhomogeneous tunnels.

The reliability of finite element (FE) based deterministic structural analysis of railroad trackbed has improved significantly due to ever increasing computational powers. However, the application of probabilistic methods to incorporate the material and geometric variabilities in these FE analyses is still profoundly underworked. In this study, the influence of variability in granular layers’ modulus and thicknesses values on the railroad subgrade performance have been investigated by applying probabilistic method and using a 3-dimensional FE based numerical trackbed model previously developed and validated by the authors’ research group. The influence of these factors is accounted for by changing their coefficients of variance (COV) while keeping their means constant. Preliminary results revealed that the variation in subgrade modulus is the most influential factor for subgrade performance, both in terms of progressive shear failure and excessive plastic deformations, followed by ballast modulus. Variations in depths, for the range studied, remained passive to the subgrade performance. The findings of this work is of particular significance in evaluating the subgrade performance while including the material and geometric variations, which may be caused by construction imperfections, weather changes, and/or rail operations.

This paper presents the development and demonstration of an efficient reliability-based tool for the reinforced earth retaining wall design in heavy haul railway. Here, two major internal failure modes, rupture and pullout, are the focus in the demonstration. The First-Order Reliability Method (FORM) is adopted to estimate the probability of failure for each failure mode, and is implemented in a spreadsheet. The reliability analysis is conducted with the consideration of the effect of uncertainty in the reinforcement length, horizontal and vertical spacing between steel strips, tensile strength of steel strips as well as the material property of the backfills. Using this design tool, a few candidate designs can be easily obtained by meeting the acceptable probability of failure and the final design is determined based on cost. The results obtained using FORM are also verified by comparing with those from Monte Carlo simulation. This design tool is shown to be simple to use in the retaining wall design of the railway engineering.

Operational efficiency is one of the key performance indicators for all railroad systems. Infrastructure inspection and maintenance engineers are tasked with the responsibility of ensuring the reliability, availability, maintainability and safety of the railroad network. However, as rolling stock traffic density increases throughout the network, inspection and maintenance opportunities become less readily available. Inspection and maintenance activities normally take place at night, when there is little or no train movement to avoid disruption of normal railroad network operation. In addition, conventional inspection methodologies fail to deliver the efficiency required for the optimization of maintenance decisions, particularly with respect to track renewals, due to their defect detection sensitivity and level of resolution limitations. The fact that critical structural components such as rails and crossings (frogs) are randomly loaded increases the degree of uncertainty when trying to estimate their remaining service lifetime. Maintenance decisions are predominantly based on the feedback received from inspection engineers, coupled with empirical knowledge that has been gained over the years. The use of structural degradation models is too risky due to the uncertainty arising from the variable dynamic loads sustained by the rail track. The use of structural health monitoring techniques offers significant advantages over conventional approaches. First of all, it is non-intrusive and does not interrupt normal rail traffic operations. Secondly, defects can be detected and evaluated in real-time whilst their evolution can be monitored continuously, enabling maintenance to be scheduled in advance and at times where the need for rail network availability at the section concerned is at its lowest. This paper analyzes the potential risks and benefits of a gradual shift from traditional inspection approaches to advanced structural health monitoring techniques.

This paper provides an update to the 2015 paper titled “A New Energy Storage Substation for the Portland to Milwaukie Light Rail (PMLR) Extension” [4] presented at the 2015 JRC in San Jose. The energy storage substation (ESS) with super-capacitor technology manufactured by Siemens was installed in place of a utility-connected substation at the Tacoma substation location to capture the energy generated by braking light rail vehicles and store it in the ESS energy savings mode and feed it back to the traction power supply during vehicle acceleration. In voltage stabilization mode, the ESS will enable the rail system to maintain voltage system stability by ensuring the system voltage to remain within the required voltage ranges and prevent system disruptions due to low system voltage conditions. In the Fall 2015, the Tacoma ESS went into service as part of the PMLR Orange Line light rail extension. This paper presents the design concepts for the unit, briefly discusses installation and testing, and focuses on the optimization process, operating experience, energy savings and reliability. TriMet operates a fleet of 145 light rail vehicles on its 60 mile network. Approximately 75% of the energy regenerated during braking is captured and re-used, saving an estimated $1.8 M annually in energy cost. The Tacoma ESS capacity is approximately 2.5 kWh. The unit normally operates in energy savings mode, maximizing recovery and re-use of braking energy while the secondary voltage stabilization mode is available to maintain system operation during outage conditions. After more than two years of revenue service operation, detailed operating data is presented and analyzed, including reliability information and actual energy and cost savings.

