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The article presents the contents of a recently discovered list detailing steam and diesel locomotives used in Poland from 1956 to 1970 on narrow-gauge railways of the State Forests. The document includes information such as the markings of individual locomotives, their manufacturers, production years, technical specifi cations, and operational history on specifi c forest railways. This information is presented in tabular format and supplemented with commentary on locomotive marking practices specifi c to forest railways, as well as a comprehensive literature review. [ABSTRACT FROM AUTHOR]

The mainline railways in Australia were initially built in three different gauges, with 'breaks-of-gauge' where passengers and goods transferred between them. This paper studies how the gauge situation affected regional development and the railway network in the 20th century. Regional breaks-of-gauge caused substantial local growth, with population and employment increasing by around 50% within a decade of them opening. However, these effects were unwound within two decades of a break-of-gauge being closed. There is little evidence of gauge segmentation causing different paces of regional development. The gauge muddle also appears to have limited the extent of the railway network. [ABSTRACT FROM AUTHOR]

The rolling stock gauge standards are generally based on the operation and technical equipment characteristics of railways in various countries. As the research and application of non-adhesive braking technology started late in our country, the domestic gauge standards are not specific on related issues, which restricts the upgrading of rolling stock and the application of new equipment. In recent years, the application demand for non-adhesive braking technology has been increasing. This article systematically compares and analyzes the current domestic and foreign rolling stock gauge standards and the problems related to non-adhesive braking, and puts forward suggestions on the revision of domestic gauge standards to provide a basis for the development of rolling stock and braking technology. The study shows that there are differences in calculation methods and lower part zone of rolling stock gauges at home and abroad. The European gauge standards fully considers the zones of components close to the track and in contact with the rails, which is an important basis for the design of non-adhesive braking devices. The external dimensions of the existing non-adhesive braking device can meet the horizontal space requirements of our country's gauge standards, but the relevant regulations need to be further clarified on the zone close to rail surface. [ABSTRACT FROM AUTHOR]

The article is an edition of the source important for the history of the development of the railway network in Poland, namely the Information on the approach railways operating in the Warsaw Governorate (Viedomosti o suŝestvuûŝih v Varšavskoj guberni pod"ezdnyh železnyh dorogah). This document is in the archival collection labeled Warsaw Governorate Government no. 1181, kept in the State Archive in Warsaw. In the Information on the approach railways operating in the Warsaw Governorate, there is data on the public and industrial narrow-gauge railways operating in the Warsaw Governorate in 1911, as well as the standard-gauge industrial sidings of the Warsaw-Vienna Railways. This document is of great historical importance due to the degree of destruction and scattering of technical archives related to the communication infrastructure in the territory of the Russian partition. It contains important, previously unknown elementary technical and operational data of these railways and sidings. [ABSTRACT FROM AUTHOR]

Railways are an indispensable component of sustainable transportation systems, but also exact a toll on wildlife. Wild Asian elephants are often killed by trains in Assam, India, where we assess temporal variations in the occurrences of elephant-train collisions (ETCs) and casualties during 1990–2018. This study also assesses spatially varying relationships between elephant-train collision (ETC) rates and elephant and train densities in the adjoining 10 km2 grid cells of 11 prioritized railroad segments using ordinary least squares (OLS) and geographically weighted regression (GWR) models. The temporal analysis indicated that ETCs spiked at certain hours and months. The adult and calf elephant casualties on the railroads were found to be two to fivefold high during the post monsoon season compared to other seasons. During the operation period of meter gauge railroads (1990–1997), the proportions of ETCs and casualties were only 15.6% and 8.7% respectively. However, these increased substantially to 84.4% and 91.3% respectively during the operation of broad gauge railroads (1998–2018). The OLS model indicated that both elephant and train densities explained 37% of the variance of ETC rate, while GWR model showed 83% of the variance of ETC rate. The local coefficient values of GWR indicated that both the predictor variables interplayed significantly and positively to determine ETC rates in the Mariani-Nakachari and Khatkhati-Dimapur railroad segments. However, the relationship between ETC rate and elephant density is significantly negative in the Habaipur-Diphu railroad, implying that the elephant population along this railroad stretch is significantly affected by railways through large scale ETCs. Hence, there is an urgent need to address long-term mitigation strategies so that elephants can be conserved by providing safe passages and survival resources along railway lines. [ABSTRACT FROM AUTHOR]

