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Early identification of wheel defects can prevent serious damage to railways, considerably lowering maintenance costs for both railway administrations and rolling stock operators. Within this context, an unsupervised methodology based on artificial intelligence techniques is presented, which allows the detection and classification of out-of-roundness damage wheels, such as wheel flats and polygonal wheels, based on dynamic responses induced on the track by crossing freight railway vehicles. The methodology involves the following steps: (i) data collection and pre-processing, (ii) feature extraction (iii) data fusion and (iv) feature discrimination. In the first phase, an FFT algorithm is applied to the acceleration track responses. Then, features are extracted after training a Stacked Sparse Autoencoder, in which the main features of the responses are obtained after a compression stage using an encoder network. This lower dimensional layer forces the model to learn a compression of the input data. Then, these extracted features are merged using the Mahalanobis distance, which enhances the sensitivity to the damage recognition. Posteriorly, an outlier analysis is performed to distinguish a healthy wheel from a defective one and a cluster analysis to discriminate the two types of out-of-roundness (OOR) damage and classify the severity of each type of damage. [ABSTRACT FROM AUTHOR]

This study examines the evolution of China’s collective contract system from 1979 to 1992, a period marked by the country’s transition from a centrally planned to a market-oriented economy. Utilizing institutional theory, specifically the concepts of institutional voids, transitions, and strategic choices, we analyze how collective contracts emerged and adapted to address distinct regulatory challenges in foreign-invested enterprises (FIEs) and state-owned enterprises (SOEs) during the early reform era. Through case studies of Beijing Jeep and the Shenyang Locomotive and Rolling Stock Plant, we demonstrate that these contracts initially served as functional mechanisms for regulating labor relations and filling institutional voids in a dual-track economy. However, the system’s eventual decline into symbolic formalism by the mid-1990s reveals the limitations of strategic adaptation in the face of rapid, discontinuous institutional transitions driven by accelerated market reforms and the standardization of labor laws. Our findings highlights the complex interplay between institutional context, strategic choices, and the effectiveness of collective labor regulation in transitional economies, offering valuable lessons for policymakers and labor advocates navigating similar institutional changes. [ABSTRACT FROM AUTHOR]

Within the metro networks of agglomerations all over the world, circle lines play important roles with respect to network connectivity and passenger transfer. The train rescheduling problem of a metro circle line under small disturbances is considered in this paper, including response rules for inserting standby trains, using storage tracks, and holding. A mixed-integer nonlinear programming model is proposed, aiming to minimize timetable deviations, headway variations, number of cancelled stops, and number of rolling stocks, which is then transformed into a mixed-integer linear programming (MILP) model. Furthermore, we enrich our optimization model by including the practical 'snowball effect', depicting the phenomenon that the first delayed train behind the gap is likely to accumulate more delays due to longer dwell times caused by more waiting passengers on platforms. In particular, our solutions suggest that the impact of small delays can be heavily underestimated when ignoring the snowball effect. [ABSTRACT FROM AUTHOR]

This study adopts a hybrid rolling stock composition strategy and proposes a mixed-integer linear programming (MILP) model to optimize the rolling stock compositions together with the train timetable according to real-life passenger demand. The optimization objectives are to minimize the number of stranded passengers and rolling stocks. Two types of constraints are included: constraints related to timetabling and constraints related to passenger assignment. In addition, timetable optimization is used for mixed traffic, including local and express train services. Express trains overtake local trains at specific stations; therefore mapping constraints are built to match each train service to the corresponding train order at different stations to ensure a correct passenger assignment. Numerical examples based on the Shanghai Metro Line 16 are implemented to demonstrate the efficiency of the proposed model. The optimization results show that the proposed method can efficiently reduce the number of stranded passengers and the number of rolling stocks required. [ABSTRACT FROM AUTHOR]