Cameras are substantial elements to provide security to passengers in public spaces, e.g. in urban subway environments. Automated image processing algorithms are used more and more often to analyze the cameras’ video streams. However, misaligned cameras may produce serious problems by either generating false alarms or even being blind due to a shifted field of view. This paper presents two simple, real-time, and straight-forward software methods to detect camera movement and also allow for an adjustable tolerance, i.e. small changes are acceptable. The first approach shifts a reference edge (from a master image) along a convenient path; the second method uses distance measuring to detect a critical camera movement. Both methods are tested on real-world video from a subway environment. Since the algorithms are proposed for application in a railway environment with typically high requirements on operational robustness and reliability, special emphasis is put on constraints and limitations of the presented algorithms.

Competition is the driving force of any economic system, as it creates a challenging environment for service suppliers to provide affordable and reliable services to customers. Rail systems are an important element of the logistic chain, as they provide a unique service category (generally transporting large volumes at low unit costs) to shippers that otherwise would not be serviced by other modes — the so called captive shippers. In this scenario, competition is essential to guarantee the required service levels (availability and reliability), followed by competitive rates, which ultimately may influence shippers’ business competitiveness, both regionally and globally. Brazil and some North American countries (Canada, Mexico and United States), have a common feature, i.e. continental territories allied with the economic exploitation of bulky activities (industrial, mineral and agricultural), and, hence, depend strongly on heavy haul rail systems. These countries have been performing a continuous effort on improving competition practices into their rail systems, which are translated into important, and sometimes controversial, regulatory measures. These initiatives require a tenuous equilibrium, as they are supposed to provide the required competitive service at affordable rates for shippers, as well as a sustainable (financial and operational) environment to rail carriers, to guarantee the required return on long term investments and avoid compromising medium and long term rail network efficiency. This challenging task for rail market stakeholders (rail carriers, shippers and regulators) is far from a consensus. Rail companies claim that, as a capital intensive sector, governmental regulatory intervention into the rail system may inhibit their ability to invest the required funds to provide and expand rail capacity, as well as the maintenance of the required safety levels. Shippers, on the other hand, state that rail systems operate within a strong market concentration (originally formatted or due to subsequent merges and acquisitions) that give some rail carriers a disproportionate market power, that resembles a monopoly, which ultimately leaves a significant contingent of the so called captive shippers with just one freight rail carrier option, sometimes subjected to excessive rates, and, in some special instances (into offer restricted rail markets, for example), are responsible for the unavailability of rail services into the required volumes. In this context, there is currently a controversial debate regarding the effectiveness of competitive regulatory remedies into freight rail systems. This debate includes both market oriented rail systems (Canadian and U.S.), as well as rail contractual granted ones (Brazilian and Mexican). In the formers, the systems are mostly owned and operated by the private sector, and inter and intra modal options may theoretically provide the required competition level, while in the latter, rail systems have been broken into separate pieces and granted to the private sector under a concession arrangement, followed by an exclusive right to serve their territories, with trackage rights provisions, to be exerted by third parties, under previously defined circumstances and subjected to contractual agreements among rail operators. In both systems, competitive regulatory actions may be desirable and effective, as far as they may address the technical-operational-economic boundary conditions of each particular rail system. This work is supposed to present, into a review format, sourced from an extensive research into available international technical literature, and gathered as a unique document, an overview of the Brazilian and North American freight rail competition scenario, followed by a technical and unbiased effectiveness’ assessment of current (existing) and proposed competitive regulatory freight rail initiatives into Brazil, Canada, Mexico and United States, highlighting their strengths and eventually their weaknesses.