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Collusion is widely condemned for its negative effects on consumer welfare and market efficiency. In this paper, I show that collusion may also in some cases facilitate the creation of unexpected new sources of value. I bring this possibility into focus through the lens of a historical episode from the 19th century, when colluding railroads in the U.S. South converted 13,000 miles of railroad track to standard gauge over the course of two days in 1886, integrating the South into the national transportation network. Route-level freight traffic data reveal that the gauge change caused a large shift in market share from steamships to railroads, but did not affect total shipments or prices on these routes. Guided by these results, I develop a model of compatibility choice in a collusive market and argue that collusion may have enabled the gauge change to take place as it did, while also tempering the effects on prices and total shipments. This paper was accepted by Joshua Gans, business strategy. [ABSTRACT FROM AUTHOR]

I investigate the effect of assets' liquidation values on capital structure by exploiting the diversity of track gauges in nineteenth-century American railroads. The abundance of track gauges limited the redeployability of rolling stock and tracks to potential users with similar track gauge. Moreover, potential demand for both rolling stock and tracks was further diminished when many railroads went under equity receiverships. I find that the potential demand for a railroad's rolling stock and tracks were significant determinants of debt maturity and the amount of debt that was issued by railroads. The results are consistent with liquidation values models of financial contracting and capital structure. [ABSTRACT FROM AUTHOR]

Abstract Prestressed concrete sleepers are the most commonly used type of railway sleepers in ballasted railway track. They have a strong influence on track performance, track stiffness and railway safety. Reportedly in many railway lines (especially in heavy-rail networks), many prestressed concrete sleepers have failed due to rail seat abrasion (RSA). RSA is a wear deterioration of the concrete underneath the rail that results in various problems such as loss of fastening toe load, gauge variation, improper rail cant, and eventually loss of rail fastening. In addition, the RSA will directly decrease the capacity of worn concrete sleepers. However, to the best of authors' knowledge, there were very few studies that quantitatively examined the effects of RSA on the structural capacity of the prestressed concrete sleepers. In this paper, a numerical study is executed to evaluate the load-carrying capacity of a prestressed concrete sleeper using LS-DYNA. The nonlinear model was validated firstly based on both theoretical analyses and experimental results in accordance with Australian Standard. Using the validated finite element model, the influences of different wear depth of RSA are investigated; and different compression strength and tensile strength of concrete and the prestress losses are highlighted. The outcomes of this study lead to better insight into the influences of RSA more clearly and improve track maintenance and inspection criteria. Highlights • Nonlinear FEM for railway sleeper failures is developed. • Three dimensional finite element models have been established using material nonlinearities. • Experimental and design data have been used to rigorously validate the model results. • Failure modes of sleepers with abrasion are comprehensively identified. • Structural capacity of the sleepers depends largely on the abrasion types and severity. • The new insight into failure mechanisms will help track engineers to better monitor and maintain sleepers in ballasted track environments. [ABSTRACT FROM AUTHOR]