This paper presents a big data-based analysis of the rail wear of the whole Belgian railway network measured in 2012 and 2019. Wear rates are reported, discussed, and quantitatively formulated as functions of critical factors in terms of curve radius, annual tonnage (rail age), high rail in curves, an average from both rails in straight tracks at rail top (vertical wear) and gauge corner (45° wear) and for steel grade R200 and R260. The influence of preventive grinding is also analysed. The wear rates are derived in an aggregated manner for the whole network. The wear rates do not show significant change with changes in rolling stock over the years, implying that the wear rates could also hold for other networks. It is found that R200 shows, on average, a 34% higher wear rate than R260. Also, the wear rate per tonnage is lower for high-loaded tracks. Thus, time is a relevant factor in explaining the wear evolution of low-loaded tracks; for instance, the effect of corrosion may have an important role. The paper provides statistically significant information that can be used for wear modelling, understanding and treating rolling contact fatigue based on the wear rate and developing tailored rail maintenance strategies. [ABSTRACT FROM AUTHOR]

This paper addresses timetable disruptions in metro systems and their impact on passenger service quality. To mitigate these effects, the study introduces a time-space network-based traffic management approach with a two-layer network. The first layer focuses on timetable rescheduling, using an integer program for modeling and a Lagrangian relaxation-based heuristic for solution. The second layer addresses rolling stock duty rescheduling, employing a greedy heuristic for train set duties. The proposed approach is applied to a real-world problem presented in the INFORMS railway application competition (2022). Results demonstrate that, with topological vertex orders, the approach achieves schedule amendments within 3–6 minutes for various disruption scenarios. This rapid response highlights the method's efficacy and advantage in real-time applications, showcasing its potential for practical implementation in metro systems. [ABSTRACT FROM AUTHOR]

Disturbance occurs inevitably on a metro line, resulting in train delays and low service quality. To improve the efficiency of disturbance management, this article investigates the integrated rescheduling problem of train timetable and rolling stock circulation. To balance service quality and operational cost, the considered problem is formulated as a multi-objective optimization model by capturing train operation processes as running arcs, dwell arcs and coming-out/back arcs based on the classical space–time network. For the purpose of improving computational efficiency, a Q-learning-based solution approach is proposed to derive a hierarchical policy for integrated rescheduling. The decisions on train timetable follow a lower-level policy that can be learned in the pre-training process, and the decisions on rolling stock circulation follow a higher-level policy that can be generated in the real-time planning process. Finally, two sets of numerical examples are carried out to evaluate the proposed method. [ABSTRACT FROM AUTHOR]

High-speed trains have to undergo special maintenance services. The maintenance service is highly specialized and can only run on specific platforms. Most of the optimization models proposed in the literature do not consider this problem integrated with the rolling-stock planning, although the two problems affect each other, and their separation leads to suboptimal solutions of the overall problem. This article presents an integrated approach based on a mixed integer mathematical formulation and computational results on a testbed of instances, derived from a real-world case study. This approach is compared with a two-stage one, commonly used in practice and in the literature. The results show that the rolling-stock planning problem can produce input parameters for the scheduling problem for which no feasible schedules exist. When a scheduling solution exists, the final percentage gap of the two-stage solution is much higher than the one provided by the integrated model. [ABSTRACT FROM AUTHOR]

Occupant impact safety is critical for train development. This paper proposes a systematic procedure for developing validated numerical occupant crash scenarios for high-speed trains by integrating experimental, computational, and inverse methods. As the train interior is the most potentially injury-causing factor, the material properties were acquired by mechanical tests, and constitutive models were calibrated using inverse methods. The validity of the seat material constitutive model was further verified via drop tower tests. Finite element (FE) and multibody (MB) models of train occupant-seat interactions in frontal impact were established in LS-DYNA and MADYMO software, respectively, using the experimentally acquired materials/mechanical characteristics. Three dummy sled crash tests with different folding table and backrest configurations were conducted to validate the numerical occupant-seat models and to further assess occupant injury in train collisions. The occupant impact responses between dummy tests and simulations were quantitatively compared using a correlation and analysis (CORA) objective rating method. Results indicated that the experimentally calibrated numerical seat-occupant models could effectively reproduce the occupant responses in bullet train collisions (CORA scores >80%). Compared with the train seat-occupant MB model, the FE model could simulate the head acceleration with slightly more acceptable fidelity, however, the FE model CORA scores were slightly less than for the MB models. The maximum head acceleration was 30 g but the maximum HIC score was 17.4. When opening the folding table, the occupant's chest injury was not obvious, but the neck-table contact and "chokehold" may potentially be severe and require further assessment. This study demonstrates the value of experimental data for occupant-seat model interactions in train collisions and provides practical help for train interior safety design and formulation of standards for rolling stock interior passive safety. [ABSTRACT FROM AUTHOR]