The railroad industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). TADS™ uses wayside microphones to detect and alert the conductor of high risk defects. Many defective bearings may never be detected by TADS™ due to the fact that a high risk defect is considered a spall which spans more than 90% of a bearing’s raceway, and there are less than 20 systems in operation throughout the United States and Canada. Much like the TADS™, the HBD is a device that sits on the side of the rail tracks and uses a non-contact infrared sensor to determine the temperature of the train bearings as they roll over the detector. The accuracy and reliability of the temperature readings from this wayside detection system have been concluded to be inconsistent when comparing several laboratory and field studies. The measured temperatures can be significantly different from the actual operating temperature of the bearings due to several factors such as the class of railroad bearing and its position on the axle relative to the position of the wayside detector. Over the last two decades, a number of severely defective bearings were not identified by several wayside detectors, some of which led to costly catastrophic derailments. In response, certain railroads have attempted to optimize the use of the temperature data acquired by the HBDs. However, this latter action has led to a significant increase in the number of non-verified bearings removed from service. In fact, about 40% of the bearings removed from service in the period from 2001 to 2007 were found to have no discernible defects. The removal of non-verified (defect-free) bearings has resulted in costly delays and inefficiencies. Driven by the need for more dependable and efficient condition monitoring systems, the University Transportation Center for Railway Safety (UTCRS) research team at the University of Texas Rio Grande Valley (UTRGV) has been developing an advanced onboard condition monitoring system that can accurately and reliably detect the onset of bearing failure. The developed system currently utilizes temperature and vibration signatures to monitor the true condition of a bearing. This system has been validated through rigorous laboratory testing at UTRGV and field testing at the Transportation Technology Center, Inc. (TTCI) in Pueblo, CO. The work presented here provides concrete evidence that the use of vibration signatures of a bearing is a more effective method to assess the bearing condition than monitoring temperature alone. The prototype bearing condition monitoring system is capable of identifying a defective bearing with a defect size of less than 6.45 cm 2 (1 in 2 ) using the vibration signature, whereas, the temperature profile of that same bearing will indicate a healthy bearing that is operating normally.

The increasing movement of people and products caused by modern economic dynamics has burdened transportation systems. Both industrialized and developing countries have faced transportation problems in urbanized regions and in their major intercity corridors. Regional and highway congestion have become a chronic problem, causing longer travel times, economic inefficiencies, deterioration of the environment and quality of life. Congestion problems are also occurring at airports and air corridors, with similar negative effects. In the medium distance travel market (from 160 up to 800 km), too far to drive and too short to fly, High Speed Rail (HSR) technology has emerged as a modern transportation system, as it is the most efficient means for transporting large passenger volumes with high speed, reliability, safety, passenger comfort and environmental performance. HSR system’s feasibility will depend on its capacity to generate social benefits (i.e. increased mobility rates, reduced congestion, capacity increase and reduced environmental costs), to be balanced with the high construction, maintenance and operational costs. So, it is essential to select HSR corridors with strong passenger demands to maximize these benefits. The first HSR line was Japan’s Shinkansen service, a dedicated HSR system, between Tokyo and Osaka, launched in 1964, which is currently the most heavily loaded HSR corridor in the world. France took the next step, launching the Train à Grande Vitesse (TGV), in 1981, with a dedicated line with shared-use segments in urban areas, running between Paris and Lyon. Germany joined the venture in the early 1990 with the Inter City Express – ICE, with a coordinated program of improvements in existent rail infrastructure and Spain, in 1992, with the Alta Velocidad Espanola – AVE, with dedicated greenfield lines. Since then, these systems have continuously expanded their network. Currently, many countries are evaluating the construction of new HSR lines, with European Commission deeming the expansion of the Trans European Network as a priority. United Kingdom, for example, has just awarded construction contracts for building the so called HS2, an HSRexpanded line linking London to the northern territory. China, with its dynamic economic development, has launched its HSR network in 2007 and has sped up working on its expansion, and currently holds the highest HSR network. United States, which currently operates high speed trainsets into an operationally restricted corridor (the so called Northeast Corridor (NEC), linking Washington, New York and Boston), has also embarked into the high speed rail world with the launch of Californian HSR Project, currently under construction, aimed to link Los Angeles to San Francisco mega regions, the ongoing studies for Texas HSR project, to connect Dallas to Houston, into a wholly privately funding model, as well as studies for a medium to long term NEC upgrade for HSR. Australia and Brazil are also seeking to design and launch their first HSR service, into a time consuming process, in which a deep discussion about social feasibility and affordability is under way. This work is supposed to present an overview of HSR technology worldwide, with an assessment of the main technical, operational and economical features of Asian and European HSR systems, followed by a snapshot of the general guidelines applied to some planned HSR projects, highlighting their demand attraction potential, estimated costs, as well as their projected economic and environmental benefits.

