In the United States, a train moving onto a terminating track at a passenger terminal relies on the train engineer’s operation. Currently, there are no mechanisms installed at the U.S. passenger terminals that are able to automatically stop a train before reaching the end of the track if an engineer fails to do so. The engineer’s actions determine whether the train will safely stop before the end of the terminating track. Thus, incapacitated or inattentive engineer operation would result in end-of-track collisions, such as the New Jersey Transit train accident at Hoboken Terminal in 2016. Currently, PTC enforcement is not required in passenger terminals. In an ongoing project tasked by the Federal Railroad Administration, we study the cost-effectiveness and operational impact of possible PTC enforcement to prevent end-of-track collisions. Specifically, a Concept of Operations (ConOps) was developed to outline the proposed plans to implement two of the most widely used PTC types, namely the Advanced Civil Speed Enforcement System (ACSES) and Interoperable Electronic Train Management System (I-ETMS). This paper describes in-field testing of the ConOps in ACSES-type terminal. In the planned field test, a train equipped with one locomotive and at least one passenger coach would be tested on platform tracks in a selected passenger terminal. These are three major testing components, which are test equipment, test track, and recorded information for each test sequence. Firstly, in terms of equipment, a traffic cone will be placed on the track to simulate a bumping post. In ACSES system, two sets of transponders are programmed to require a positive stop within a specified distance and mounted to the cross ties at specified positions. Secondly, a yard track will be used to test the feasibility of this exercise at the beginning. Upon successfully completing the test multiple times, a series of tests will also be made on the studied platform track. Thirdly, each test run should record the distance from the head end of the test train and the traffic cone for each test run. In addition, ACSES system should also record the information on the ACSES display as it passes the first and second transponder set, respectively. Overall, the field tests presented in this paper, along with previous work in benefit-cost analysis and operational impact assessment, can contribute to an assessment of the proposed PTC implementation at stub-end terminals in the United States in order to effectively and efficiently prevent end-of-track collisions.

Communications-Based Train Control (CBTC) technology is used by transit agencies in large cities to maximize the use of their infrastructure. In comparison with conventional block signal system and cab signaling system, CBTC provides the most efficient capabilities with respect to headway and throughput while being the most economical in terms of maintenance cost [1]. CBTC also provides better diagnostic capabilities compared to traditional signaling systems. It uses limited number of equipment on the trackside compared to traditional signaling systems and allows either a centralized architecture or distributed architecture. For these reasons, CBTC is now the favored system for new lines as well as most signaling system renewals.[1] Despite widely used CBTC standards, the signaling industry is not in agreement regarding what qualifies as a CBTC system and which projects are the first “real” CBTC projects. This work describes the different CBTC vendors, their genesis, when access point based radio was first introduced (access point based radio is also referred by signaling engineers as free space propagation radio), the different consolidations with other CBTC companies, and their major projects. From the authors’ viewpoint, it is appropriate to present the CBTC vendors by geographical areas, for instance in North America: Bombardier Transportation, Thales Rail Signaling Solutions, in Europe: Alstom Transport, Hitachi Rail, Siemens Mobility, in Asia: Beijing Traffic Control Technology, China Railway Signal and Communications, Mitsubishi Electric Corporation, and Nippon Signals.

This paper was written to commemorate the 100th anniversary of the ASME Rail Transportation Division, which was founded in 1920 and held its first meeting in St. Louis. It attempts to paint a picture of the U. S. railroad freight car and the engineering processes involved in its design and construction in 1920 and compare this with today’s designs and practices. Progress in freight car design has been evolutionary rather than revolutionary. The steel freight car had largely replaced its wooden predecessor by 1920 and the basic design of many cars was already in place. Exceptions being the Spine Car and the Well Car, which were entirely unknown in 1920. The Box Car has diminished greatly in importance and more specialized cars are now common. One important difference is that welding is now used extensively in freight car construction whereas in 1920 riveting was almost universal. An important change is the availability of electronic instrumentation to measure, record and analyze the load environment of cars. This has allowed the development of performance-based specifications and these have largely replaced the prescriptive standards used in 1920. CAD and FE analysis have revolutionized the way in which cars are designed, allowing much more refined analysis which has led to far lighter car designs. In 1920 virtually all Engineers were white men — this too is changing.