Comfort on railway vehicles has been proven to depend on the number of passengers on the car, on their seating arrangement, as well as on the position in which it is assessed. The number of possible seating arrangement combinations is so large that comfort at a given location becomes a random variable even if passengers are considered deterministic vibration absorbers. In this paper we determine probability density functions (PDF) of comfort using a Monte Carlo scheme in which the number of passengers, their seating locations and their vibration characteristics (derived from passenger mass) are all random parameters with their own PDFs. Two types of distributions are obtained: the expected comfort of a single passenger and the compound comfort of all passengers on a given railway car. The carbody is represented by a beam model in which the first bending mode frequency has been allowed to vary so that the scope of results widens slightly. This variation is within the range of human sensitivity because this is the case in current lightweight construction, making carbody flexibility a key contributor to passenger comfort (or discomfort). Results confirm that comfort is indeed a stochastic variable with sizeable variance, and this prompts questions about the relation between the stochastic distribution and the tests prescribed in standard EN–12299. It will be shown that, surprisingly, comfort PDFs may be inferred with a high degree of accuracy (errors lower than 2%) from the tests in standard EN–12299. This is a most fortunate finding that radically transforms the interpretation of said standard, and allows rolling stock manufacturers and rail transport operators to have a much richer assessment of comfort on their vehicles from the same tests they now conduct, without having to perform Monte Carlo tests or simulations. [ABSTRACT FROM AUTHOR]

Wheel defects can induce damage to the railway tracks, increasing considerable maintenance costs for both railway administrations and rolling stock operators. This paper aims to develop an unsupervised early damage detection methodology, capable of automatically distinguishing a defective wheel from a healthy one, with respect to the small flat size. The proposed methodology is based on the acceleration and shear time histories evaluated on the rails for the passage of traffic loads, and involves the following steps: (i) data acquisition from sensors; (ii) feature extraction from acquired responses with continuous wavelet transform (CWT) model; (iii) feature normalisation to suppress environmental and operational variations; (iv) data fusion to merge the features from each sensor and enhance sensitivity to detect wheel defects; and (v) feature classification to classify the extracted features into two categories: a healthy wheel or a defective one. The shear and acceleration measurement points are strategically defined in order to examine the sensitivity of the proposed methodology, not only to the type of sensors, but also to the position where they are installed. It has been demonstrated that one sensor can detect a defective wheel automatically, allowing the development of an easy-to-implement low-cost monitoring system. [ABSTRACT FROM AUTHOR]

The article presents the results of theoretical studies of interaction process of a freight car body with a three-piece bogie, which are aimed at solving the relevant problem of increasing the permissible speeds at railways with 1520 mm track gauge under conditions of linear load increase on the wheel set axle. The purpose of the research was to propose such an approach to the study of interaction processes between rolling stock and track, taking into account the interaction model of neighbouring carriages in trains, which will allow more correctly take into account the dynamics of rolling stock and increase traffic safety. The oscillation frequencies of the body, bogie and wheel set are analysed in order to establish a possible resonance phenomenon. The article examines the longitudinal and transverse forces of pseudo-sliding (creeping) arising between the climbing wheel of the front bogie and the rails. The conducted studies can contribute to the replacement of 18-100 bogies with modernised three-piece bogies while maintaining the main most metal-consuming elements of the 18-100 model implementing some modernisation units. The results obtained will make it possible to revise the permissible vehicle speeds with an increased axle load. [ABSTRACT FROM AUTHOR]

Rolling stock approval protocols, such as UIC 518, demand monitoring of lateral and vertical forces at rail-wheel contact. Continuous monitoring through on-board instrumentation needs algorithms to convert the on-board sensor data into rail-wheel forces and track irregularities. In this work a Feed Forward Neural Network architecture, for fast and accurate estimation of rail-wheel forces and track irregularities from data obtained from a cluster of accelerometers mounted on the rolling stock, is presented. Simulation study is conducted for a passenger coach running over numerically generated set of one hundred rail tracks, each with a different irregularity. Power spectral density (PSD) function of ERRI B176 is used for creating rail irregularities. Multi-body rail coach model consists of wheel-sets, axle-box, bogie, bolster and car body. The input comprises acceleration, yaw and roll rate data from axle-box, bogie and car body, to produce contact forces and rail irregularities as outputs. Goodness of fit between actual and estimated values is illustrated through point-by-point graphs of actual and estimated track forces and irregularities. R-Squared ( R 2 ) values, representing the fraction by which the variance of errors are less than the variance of actual values, are computed as indices of the accuracy of estimates. [ABSTRACT FROM AUTHOR]