Prevention of railroad bearing failures, which may lead to catastrophic derailments, is a central safety concern. Early detection of railway component defects, specifically bearing spalls, will improve overall system reliability by allowing proactive maintenance cycles rather than costly reactive replacement of failing components. A bearing health monitoring system will provide timely detection of flaws. However, absent a well verified model for defect propagation, detection can only be used to trigger an immediate component replacement. The development of such a model requires that the spall growth process be mapped out by accumulating associated signals generated by various size spalls. The addition of this information to an integrated health monitoring system will minimize operation disruption and maintain maximum accident prevention standards enabling timely and economical replacements of failing components. An earlier study done by the authors focused on bearing outer ring (cup) raceway defects. The developed model predicts that any cup raceway surface defect (i.e. spall) once reaching a critical size (spall area) will grow according to a linear correlation with mileage. The work presented here investigates spall growth within the inner rings (cones) of railroad bearings as a function of mileage. The data for this study were acquired from defective bearings that were run under various load and speed conditions utilizing specialized railroad bearing dynamic test rigs owned by the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV). The experimental process is based on a testing cycle that allows continuous growth of railroad bearing defects until one of two conditions are met; either the defect is allowed to grow to a size that does not jeopardize the safe operation of the test rig, or the change in area of the spall is less than 10% of its previous size prior to the start of testing. The initial spall size is randomly distributed as it depends on the originating defect depth, size, and location on the rolling raceway. Periodic removal and disassembly of the railroad bearings was carried out for inspection and defect size measurement along with detailed documentation. Spalls were measured using optical techniques coupled with digital image analysis, as well as, with a manual coordinate measuring instrument with the resulting field of points manipulated in MatLab™. Castings were made of spalls using low-melting, zero-shrinkage bismuth-based alloys, so that a permanent record of the spall geometry and its growth history can be retained. The main result of this study is a preliminary model for spall growth, which can be coupled with bearing condition monitoring tools that will allow economical and effective scheduling of proactive maintenance cycles that aim to mitigate derailments, and reduce unnecessary train stoppages and associated costly delays on busy railways.