Laser welding has received increased interest in the rail industry due to its outstanding performance in aesthetics, strength, heat affected area, precise control and sealing. This paper introduces the laser-welded stainless steel carbody used in subway cars. The carbody structure, welding methods, strength and fatigue analysis methods, and test verification and validation results are discussed. Firstly, the shear strength of laser welding on stainless steel with different thickness combinations were obtained through tests. The preliminary carbody structure was designed based on the material and welding properties. Then the finite element analysis (FEA) was conducted on the preliminary design to evaluate the strength and optimize the structure. After the optimization was completed, a full-size car was manufactured, and the strength test was performed. In the process of FEA and strength evaluation, the simulation accuracy of different element types and the influence of loading force directions have been considered. Based on the design, simulation and test data, a complete laser welding carbody strength evaluation system was established, which can provide valuable reference for researchers and engineers in the rail vehicle industry. The entire design, analysis and testing process complies with ASME-RT2-2014 and this is also one of the first to implement this standard.

In this study, a Secondary Impact Protection System (SIPS) consisting of an airbag and a deformable knee bolster for use on a modern freight locomotive was developed and tested. During rail vehicle collisions, a modern locomotive designed to current crashworthiness requirements should provide sufficient survival space to the engineer in cab. However, without additional protection against secondary impacts, a locomotive engineer could be subjected to head, neck, and femur injuries that exceed the limits specified in the Federal Motor Vehicle Safety Standards (FMVSS 208). The SIPS study aimed to design a system that would control these injuries within the limiting criteria. Simulation results for the design concept showed that it would meet the FMVSS 208 criteria for the head, neck, chest, and femur, injuries and continuing to meet all existing functional requirements of the locomotive cab. A sled testing of the prototype showed that to optimize the SIPS, further airbag design modifications, characterization and testing are required.

This paper discusses two real-world challenges faced by Communications-Based Train Control (CBTC) testing programs. a) Why is it that even after a successful complete system Factory Acceptance Test (FAT), the performance of the CBTC system during the first few months of field tests is prone to frequent failures? On some projects, it may be months between a successful FAT and the first operation in CBTC mode. b) How accurately and efficiently can the root cause of failures during the field tests be identified and how could a test program be improved to have a smooth transition from field testing to revenue service. Unlike commissioning a conventional signaling system, where after circuit break down and operation testing are completed, the system works well during revenue service, CBTC projects experience an additional round of ‘surprises’ when the system is put in service after months or years of testing [1]. This comment is valid for both new lines and signaling upgrade projects, it should be noted that signaling upgrade projects are more prone to ‘surprises’ due to the limited track access which reduces testing time. Even though the final test results prior to revenue service indicate no ‘showstoppers’, once system is placed in service, it is common to unearth major issues that impact sustainable revenue operation. Though, as it should, this often comes as a surprise to transit agencies installing CBTC for the first time, it is almost accepted as fate by most of the experienced CBTC engineers. This paper describes the tests performed prior to placing system in revenue service and analyzes some of the issues experienced. Detailed information regarding the field tests can be found in [2]. Description of possible mitigations used by CBTC suppliers and transit agencies are included, as well as likely reasons for such a predictable pattern on CBTC projects. Finally, ideas about how to continue improving the mitigation to minimize the risk of major system issues are presented.

This paper begins with examining the fundamental nature of wayside signals and considers the first know signaling practices used to communicate the condition of the track ahead to the train engineer. The principle of wayside signals is to keep trains separated and to provide knowledge of the conditions ahead; speed and routing information. Most railways have gone through many different evolutions of signals and practices some driven by railway mergers which drove the operating rules. This consistently required changes within the training of locomotive engineers assigned operate trains within their territory. This paper will focus on a few transitions between signal types, the specific makeups and effectiveness of wayside signals since the beginning of railway signals in the early 1830s. Starting with the term “High Ball” not related to a popular drink known today, but a raising of a large ball into the air that could be seen from afar instructing a train his status to train operating schedule. Later, signals were developed to provide the train engineer the status of the track ahead by dividing the track into short sections. This allowed the track section to be labeled as “occupied” a train present or “un-occupied”, train not present within the track section. Wayside signals continued to be advanced such that today’s standards, aspects (mimicking the wayside signals) are displayed within the operating cab providing the indication directly to the engineer. As we continue forward, wayside signals have been reduced and in the future, they may be only in a museum next to the cassette player.

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.