Friction stir welding is a solid-state welding process used to join similar or dissimilar materials. It was used in applications where excellent mechanical properties are needed with less distortion and improved safety. Its main applications are shipbuilding, offshore, rolling stock for railways, automotive, aerospace, general fabrication robotics, etc. Friction stir welding studies of aluminium with copper are reviewed here. Friction stir welding of different heat-treated aluminium alloys with commercially pure copper had been carried out and studied by researchers. [ABSTRACT FROM AUTHOR]

The large tonnage mines use railway transportation as a system for mineral transportation. The rolling stock health condition study and improvement not only reduce the lifecycle cost of the assets but also ensures safe, reliable, punctual, and efficient transportation. The remaining useful life estimation is an efficient approach to condition-based maintenance, prognostics, and health management. This paper aims to predict the remaining life of a mining rolling stocks in the presence of operational environmental effects. In this study, the operation and failure data were obtained from Malmbana, LKAB, Sweden, a Swedish Railway Company, considering the effective operational factors. The failure behaviour of the railcar was evaluated and then the proportional hazard model was used to estimate the conditional reliability functions and accordingly the remaining useful life at the various initial survival time. Finally, the reliability-based time interval is applied to plan the maintenance operations. Results of this study show that the operator's skill level and the maintenance quality had a significant influence on the reliability performance. By considering the proposed PM plan according to the desired reliability level, the remaining lifetime of the rolling stock will be improved by 78.10%, on average. [ABSTRACT FROM AUTHOR]

Due to the increasing demand for safer and faster rail transport, train wheelsets operating under high axle loads require more careful and reliable inspections and maintenance. During service, the train wheelsets are constantly operating under harsh conditions such as fatigue, thermal variation and impact. The wheel defects can induce damage to railway tracks or even derailments, increasing costs for both railway administrations and rolling stock operators. Therefore, early detection of wheel defects may prevent significant damages that could lead to service interruptions or derailments. The purpose of this research is to present an approach to detect the presence of wheel flats using an envelope spectrum analysis, as well as to test, discuss and analyse the sensitivity of the proposed approach to the unevenness of the track, the random position of the wheel flat impact occurrence and the severity of the flat. Subsequently, the sensitivity of the proposed method is tested to accurately detect a wheel flat when the signal is perturbed by different noise intensities. A wide range of 3D simulations based on a train–track interaction model has been performed for different train speeds and different types of flat geometries. From the obtained results, it is evident that envelope spectrum analysis is a capable tool and a cost-effective method that can be used to detect wheel flats along with the flat impact frequency for different train speeds in real-world conditions. [ABSTRACT FROM AUTHOR]

Empty wagon redistribution, train formation, routing and scheduling are complex problems for large railways, many of which currently have or are planning dedicated freight railway corridors (DFC). DFC operations due to their unique characteristics require research and new models for better operations planning. The rolling-stock, being expensive assets, need to be utilised in an optimal manner while meeting service quality levels. Motivated by Indian DFC, we present an integer programming formulation of the dynamic problem of empty distribution and train scheduling in DFC and discuss associated modelling issues. By unifying the separate problems into a single and dynamic model, we have developed a framework for more effective rolling stock utilisation. Based on this optimization model, an interactive decision support system is proposed for better decision-making on rolling-stock allocation and train scheduling. Extensive experiments and systematic analyses for a case of Indian DFC highlight the potentialities and effectiveness of the proposed DSS for DFC operations planning and management. [ABSTRACT FROM PUBLISHER]

This article traces the development of the tram service in Magnitogorsk, one of the first socialist cities in the USSR. It first outlines the emergence of the city and the construction of the tramway in different facets: the building of tram lines, the development of tram routes and the creation of tram infrastructure. The article also discusses the influences of climate peculiarities, ideological concepts and Soviet planned economy. The focus then turns to the initial condition and development of the tram rolling stock. The main technical characteristics of the tramcars used in Soviet cities from the 1930s to the 1950s are provided. [ABSTRACT FROM AUTHOR]