The bond between wire and concrete is crucial for transferring the stresses between the two materials in a prestressed concrete member. Furthermore, bond can be affected by such variables as thickness of concrete cover, type of pre-stressing (typically indented) wire used, compressive (release) strength of the concrete, and concrete mix. This work presents current progress toward the development of a testing procedure to get a clear picture of how all these parameters can ruin the bond and result in splitting. The objective is to develop a qualification test procedure to proof-test new or existing combinations of pre-stressing wire and concrete mix to ensure a reliable result. This is particularly crucial in the concrete railroad crosstie industry, where incompatible conditions can result in cracking and even tie failure. The goal is to develop the capability to readily identify compatible wire/concrete designs “in-plant” before the ties are manufactured, thereby eliminating the likelihood that defectively manufactured ties will lead to in-track tie failures due to splitting. The tests presented here were conducted on pre-tensioned concrete prisms cast in metal frames. Three beams (prismatic members) with different cross sections were cast simultaneously in series. Four pre-stressing wires were symmetrically embedded into each concrete prism, resulting in a common wire spacing of 2.0 inches. The prisms were 59.5in long with square cross sections. The first prism was 3.5 × 3.5in with cover 0.75in, the second was 3.25 × 3.25in with cover 0.625in and the third prism in series was 3.0 × 3.0 in with cover 0.50in. All pre-stressing wires used in these initial tests were of 5.32 mm diameter and were of the same wire type (indent pattern) denoted by “WE”, which had a spiral-shaped geometry. This is one of several wire types that are the subject of the current splitting propensity investigation. Others wire types include variations of the classical chevron shape, and the extreme case of smooth wire with no indentions. The wires were initially tensioned to 7000 pounds (31.14 KN) and then gradually de-tensioned after reaching the desired compressive strength. The different compressive (release strength) strength levels tested included 3500 psi (24.13 MPa), 4500psi (31.03 MPa), 6000 psi (41.37 MPa) and 12000psi (82.74MPa). A consistent concrete mix with water-cement ratio 0.38 was used for all castings. Geometrical and mechanical properties of test prisms were representative of actual prestressed concrete crossties used in the railroad industry. Each prism provided a sample of eight different and approximately independent splitting tests of concrete cover (four wire cover tests on each end) for a given release strength. After de-tensioning, all cracks that appeared on the prisms were marked, and photographs of all prism end surfaces were taken to identify the cracking field. During the test procedure longitudinal surface strain profiles, along with live-end and dead-end transfer lengths, were also measured using an automated Laser-Speckle Imaging (LSI) system developed by the authors. Both quantitative and qualitative assessment of cracking behavior is presented as a function of cover and release strength. In addition to the identification of whether cracking took place at each wire end location, measurements of crack length and crack area are also presented for the given WE wire type. The influence of concrete cover and release strength are clearly indicated from these initial tests. The influence of indented wire type (indent geometry) will also be discussed in this paper, along with a presentation of some preliminary test results. This work represents a successful first step in the development of a qualification test for validating a given combination of wire type, concrete cover, and release strength to improve the reliability of concrete railroad crosstie manufacturing.

American Railroads are planning to complete implementing their Positive Train Control (PTC) systems by 2020. Safety objectives of PTC are to avoid inter-train collisions, train derailments and ensuring railroad worker safety. Under published specifications of I-ETMS (the PTC system developed by Class I freight railroads), the on-board PTC controller communicates with two networks; namely, the Signaling network and the Wayside Interface Unit network to gather navigational information such as the positions of other trains, the status of critical infrastructure (such as switches) and any hazardous conditions that may affect the train path. By design, PTC systems are predicated on having a reliable radio network operating in reserved radio spectrum, although the PTC system itself is designed to be a real-time fail safe distributed control systems. Secure Intelligent Radio for Trains (SIRT) is an intelligent radio that is customized to train operations with the aim of improving the reliability and security of the radio communication network. SIRT has two tiers. The upper tier has the Master Cognitive Engine (MCE) which communicates with other SIRT nodes to obtain signaling and wayside device information. To do so, the MCE communicates with cognitive engines at the lower tier of SIRT; namely the Cryptographic Cognitive Engine (CCE) (that provide cryptographic security and threat detection) and the Spectrum Management Cognitive Engine (SCE) (that uses spectrum monitoring, frequency hopping and adaptive modulation to ensure the reliability of the radio communication medium). We presented the architecture and the prototype development of the CCE in [1]. This paper presents the design of the MCE and the SCE. We are currently developing a prototype of the SCE and the MCE and testing the performance of our cognitive radio system under varying radio noise conditions. Our experiments show that SIRT dynamically switches modulation schemes in response to radio noise and switches channels in response to channel jamming.