Abstract As the number of concrete railway sleepers has steadily grown in North America, the importance of understanding the performance and failure of these components has also increased. Concrete sleepers typically perform better than timber sleepers to maintain track geometry and have a longer expected service life. Nevertheless, there have been derailments that were caused by excessive increase of track gauge due to deteriorated concrete sleepers and fastening systems. As ballast support conditions are closely related to sleeper performance, there is a need to fully understand the behavior of poorly supported sleepers. To quantify the influence of support conditions on sleeper deflection and gauge widening, laboratory experiments were performed. Using a static structural loading frame, new and center-cracked concrete sleepers were subjected to different support conditions, engineered using rubber pads. Simulated conditions included center bound sleepers, newly tamped track, and track under high impact loads. This paper presents a correlation between ballast support conditions and their effect on concrete sleeper health and track gauge. Using statistical tools to analyze the experimental results, it is shown that there is no significant difference between new sleepers and lightly center-cracked sleepers. Even extreme deterioration at the sleeper center has little influence on the gauge widening effect due to sleeper bending. Moreover, the gauge widening effect due to pure concrete sleeper bending seemed to be minimal, but not insignificant when compared to the amount of track gauge increase due to other track infrastructure conditions. Therefore, railway accidents where damaged concrete sleepers fail to restrain track gauge are more likely to be related to the rail seat, fastening system, or other production problems rather than center cracking. Highlights • Railroad track gauge increase due to concrete sleeper bending is quantified. • Various support conditions representing real railroad track are considered. • Light and severely center-cracked sleepers are analyzed. • Bending of center-cracked concrete sleepers does not seem to be a safety issue for railroad operations. [ABSTRACT FROM AUTHOR]

One of the technical possibilities to solve a gauge crossing is to install a dual gauge. This solution has several advantages and disadvantages discussed in this paper. Lack of experience of maintenance and lack of standards for the design of dual track are among the most important disadvantages. The wheel and rail interface on track curves is more difficult than in straight sections. Therefore, the subject of the present article is a geometrical parameter of dual gauge track, i.e., the rail superelevation, which has an impact on the wheel-rail interaction at curves and influences the value of uncompensated acceleration, occurring when a train passes a curve, and, consequently, the intensity of rail wear. The objective of the present article is to analyse the features of dual gauge track and the superelevation calculation methodology considered, to present the approach to rational calculation of superelevation for dual gauge track of Šeštokai-Mockava (Lithuania-Poland) using several calculation versions as well as to make recommendations for the calculation of superelevation. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method for finding the optimal route for a specific train from a station to another one in the Spanish railway network (or any railway network involving different incompatible features like gauges, electrification and signaling systems). The complexity of the Spanish railway infrastructure makes it difficult to give an estimation of the fastest route of a train from a given station to another. Indeed, very unintuitive situations may happen. The problem of finding fastest routes is typically modeled by a graph where nodes represent stations and edges represent railway sections. However, this approach is not suitable for the Spanish railway network. In order to solve the problem of calculating the fastest routes, we will propose here a novel approach based on modeling the railway network through a different graph whose nodes represent railway sections. [ABSTRACT FROM AUTHOR]

Nowadays, wayside measurement systems of wheel-rail contact forces have acquired great relevance for the monitoring of rolling stock, especially for freight trains. Thanks to these solutions, infrastructure managers can check and monitor the status of rolling stock and, when necessary, impose corrective actions for the railway companies. On the other hand, the evaluation of contact forces is part of the rolling stock authorisation process [1] and a mainstone for the study of the running stability. The data provided by these measurements could give useful information to correlate the wear of the track with the frequency of applied loads, helping in the development of a better maintenance strategy of railway networks [2]. In this paper, the monitoring of vertical forces is based on the SMCV (Vertical Loads Monitoring System) method, where shear strains of the rail web are measured with a simple combination of four electrical strain gauges, placed on both sides of the rail web along each span. The research has identified self-diagnosis methods for the SMCV system to ensure the reliability and the quality of the measurements and to extend the knowledge of the system. The recorded signals have been processed and converted into easily interpretable physical quantities by means of MATLAB® algorithm. [ABSTRACT FROM AUTHOR]

This paper uses Data Envelopment Analysis to assess the efficiency of Brazilian rail concessionaires between 2010 and 2014, when new competitive regulations were introduced. In a second stage, a Bootstrap Truncated Regression was used to test the significance of exogenous variables on concessionaire performance: main type of cargo, track gauge, railway operation type (shared infrastructure or monopoly), in order to address an important gap in the literature. Secondary data came from the National Land Transport Agency (ANTT). The findings have significance for broad-gauge track commodities transport, while shared-infrastructure operations had no significance on efficiency, despite regulator incentives. Well directed regulations must encourage concessionaires to increase efficiency, particularly through incentives for agricultural and mineral commodities carried on the broad-gauge track characteristic of North and Center-West Brazil. Public policies designed to boost cluster efficiency are presented, addressing options such as upsizing, downsizing and resizing inputs, restructuring, best management practices and infrastructure upgrades. [ABSTRACT FROM AUTHOR]