Disruptions in the metro system often result in chaos in the public transport system given their substantial modal share in major metropolitan areas. Metro system disruption can be managed both within the system and by substitute bus (SB) service external to the system. Managing disruption within the metro system typically involves timetable adjustment, rolling stock scheduling, and crew rescheduling, subject to the rail system design and availability of crossovers for turnovers. SB service or bus bridging, on the other hand, is one prominent way to mitigate the negative impact of a metro disruption. In the past decade, research on this topic has grown substantially. In this paper, by conducting a comprehensive search in the Web of Science publications, we identify and review about 70 papers. According to the three aspects of metro system disruption management, we classify the literature into three groups: (i) getting prepared for metro network disruption, (ii) managing disruption within the metro system, and (iii) managing metro disruption with SB service. After summarising the state-of-the-art on this topic, we conclude by identifying gaps and future research directions, primarily on substitute bus service, for this important development effort. [ABSTRACT FROM AUTHOR]

Repoint is an alternative concept for the design of track switches developed at Loughborough University. The concept, based around a stub switch, offers several improvements over current designs. Through a novel locking arrangement, it allows parallel, multi-channel actuation and passive locking functions, providing a high degree of fault tolerance. The aim of the work presented in this paper is to evaluate the dynamic interaction forces due to the passage of rolling stock over the switch and, particularly, the area of the stub rail ends, in comparison to a conventional switch. Specific behaviour and load transfer conditions from one rail to the other at the joint are analysed, as well as long-term wear conditions of the rails. These evaluations are undertaken by means of multi-body dynamic simulations, leading to design refinement of the stub rail ends and the identification of further research and development requirements in their design. [ABSTRACT FROM AUTHOR]

The paper estimates the standard cost in Italian regional public rail passenger transport services (LPTR), depending on service characteristics. The results highlight the crucial role of: number of seats per ride, commercial speed, service size and length of rail tracks. The model also shows the positive link between investment in rolling stock and the unit cost of the service. Finally, based on the empirical evidence, we propose regulatory adjustments to accomplish policy targets regarding the fair allocation of public LPTR funds to Regions and Local Authorities and a more efficient use of (scarce) local and national public resources. [ABSTRACT FROM AUTHOR]

Efficient mobility is an essential driving force for the development of cross-border (CB) regions. The different settings and visions of neighbouring CB entities may lead to unsatisfactory transport connections across the border. This case study of a CB connection focuses on this issue and highlights, by means of a comparative analysis, how the differences in six perspectives (the economic context; urban and regional planning in Belgium and the Netherlands; the structure of the rail network; barriers in the exploitation of the railway; the current travel demand by rail; and the governance, public planning and policy context) lead to an unsatisfactory rail connection between Liège (Belgium) and Maastricht (the Netherlands). Based on the results of the analysis, we suggest reinforcing cross-mobility connections through several tools such as (i) the development of a common governance, not only at the institutional level but also at the counter level of institutional level, by including economic and social stakeholders; (ii) the development of joint technical projects in relation to the infrastructure, communication systems and the rolling stock; and (iii) the strengthening of flows between the two sides of the border, especially the home-work flows. [ABSTRACT FROM AUTHOR]

It needs some seconds for a signal, which is created from brake application, to travel from the first part of the train system (locomotive) to the end part of it (last wagon). Delay in time of all parts of the system (train) brake is seen which might deteriorate the longitudinal dynamic interaction of the long trains. For instance, this results in running of the rear cars to the front ones and hence producing large in-train forces at the buffers and couplers. Major parts of the rolling stock in railway system repair are known for relative compression and tension forces, which are applied to the whole train system and cause huge expenses for the industry. For trains with long lengths, operating in safe area is another important relation with train forces along the system. By using MATLAB simulation in this study, we investigated the length's effect on train dynamic along the system mainly for freight trains. We did our research on the trains which are currently used in Railways of Islamic Republic of Iran, RIRI. Four diverse cases were under our simulation, in each of which, trains consist of 52, 32, 20 and 12 cars, respectively. Two different forces (tension and compression) are displayed here as of the outcome of the research. Simulations show different forms of interplays in dynamics along the system. Then we compared the graphs to each other to find out detailed influences of length of the whole system (train including different number of wagons and locomotive) on dynamics of system along it while braking is applied. [ABSTRACT FROM AUTHOR]