We examine how establishing a competitive Joint Rail Conference Grand Challenges Initiatives can harness the potential of college and possibly high school students to develop solutions or new insight into technical and safety problems plaguing the rail industry, including safety. The rail industry has tended to solve issues internally. However, solutions can often be found in other industries that are either similar or have faced similar concerns. For example, the immediate predecessor of Positive Train Control (PTC), the Advanced Railroad Electronics System (ARES), was conceived in the mid 1980’s by then Burlington Northern Railroad (BN) CEO Richard Bressler, who had read how flight safety and efficiency had been improved by air traffic control systems and avionics developed by Rockwell Collins for the Boeing 757 and 767 aircraft. The information age has further increased the potential for sparking innovation as ideas can spread literally overnight via the internet. Some of the most talented and creative problems solvers are college and high school students, who have been greatly enabled by the “democratization” of information that has given them access to knowledge and skills as never before. Teens can learn nearly any skill watching reputable online videos or even “attend” classes offered by top universities around the world simply using a smart phone or tablet. This has prompted educators like Michigan Tech’s Dr. Pasi Lautala and other to develop extensive online rail educational resources to spark interest in the industry. However, simply passing on information has its limitation, which is why initiatives like the Grand Challenges, and Engineers without Borders have been instrumental in harnessing students to examine key global challenges in engineering, energy, and health care. Moreover, these initiatives have encouraged many students to pursue careers in those fields, even in low- and medium-income countries. For example, in 2012, a high school sophomore developed a new method to detect pancreatic cancer that is quick to administer and detects the disease much more quickly than previous methods, allowing much better chances for successful treatment. We will examine how establishing a competitive JRC Grand Challenges Initiatives can harness the potential of college and possibly high school students to develop solutions or establish new insight into technical and safety problems plaguing the rail industry, including safety. In addition, it will look at how developing a dialog among the rail industry, including the Class 1 railroads, students, and academia can encourage a more top notch, talented students to consider careers in the rail industry.

With the development of high-speed rail technology, the interaction between wheel and track becomes more serious, which threatens the running stability, riding quality and safety of the vehicle. Due to the selected stiffness and damping parameters, conventional passive suspensions cannot fit in with the diverse conditions of the railway. Additionally, among these vibrations contains a large amount of energy, if this vibrational energy can be recycled and used for the active suspension to control, it will be a good solution compared to the conventional passive suspensions. Many energy-harvesting shock absorbers have been proposed in recent years, the most popular design is the electromagnetic harvester including linear electromagnetic shock absorbers, rotational electromagnetic shock absorbers, the mechanical motion rectifier (MMR), and the hydraulic electromagnetic energy-regenerative shock absorber (HESA). With different energy converting mechanisms, the complicated effects of the inertia and nonlinear damping behaviors will severely impact the vehicle dynamic performance such as the ride comfort and road handling. In the past few years, engineers and researchers have done relevant researches on HESA which have shown that it has good effects and proposed several suspension energy regeneration solutions for applying to car. This paper presents a novel application of HESA into a bogie system for railway vehicles comparing to the conventional suspension systems. HESA is composed of hydraulic cylinder, check valves, accumulators, hydraulic motor, generator, pipelines and so on. In HESA, the high-pressure oil which is produced by shock absorber reciprocation could be exported to drive the hydraulic motor, so as to drive the generator to generate electricity. In this way, HESA regenerate the mechanical vibrational energy that is otherwise dissipated by the traditional shock absorber as heat energy. Because the bogie has two sets of suspension systems, a dynamic model of bogie based on AMESim is established in order to clarify the influence of the dynamic characteristics effect and the energy harvesting efficiency when installing the HESA into different sets of the bogie. Then, set the HESA model into each suspension system of the bogie and input with the corresponding characteristic excitation, the influence of the dynamic characteristics and the energy harvesting efficiency are analyzed and compared. The simulation results show that the system can effectively reduce the vibration of the carriage, while maintaining good potential to recycle vibratory energy. Based on the results of the simulation, the relationships as well as differences between the first suspension system and second suspension system have been concluded, which are useful for the design of HESA-Bogie. Moreover, comparing the energy harvesting efficiency discrepancy between the two suspension systems, the potential of energy harvesting of a novel railway vehicle bogie system with HESA has been evaluated and then the best application department has been found, which indicates the theoretical feasibilities of the HESA-bogie to improve the fuel economy.

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.