Prevention of bearing failures which may lead to catastrophic derailment is a major safety concern for the railroad industry. Advances in bearing condition monitoring hold the promise of early detection of bearing defects, which will improve system reliability by permitting early replacement of failing components. However, to minimize disruption to operations while providing the maximum level of accident prevention that early detection affords, it will be necessary to understand the defect growth process and try to quantify the growth speed to permit economical, non-disruptive replacement of failing components rather than relying on immediate removal upon detection. The study presented here investigates the correlation between the rate of surface defect (i.e. spall) growth per mile of full-load operation and the size of the defects. The data used for this study was acquired from defective bearings that were run under various load and speed conditions utilizing specialized railroad bearing dynamic test rigs operated by the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV). Periodic removal and disassembly of the railroad bearings was carried out for inspection and defect size measurement and documentation. Castings were made of spalls using low-melting, zero shrinkage Bismuth-based alloys so that a permanent record of the full spall geometry could be retained. Spalls were measured using optical techniques coupled with digital image analysis and also with a manual coordinate measuring instrument with the resulting field of points manipulated in MatLab™ and Solidworks™. The spall growth rate in area per mile of full-load operation was determined and, when plotted versus spall area, clear trends emerge. Initial spall size is randomly distributed as it depends on originating defect depth, size, and location on the rolling raceway. The growth of surface spalls is characterized by two growth regimes with an initial slower growth rate which then accelerates when spalls reach a critical size. Scatter is significant but upper and lower bounds for spall growth rates are proposed and the critical dimension for transition to rapid spall growth is estimated. The main result of this study is a preliminary model for spall growth which can be coupled to bearing condition monitoring tools to permit economical scheduling of bearing replacement after the initial detection of spalls.

This paper presents the result of an evaluation program for the condition of the SEPTA Broad Street subway car shells and their capability to perform during an extended period of revenue service. SEPTA currently is evaluating various system upgrades to address equipment obsolescence and reliability, and wanted to verify that the current car shells are expected to be serviceable during this extended period. The evaluation focused on two aspects of the 1982-built car shells. First, what is the current and predicted condition of the shells and, second, how does the performance of the current car shell design compare to present day designs and requirements? Four sets of activities were done as part of this project. One-third of the fleet was randomly chosen for visual inspections. Service-induced cracks were identified at two locations: in ring welds below the doors, and on the side sill between the corner posts and the anti-climbers. The ring weld cracks have been identified on a small number of cars in the past, and SEPTA continues to monitor and reinforce these areas. The cracks between the corner posts and anticlimbers are also being monitored; to date, none of these cracks has progressed to the point that repair is required. In parallel with the visual inspections, the car shell camber and doorway dimensions were measured on approximately 10% of the fleet. All the measured vehicles had positive camber; doorway dimensions were uniform, except for scattered individual measurements that were car-specific. This part of the evaluation concluded that the car shells are not undergoing significant degradation or cracking. One car was instrumented with strain gauges in potential high-stress areas, and then operated at simulated full passenger-load weight over the Broad Street route. Cyclic strains imposed by simulated revenue service were measured and converted to stresses. This testing confirmed high stresses at the joint between the side sill and the body bolster. The lifetime limiting location on the car shells is in the ring welds below the doors, consistent with the results of the visual inspections. Using conservative assumptions of continuous full passenger loading and minimum material properties, the predicted lifetime to the initiation of visible cracks in this area is 7–14 years of service. This independent evaluation is consistent with the actual experience, and provided confidence in the analysis protocol. SEPTA is monitoring this location and repairing cracks as required. Evaluation of the car shell design with regard to performance in a collision revealed that, unlike most other cars of its era, the Broad Street car shell contains provisions to manage energy absorption during a low-speed collision. Records obtained from a car repair shop showed that, when a Broad Street car had a significant non-revenue end collision, these provisions worked as intended to localize the deformation. In similar collisions, the Broad Street car shell will not perform significantly different from cars built to current industry practices. Results from this study indicate that with continued attention to car shell condition, including regular inspections and limited repairs, the Broad Street car shells will continue to be safe and serviceable for an extended period.