This article describes historic load conditions in the Norwegian railway network to improve estimates of the remaining service life of bridges. Data on rolling stock, traffic and infrastructure throughout the history of the railway are presented. Axle loads, geometry, design, composition and operation of both passenger and freight trains have changed several times since the initial construction. The capacities of both rolling stock and infrastructure influence the load conditions in a railway network. Historic loads may have been more severe than modern loads for certain structural details. A probability distribution of load variables for a specific bridge cannot be obtained in the general case. Future research directions and suggestions for the use of non-probabilistic data in estimating the service life of bridges are discussed. [ABSTRACT FROM AUTHOR]

As rail operators look for efficiency improvement, a new trend towards integration of detection technologies on revenue raising rolling stock has emerged, the objective being that a saving can be made by eliminating specialised rolling stock and reducing network scheduling. An area currently attracting research attention in the Australian heavy haul segment is the detection of rail foot flaws from moving vehicles through the use of Infrared Thermography. This paper presents a modelling and simulation methodology for full train simulation using a co-simulation approach for calculating heat transfer in the rail under a number of different vehicle system dynamics cases. The excitation source for the heat transfer focuses only on wheel/rail contact mechanics. The paper will explore the problem from a Modulated Thermography perspective that uses periodic heating and observation of the heating process for flaw detection. [ABSTRACT FROM AUTHOR]

A three-dimensional dynamic model of crashed vehicles coupled with moving tracks is developed to research the dynamic behaviour of the train front end collision on tangent tracks. The three-dimensional dynamic model consists of a crashed vehicle model, moving track models, a simple wheel–rail contact model, a velocity-based coupler model and the model of energy absorption and anti-climbing devices. The vector method dealing with the nonlinear wheel–rail geometry is put forward in the paper. The developed model is applicable in the scope that central collisions occur on tangent tracks at low speeds. The examples of the vehicle impacting with a rigid wall and the train front end collision are carried out to obtain the dynamic responses of vehicles. The overriding issue is studied on the basis of the wheel rise in train collisions. The results show that the second bogie of the first colliding vehicle possesses the maximal wheel rise. The wheel rise increases with the increase of vehicles. However, the number of vehicles has tiny influence on the overriding in train collisions at low speeds. On the contrary, the impact speed has significant influence on the overriding in train collisions. The wheel rise increases rapidly if the impact speed is close to the critical speed of overriding. The large wheel rise is principally generated by the great coupler force related to the rigid impact in the axial direction. [ABSTRACT FROM AUTHOR]

This article analyzes the state of Russia’s international road transport. The main issue facing Russian shippers in this market is their low competitiveness, which has been caused by unfavorable economic conditions. It is noted that an increase in the volume of international shipments will depend on how successfully Russian enterprises use the opportunities presented by the ruble’s devaluation to build up exports of their products. [ABSTRACT FROM AUTHOR]

This article calculates the impact of three measures in order to reduce the global warming potential (GWP) and cumulative energy demand (CED) of Vienna's subway line U2. Results show that the increase of the train occupancy rate has the highest reduction impact (–30%/–30%), followed by new rolling stock (–26%/–34%), and a change in energy mix (–8%/–4%). The total reduction to be achieved with all measures combined is around –55% for GWP and CED, leading to a GWP of 91 [g] and 1.653 [MJ] per passenger kilometer traveled (PKT). With all these measures applied, the subway has lower GWP and CED than other modes of transport presented in the literature. [ABSTRACT FROM PUBLISHER]

This article presents a mixed-integer linear-programming formulation for integrating short-term maintenance planning in a network-wide railway rolling stock circulation problem. This is a key problem in railway rostering planning that requires covering a given set of services and maintenance works with a minimum amount of rolling stock units. In our formulation, a rostering solution is viewed as a minimal cost Hamiltonian cycle in a graph with service pairings, empty runs, and short-term maintenance tasks. We use a commercial MILP solver to compute efficient solutions in a short time. Experimental results on real-world scenarios from the main Italian railway company Trenitalia show that this integrated approach can reduce significantly the number of trains and empty runs when compared with the current rolling stock circulation plan. [ABSTRACT FROM PUBLISHER]