Union Pacific Railroad’s Moffat Tunnel Subdivision, west of Denver, Colorado, was significantly impacted by an approximately 500 to 1,000 year storm event that occurred between September 9, 2013 and September 13, 2013. As a result of this historic event, washouts, earth slides, and debris flows severely impacted track infrastructure by eroding track embankments, destabilizing surrounding native slopes, and overwhelming stormwater infrastructure. Emergency response activities performed to restore track operations at Milepost (MP) 25.65 and MP 22.86 required the integration of civil, hydraulic, environmental and geotechnical engineering disciplines into emergency response and construction management efforts. Additionally, support from UPRR’s Real Estate Division was required when addressing private ownership and site access issues. The following text summarizes how coordinated efforts between various groups worked together in a pressure setting to restore rail service. The most significant damage occurred at MP 25.65 in a mountainous slot canyon between two tunnels accessible only by rail and consisted of a washout, approximately 200 feet (61 m) in length with a depth of 100 feet (30 m). MP 22.86 experienced slides on both sides of the track resulting in an unstable and near vertical track embankment which required significant fill and rock armoring. In addition to the embankment failures at MP 22.86, flood flows scoured around the underlying creek culvert, further threatening the geotechnical stability of the track embankment. The storm event highlighted the vulnerability of fill sections, where original construction used trestles. The repair plan engineered for MP 25.65 was developed to restore the lost embankment fill to near pre-flood conditions while limiting environmental impacts in order to minimize regulatory permitting requirements. Fill replacement performed during the initial emergency response was completed within 22 days, notwithstanding site remoteness and difficult access. Repair of the embankment required the placement of approximately 90,000 cubic yards (68,800 cubic meters) of fill and installation of four 48-inch (122-cm) culverts. Repair of embankment sloughing and scour damage at MP 22.86 was accomplished without the need for environmental permits by working from above the ordinary high water mark, using a “one track in – one track out” approach while restoring infrastructure to pre-flood conditions. A new headwall to address flow around the culvert inlet received expedited permit authorization from the U.S. Army Corps of Engineers by limiting the construction footprint through implementation of best management practices and minimizing placement of fill below the ordinary high water mark. Service interruptions, such as those at MP 22.86 and MP 25.65, require sound engineering practices that can be quickly and efficiently implemented during emergency response situations that often occur in less than ideal working environments. Track outages not only impact the efficiency of a railroad’s operating network, but also impact interstate and global commerce as transportation of goods are hindered. The need to have a team of experienced engineering and construction professionals responding to natural disasters was demonstrated by this storm event.

Analysis of contact points between wheel and rail during the wheel climb is of interest to railroad application engineers. In this study the climb maneuver of a wheelset is modeled in a general purpose multi-body system computer program. This model then is used to generate the contact data for a climbing wheelset. A graphical user interface is developed which uses this contact data and generates several contact points charts. In developing the graphical user interface, mouse and keyboard events as well as other controls are used to make the interface interactive and intuitive.

High-risk organizations operate technologies such as in rail transportation, aviation, or nuclear power, where failure/breakdown can initiate low-probability, high consequence events. The concept of High-Reliability Organizations (HROs) was developed to avoid or mitigate such events through proper management despite the inherent risk. The September 12, 2008, Chatsworth accident is an example of such events that HROs are designed to prevent. In that case a Metrolink commuter train and Union Pacific freight train collided when the Metrolink engineer failed to recognize and react to a stop signal as a result of texting, causing 25 deaths and 135 injuries. This incident directly resulted in the Railroad Safety Improvement Act of 2008, which mandated Positive Train Control (PTC) implementation on all Class 1 rail carriers, as well as intercity / commuter rail passenger transporters. Over the past 2 years, the USC team has observed PTC implementation at the Southern California Regional Rail Authority (SCRRA) / Metrolink. This paper examines how PTC can be an integral part in developing and promoting HRO principles within the rail industry based on those observations.