Freight rail carriers have been continuously challenged to reduce costs and comply with increasingly stringent environmental standards, into a continuously competing and environmentally driven industry. In this context, current availability and relative abundance of clean and low cost non conventional gas reserves have aroused a comprehensive reevaluation of rail industry into fuel option, especially where freight rail are strongly diesel based. Countries in which rail sector is required to play an important role in transport matrix, where fuel expenditures currently accounts for a significant share of operational costs, like Australia, Brazil, United States and other continental countries, can be seen as strong candidates to adopt fuel alternatives to diesel fueled freight railways. Moreover, from an environmental perspective, the use of alternative fuels (like natural gas) for locomotive traction may allow rail freight carriers to comply with emission standards into a less technologically complex and costly way. In this context, liquefied natural gas (LNG) fueled freight locomotives are seen as a strong potential near-term driver for natural gas use in rail sector, with its intrinsic cost and environmental benefits and with the potential to revolutionize rail industry much like the transition from steam to diesel experienced into the fifties, as well as the more recent advent of use of alternating current diesel-electric locomotives. LNG rail fueled approach has been focused on both retrofitting existing locomotive diesel engines, as well as on original manufactured engines. Given the lower polluting potential of natural gas heavy engines, when compared to diesel counterparts, LNG locomotives can be used to comply with increasingly restrictive Particulate Matter (PM) and Nitrogen Oxides (NO x ) emission standards with less technological complexity (engine design and aftertreatment hardware) and their intrinsic lower associated costs. Prior to commercial operation of LNG locomotives, there are some technical, operational and economic hurdles that need to be addressed, i.e. : i) locomotive engine and fuel tender car technological maturity and reliability improvement; ii) regulation improvement, basically focused on operational safety and interchange operations; iii) current and long term diesel - gas price differential, a decisive driver, and, finally, iv) LNG infrastructure requirements (fueling facilities, locomotives and tender car specifications). This work involved an extensive research into already published works to present an overview of LNG use in freight rail industry into a technical, operational and economical perspective, followed by a critical evaluation of its potential into some relevant freight rail markets, such as United States, Brazil and Australia, as well as some European non electrified rail freight lines.

While experience is often the best teacher, learning from precursors is much less painful. The aviation and health care industries have greatly benefited from proactively analyzing and developing measures to address sentinel events and learning from various data sources. Such reflective learning is typical of High Reliability Organizations (HROs) with strong learning cultures. As technology like Positive Train Control increasingly integrates into the rail industry, the resulting data they inevitably produce can provide a wealth of knowledge that can greatly improve safety if the data streams are well managed and not blindly mined. For example, simulators generate data while locomotive engineers use them. During training, such data can indicate weak points where the engineer can improve. Examining such data over multiple engineers can establish general areas of strengths and weaknesses among trainees where instructors can place more or less focus and develop better overall training options. Such data could potentially be used to improve cab design and establish how trains and cab care would operate along a given rail line. This paper will explore the use of data streams from various sources, including those currently used like injury reports, emerging ones like simulation training evaluations and data logs to develop better safety cultures within the rail industry.

Safety as the key quality property among RAMS (reliability, availability, maintainability, and safety) demonstrates the most stringent performance in correspondence with the safety requirements and performance standards like EN 50126. Meanwhile, GNSS (Global Navigation Satellite Systems) are penetrating the railway now widely in non-safety related applications as passenger information, fleet management, etc. GNSS also have great potential for safety-related applications in railway such as the train location determination function, which the safety performance needs to be assured through hazard analysis and risk assessment process. The train location determination by satellite-based localization system is elevating the train control to the next level. The European Train Control System (ETCS) has being trying to implementing Level 3, the Chinese Train Control System (CTCS) has been implementing CTCS Level 3 low cost especially for secondary lines, and the U.S. is implementing train control systems under Positive Train Control (PTC) requirements. The train control system needs GNSS to provide more accurate location information of trains, more flexible and condensed trains on tracks with the consistency of still keeping the current safety level or even improve safety. Some researchers are trying to understand the performance of GNSS (GPS / EGNOS / Beidou) for railway applications from the fundamental accuracy level. A satellite-based train localization unit (SaLuT) as the entity to perform the train location determination function is to bring the GNSS accuracy evaluation up to safety integrity according to the safety requirements and standards for risk assessment. One of the key consequential result derived from the train location is the adequate safety margin. The safety margin, which can also be called as “safe braking distance”, is a margin indicated to rail traffic that would allow the train to stop with the application of normal service braking. The safety margin estimation quality and the risk of the safety margin shows the hazard rate for the safety margin estimation function performed by the designed localization unit SaLuT. This paper discusses the safety margin estimation method considering both GNSS accuracy and integrity assessment aspects of SaLuT, in accordance of the settled safety requirements of location determination function. To analyze the hazard of the safety margin estimation, a formal method is applied to model the SaLuT behavior and functions. The formal method based on stochastic Petri net enables the modeling process to include the GNSS receiver collected real data on the test track into it. The safety margin estimation method together with the risk assessment method using the real data can generate quantitative indicators to represent the localization function and safety margin estimation quality. The data used for the analysis is collected in the Qinghai-Tibet railway line from Golmud station to Ganlong station by SaLuT installed on a locomotive along the track. With the stochastic Petri net model and the systematic equation using the real collected data to estimate the safety margin based on the GNSS technologies, the SaLuT can be validated and verified for its hazard rates, which provides information for the safety cases in order to meet the industrial normative requirements.