A methodology for the optimisation of a prescribed track gauge variation (gauge widening) in the switch panel of a railway turnout (switch and crossing, S&C) is presented. The aim is to reduce rail profile degradation. A holistic approach is applied, where both routes and travel directions (moves) of traffic in the switch panel are considered simultaneously. The problem is formulated as a multi-objective minimisation problem which is solved using a genetic-type optimisation algorithm which provides a set of Pareto optimal solutions. The dynamic vehicle-tumout interaction is evaluated using a multi-body simulation tool and the energy dissipation in the wheel-rail Contacts is used for the assessment of gauge parameters. Two different vehicle models are used, one freight car and one passenger train set, and a stochastic spread in wheel profile and wheel-rail friction coefficient is accounted for. It is found that gauge configurations with a large gauge-widening amplitude for the stock rail on the field side are optimal for both the through and diverging routes, while the results for the gauge side show a larger route dependence. The optimal gauge configurations are observed to be similar for both vehicle types. [ABSTRACT FROM AUTHOR]

A new method of presenting simulated wheel/rail forces and relating these to the observed wheel damage has been developed. This indicates a good correlation between the predicted forces and the regions of the wheel where damage is observed in practice. There is also a good correlation between the angle of the predicted forces and the observed cracks. The angle evidence suggests that the dominant rolling contact fatigue cracks on the field side of the wheel tread are initiated by the occasional high forces when the opposite wheel is running in flange contact on sharp curves. Cracks may then be propagated by more frequent lower forces on moderate curves. [ABSTRACT FROM AUTHOR]

By using non-contact gap sensors equipped on non-rotating parts of a bogie, a new measuring method of wheel/rail contact forces has been developed. The developed system has been verified to have sufficient durability for Continuous measurement on in-service trains and sufficient practical accuracy after various stand tests and train running tests. After a long-period of continuous measurement on a commercial subway line, some important characteristics of wheel/rail contact mechanics were found by the analysis of measured data. Numerical simulations of curving with a full vehicle model using multi-body dynamics software were carried Out, and according to the comparison with measured data, simulation results agree well with measured data in the steady-state values of derailment coefficients considering friction coefficient. [ABSTRACT FROM AUTHOR]

Rolling contact fatigue on any railway system has a significant impact on the safety and efficiency of the operation. This is especially true for heavy haul railways where higher axle loads and demands for higher throughput have, over the years, challenged the limits within the wheel/rail interface. The objective of this paper is to present a methodology to manage this stress state using a detailed wheel/rail contact stress analysis. Based on the results of recent wheel profile and rail profile surveys, a kinematic wheel/rail contact analysis is performed to identify and eliminate profiles that cause high stresses. The results show that the current hollow wear criterion is effective, but that an alternative or additional criterion based on the gauge side false flange gradient or the calculated peak contact stress values can further reduce the stress state. Within the wheel and rail profile combinations investigated, the contact stresses were largely independent of the transverse profile of the high rail. [ABSTRACT FROM AUTHOR]

Lateral force components and impacts from couplers can adversely affect wagon stability. These issues are significant in longer and heavier trains increasing the risk of wagon rollover, wheel climb, wagon body pitch, bogie pitch and wagon lift-off. Modelling of coupler angles has been added to normal longitudinal train simulation to allow comprehensive study of lateral components of coupler forces. Lateral coupler forces are then combined with centripetal inertia calculations to determine quasi-static lateral forces, quasi-static vertical forces and quasi-static bogie lateral to vertical ratio, allowing the study of stringlining, buckling and wagon rollover risks. The approach taken allows for different rolling stock lengths, overhang and coupling lengths, and allows the study of angles occurring in transitions. Wagon body and bogie pitch are also studied with enhancements added to previous modelling to allow the study of wagon lift-off. [ABSTRACT FROM AUTHOR]