In November, 2005 before an assembly of rail transit managers and engineers, keynote speaker Tom Prendergast — then Vice President, Parsons Brinckerhoff T&RS — declared that the next frontier of railway engineering would be not in the “Big Four” engineering disciplines of Civil, Mechanical, Electrical or even Computer Engineering, but in “Integration Engineering.” Years have passed and while Tom’s words have not yet been fully realized by the transit industry, change is happening. Today, railway construction projects that have had major construction issues include the now beleaguered Edinburgh, Scotland “Edinburgh Tram” and the recently opened Hampton Roads Transit “Tide” Light Rail. Both projects have suffered from major cost overruns, work stoppages and legal entanglements, much of which can be attributed to a lack of scope clarity, especially utility identification & interfaces, and utility relocations. The lack of coordination for both projects can be traced back to the preliminary engineering level and continued, unchecked through final design and into construction where the lack of coordination and planning was realized too late. [1,2] Given the complexities of modern railway systems and the well-developed urban and suburban infrastructure where they are typically built, proper integration engineering is essential from the earliest phases of a project and should be carried through to the start of revenue operations and maintenance. There are however, examples of recently completed railway projects that have addressed project integration engineering successfully, finishing ahead of schedule, ahead of budget, or both. This paper is a continuation in a short series of presentations and papers that will address Railway Project Integration Engineering as a topic and recommend the integration tasks deemed critical to a successful project. The primary subject matter will be the Denver Eagle P3 — the first rail transit Public Private Partnership (P3) in the United States that has recently completed final design and is currently under construction. The materials and techniques to be presented are relatively new, and have already been used successfully in Europe. Should they prove successful with the Eagle P3, this could lower both cost and risk for future North American rail projects. This first paper will discuss the topic, review modeling techniques that were used to define the project integration process, and will capture the results of final design integration with both successes and difficulties. This paper will also cover the early stages of the Eagle P3 project construction, tie into the model, and attempt to project likely results when construction concludes and testing begins with the ultimate goal of meeting an ambitious schedule and budget when operations commence in January, 2016.

The current American Railway Engineering and Maintenance-of-Way Association (AREMA) Manual provides live load impact formulas for the design of steel railroad bridges. The only variable in those formulas is span length and do not include other parameters that bridge engineers know affects live load impact factor. Years of use in practice and research have shown that these formulas are reliable, safe and simple to apply, though often very conservative. In order to make the nation’s transportation more efficient and energy efficient, a significant effort is underway in the U.S. to enhance its railroad infrastructures. Bridges built before the 1950s, many of which are still in service, were designed to sustain the effects of steam engine hammer blow, and consequently slow speed. Yet, most of these bridges may not be replaced and may be required to carry high speed passenger equipment. This raises the question of what effects higher speed trains will have on old, long span truss steel bridges. This paper presents finding from the detail literature review on the current live load impact factor on truss railroad bridges and its implication to the future.

This research program was sponsored by the Federal Railroad Administration (FRA) Office of Research and Development in support of the advancement of improved safety standards for passenger rail vehicles. In a train collision, the cab or locomotive engineer is in a vulnerable position at the leading end of the vehicle. As cars with increased crashworthiness are introduced into service, there is a greater potential to preserve the space occupied by the engineer following an accident. In particular, full-scale impact tests have demonstrated the engineer’s space can be preserved at closing speeds up to 30 mph. When sufficient survival space is preserved, the next objective is to protect the engineer from the forces and accelerations associated with secondary impacts between the engineer and the control cab. Given the hard surfaces and protruding knobs in a control cab, even a low speed collision can result in large, concentrated forces acting upon the engineer. Researchers have designed a passive (i.e., requiring no action by the operator) interior protection system for cab car and locomotive engineers. The occupant protection system will protect engineers from the secondary impact that occurs following a frontal train impact, when the engineer impacts the control console. The protection system will result in compartmentalization of a 95th percentile anthropomorphic test device (ATD), and measured injury criteria for the ATD’s head, chest, neck, and femur that are below those currently specified in Federal Motor Vehicle Safety Standard (FMVSS) 208 [1]. The system that has been developed to protect the engineer includes a specialized airbag and a knee bolster with energy absorbing honeycomb material and deformable brackets. Finite element and lumped mass-spring analyses show the effectiveness of the system in limiting the injury criteria to survivable limits. Component tests have measured the key characteristics of the airbag and the knee brackets and have provided test data necessary to validate the analyses. Two tests were conducted to validate the airbag model. A static deployment test of the airbag measured the inflation progression, the inflated shape and the internal pressure of the airbag. A drop tower test of the airbag measured the force-crush and energy absorbing characteristics of the airbag. The knee bolster assembly consists of two components. Separate quasi-static tests of the aluminum honeycomb and the knee bolster bracket measured the force-crush and energy absorbing characteristics. The component test results were used to improve the computer model and permit analysis of the entire system. This paper discusses the prototype design, including background research, baseline definition and prototype development. The initial prototype design is analyzed using computer models. The components are tested to verify and improve the computer models. The test and analysis results are presented. Future work is planned for fabrication of the cab desk and prototype system to be used in a sled test with a 95 th percentile ATD.