Integrating Global Navigation Satellite System (GNSS) into railway application has a great potential because of its various advantages, such as lower cost, less trackside equipment, higher positioning accuracy, easier maintenance and so on. Railway system is a safety-critical system that requires high reliability, safety and real-time performance, so GNSS technology must be tested, verified and validated in railway system before putting into practical applications. However, due to the unavoidable restrictions and inconvenience of the railway field conditions, these tests cannot be accomplished on site. On this basis, this paper has developed a GNSS-based train trajectory simulation system which can provide GNSS data simulation of multi-train trajectory in multiple scenarios in order to support the tests and research of GNSS-based railway application, especially GNSS-based train localisation system and GNSS-based train control system. The GNSS-based train trajectory simulation system is based on the railway timetable (also called schedule), rolling stock information and digital track map. The paper firstly researches on the timetable that stores information of each train at each specified station, including arrival time, departure rime, track to be occupied, and connections to other trains. With the timetable simulation, the train’s trajectory can be generated using the information provided by the digital track map. The output trajectory data is mainly GGA sentence which is compliant with the National Marine Electronics Association (NMEA) 0183 standard. The paper also calculates the satellite visibility based on satellite ephemeris to simulate the number of visible satellites during the trajectory with changing time and space. All the information and data, such as timetable, speed/distance curve, distance/time curve, station track occupation state, can be visualized and updated in graphics and diagrams for better view. In addition, the train motion behavior of acceleration, cruising, coasting and braking can also be modelled in the system, as well as the driver’s behavior. The GNSS-based train trajectory simulation system has been realized using C# programming language in Microsoft Visual Studio 2010. And the field data of Shanxi coal railway transportation company railroad is used in the system. The simulation system is tested and the experimental results show that the developed simulation system can perform the expected functions, and provided data source for GNSS-based train localisation system. In addition, this simulation system has a good performance in compatibility and scalability.

This paper investigates the plausibility of a novel in-vehicle auditory alert system to warn drivers of the presence of railroad crossings. Train-Vehicle collisions at highway-rail grade crossings continue to be a major issue despite improvements over the past several decades. In 2014 there were 2,286 highway-rail incidents leading to 852 injuries and 269 fatalities. This marked the first time in the past decade that incident rates increased from the previous year. To prevent the overall trend in safety improvement from plateauing, interest is shifting towards novel warning devices that can be applied to all crossings at minimal cost. These novel warnings are intended to complement but not replace the primary visual warnings that are already in place at both active and passive crossings. Few in-vehicle warning systems have been described and tested in the rail safety literature. The ones that have been described only manipulate the modality or reliability of the warning message, and pay little attention to message content, timing of presentation, mappings between crossing events and warning logic, and driver habituation associated with long term use. To this end, a line of research has been being carried out to design in-vehicle auditory alerts and measure subjective preference and driver behavior in response to in-vehicle auditory alerts. The first study included a subjective evaluation of potential auditory cues. Cues rated as most effective and appropriate were included in the design of prototype systems in the follow up study. The second study will measure compliance rates in a driving simulator with and without in-vehicle auditory alerts. The results of first study and the study design for the second study are discussed.