According to the Belgrade Master Plan for 2021, the public transportation system for the city and its region will include three rail modes: a modernized existing tramway, regional rail, and a new light rail transit (LRT) mode. In the coming years all three rail modes should be developed simultaneously and in a coordinated manner. The introduction of LRT is to be realized in several phases, and its first line will partially follow the alignment of an existing tramway line. As the present tramway vehicles are obsolete, new rolling stock must be designed and purchased to be compatible with many of the elements of the LRT. Ways to adjust the new tramways to the LRT rolling stock represent the central topic of this paper. The basic technical and operating characteristics of the new tramway are defined with respect to their required compatibility with the LRT stock and infrastructure. [ABSTRACT FROM AUTHOR]

The need for dependable and flexible models of transit vehicle maintenance has been well established in the literature as a means for improving daily operations, capital planning and service quality. Stemming from the practical need to predict the duration of maintenance activities and active service time for buses, this paper uses the principles of duration modeling to address two important questions: what is the duration of vehicle maintenance activities and, given that a bus is in active service, how long will it take? We extend previous work by including exogenous factors directly affecting maintenance duration and active service time in fully parametric duration models and examine such activities for the transit system in Athens (Greece). Results indicate that vehicle age, kilometers travelled and repair type are amongst the most important determinants of maintenance duration. [ABSTRACT FROM AUTHOR]

The steam railway locomotive is one of the iconic machines of the Industrial period. This is refl ected in the many examples that have been preserved in museums as static exhibits, and in the replicas that have been constructed of vanished prototypes, such as the Planet and the Tornado. In addition, many historically signifi cant locomotives are now operated on heritage railways, or on heritage services, in ways that potentially affect their historic integrity. The following paper assesses the ways in which operational steam locomotives can be conserved in ways that mitigate this loss of integrity. [ABSTRACT FROM AUTHOR]

The article focuses on railway rolling stock, designed and manufactured in compliance with international regulations (UIC) and technical specifications. It states that railway stocks are characterised by the factors including high cost, average lifespan between 30-40 years, and the amortisation times. It notes that it is a key that those involved in the process and the reference institutions address their energies to the continual development of reference standards for the welding process.

The three UK rolling stock companies (ROSCOs) are a product of the privatization of the railway industry in the 1990s. As the UK approaches the 25th anniversary of the first privatization of a state-owned industry (telecommunications), this article evaluates the background and the structure of the ROSCO privatization sales. The authors show that the privatization of the UK's rolling stock industry was a significant triumph of political expediency over sound governmental financial policy. The ROSCOs have attracted relatively little attention, yet nowhere else have the flaws in the privatization process become more apparent. [ABSTRACT FROM AUTHOR]

Soil and groundwater at a rail rolling stock workshop in a metropolitan city were contaminated with heavy metals including Pb, Cu and Cd. Prior to remedial design, a variety of field and laboratory investigations were conducted to characterize hydrogeologic conditions and to examine levels and extents of the contamination. The hydrogeology of the studied site near the Han River is comprised of reclamation soil, alluvial deposit, weathered layer and soft rock. The alluvial deposit consists of sand, clay and silt, sandy gravel and its spatial distribution is very heterogeneous. Most groundwater occurs in the sandy gravel layer and groundwater within the site generally flows into two directions, north and west. Mean hydraulic gradients were 0.082-0.0129 and hydraulic conductivities of the main aquifer range between 5.42 × 10- 2 and 2.18 × 10- 6 cm/sec. Average linear velocity of groundwater was calculated as 15-24 m/year. The groundwater levels were mostly affected by atmospheric pressure change, which reflected confined characteristics of the aquifer system. High EC and low DO indicated anthropogenic contamination of the site. The Pb and Cu contamination of soil exceeding the Korean soil standards were mainly observed at locomotive inspection, rest train wash and scrap iron dump areas. Substantial contamination of groundwater with Cd was also detected at different location. [ABSTRACT FROM AUTHOR]

The article discusses Brian Hayes' report, "Trains of Thought" published in "The American Scientist" March-April 2007 issue. A "hump yard" is a sloping array of parallel tracks wherein a locomotive can take a boxcar to a certain point, rolling towards the desired track where a train is being assembled to go in its destination. Moreover, sorting algorithm can be observed in a "hump yard" that can be classified into two types which include putting all the cars for a certain train on the same track, and arranging the cars in an order to be dropped off along the route that is done using a switch engine.