Locomotives produce vibrations and mechanical shocks from irregularities in the track, structural dynamics, the engines, the trucks, and train slack movement (Mansfield, 2005). The different directions of the irregularities give rise to car-body vibrations in multiple axes including the following: • longitudinal, or along the length of the train (x); • lateral, or the side-to-side direction of the train (y); • vertical (z). The structural dynamics of rail vehicles give rise to several resonances in the 0.5–20Hz frequency range (Andersson, et al., 2005). Resonances are frequencies in the locomotive that cause larger amplitude oscillations. At these frequencies, even small-amplitude input vibration can produce large output oscillations. Further exacerbating the vibration environment, coupling of the axes of movement occurs: Motions in one direction contribute to motion in a different direction. The magnitude of vertical vibration in rail vehicles is reportedly well below many other types of vehicles (Dupuis & Zerlett, 1986; Griffin, 1990; Johanning, 1998). However, a lack of data from long-haul freight operations prevents an adequate characterization of the vibration environment of locomotive cabs. The authors describe results from 2 long-haul whole-body vibration (WBV) studies collected on a 2009 GE ES44C4 locomotive and a 2008 EMD SD70ACe. These WBV studies sponsored by the Federal Railroad Administration (FRA) examined WBV and shock in locomotives over 123 hours and 2274 track miles. The researchers recorded vibration data using 2 triaxial accelerometers on the engineers’ seat: a seat pad accelerometer placed on the seat cushion and a frame accelerometer attached to the seat frame at the base. The research team collected and analyzed vibrations in accordance with ISO 2631-1 and ISO 2631-5. ISO 2631-1 defines methods for the measurement of periodic, random and transient WBV. The focus of ISO 2631-5 is to evaluate the exposure of a seated person to multiple mechanical shocks from seat pad measurements. Exposure to excessive vibration is associated with an increased occupational risk of fatigue-related musculoskeletal injury and disruption of the vestibular system. While this is not an established causal relationship, it is possible that vibration approaching the ISO 2631-1 health caution guidance zones may lead to an increased occupational risk. The results from these rides show that the frequency-weighted ISO 2631 metrics are below the established health guidance caution zones of the WBV ISO 2631 standards. The goals of these studies are to: • collect data in accordance with international standards so results can be compared with similar findings in the literature for shorter duration rides as well as vibration studies in other transportation modes, • to characterize vibration and shock in a representative sample of locomotive operations to be able to generalize the results across the industry, and • collect benchmark data for future locomotive cab ride-quality standards.

The interoperable positive train control (PTC) system uses radio frequency (RF) in the 220 MHz band for wireless communications. Robust and reliable 220 MHz RF communication is critical to the success of the interoperable PTC system. To ensure proper operation of the interoperable PTC system, it is thus crucial to properly engineer and evaluate RF performance of communications from wayside devices and base stations to trains operating along PTC controlled track. This paper presents a design of wireless communications over the 220 MHz band for the interoperable PTC system. Performance of the designed 220 MHz PTC communications is analyzed and theoretical predictions are provided. The paper also presents a simulation system architecture for analyzing the performance of PTC communications over the 220 MHz band. The simulation system test bed integrates a message generator, RF channel simulator, and PTC software-defined radio prototypes configured as a base, locomotive, or wayside radio. Extensive simulations were conducted to determine RF performance of PTC radio communications in various scenarios including flat terrain and city environments. Simulation results are given and compared to the theoretical predictions.

As U.S. states are planning and designing for future nationwide and regional high-speed rail (HSR) services, an important issue to consider is where to locate stations. Station location determination is critical not only because it influences the perceived utility of the HSR services and can greatly influence ridership, but also due to its impact upon the local and regional transportation mobility, land use, and urban economic development. The main purpose of this paper is to provide information to HSR planners, engineers, and decision-makers in the U.S. on the practices of other countries in locating HSR stations. This paper examines HSR stations in several of the earliest countries which built HSR infrastructures: France, Spain, and Japan, to analyze how HSR station locations were selected, as well as the applicability of those methodologies in the planning process for the United States.