This paper describes the construction of a stochastic model of urban railway track geometry irregularities, based on experimental data. The considered irregularities are track gauge, superelevation, horizontal and vertical curvatures. They are modelled as random fields whose statistical properties are extracted from a large set of on-track measurements of the geometry of an urban railway network. About 300–1000 terms are used in the Karhunen–Loève/Polynomial Chaos expansions to represent the random fields with appropriate accuracy. The construction of the random fields is then validated by comparing on-track measurements of the contact forces and numerical dynamics simulations for different operational conditions (train velocity and car load) and horizontal layouts (alignment, curve). The dynamics simulations are performed both with and without randomly generated geometrical irregularities for the track. The power spectrum densities obtained from the dynamics simulations with the model of geometrical irregularities compare extremely well with those obtained from the experimental contact forces. Without irregularities, the spectrum is 10–50 dB too low. [ABSTRACT FROM PUBLISHER]

A methodology to predict gauge corner and flange root degradation in terms of rolling contact fatigue (RCF) and wear from measured rail, wheel and track geometries by so-called meta-models is presented. The methodology sets out from a parametrisation of the gauge corner and the flange root geometries. Then statistics of measured rail and wheel profiles are employed in a experimental design methodology to create scenarios, which are employed in multibody simulations from where degradation indices are evaluated. Finally, classification and regression analysis is used to derive decision boundaries and meta-models. These predict whether contact will occur at the gauge corner and (when this is the case) quantify RCF and wear impacts. The derived meta-models are used to rank measured profiles based on how detrimental they are. Robustness is assessed through comparisons between two vehicle types. The ability to rank measured profiles without the need for computationally expensive simulations (including the need for additional presumptions that such simulations require) makes the study valuable e.g. for maintenance planning. [ABSTRACT FROM AUTHOR]

The concept of managing and adjustment of friction between the wheel and rail has a long history within the operation of railways systems. In the past, adjustment/management has been limited to gauge face lubrication and the use of sanding equipment. The introduction of the top of rail (TOR) friction modifier (FM) over the last 20 years now allows for the modification of the friction at the top of rail–wheel tread interface. This paper focusses on the concept of TOR friction adjustment. Recent developments have led to a new generation of products, defined here as, TOR lubricants (oil and/or grease-based) and hybrid materials (oil/water mixtures), which are non-drying or slow drying. Definitions and functional difference are detailed and contrasted with that of the water-based drying FM. The water-based TOR-FM once applied rapidly dries, mixes with the existing third-body layer, and allows for the accommodation of shear displacement. TOR lubricants and hybrid materials rely on mixed boundary layer lubrication, contrary to application of the water-based TOR-FM. It has been shown that the adhesion level is highly influenced by the lubricant application rates. The risks and benefits (lateral force reduction, corrugation mitigation, and impact on energy consumption and influence on rolling contact fatigue) are discussed for all product classifications. However, a lack of data exists for the TOR lubricants especially in the area of rolling contact fatigue where laboratory studies have identified the possibility of crack interaction. Whilst it can be seen that TOR lubricants have the ability to provide similar benefits to that of a water-based FM, they exhibit a strong dependency on the application rate which may lend itself to adhesion and RCF issues. Further work is recommended in this area. [ABSTRACT FROM AUTHOR]

The structural assessment of old metallic bridges is a challenge for civil engineers. This is mainly due to difficulties in identifying material properties and vehicle characteristics. A great number of these bridges were built with materials that are no longer used in modern structures and are presently subjected to loads very different from the ones considered in the design. In this context, structural monitoring can be an important tool to characterize the structural behavior and to support the safety assessment. In this paper, the steps taken to implement a Bridge-Weigh-in-Motion algorithm for traffic characterization in a railway bridge are presented. For that purpose, a long term monitoring system based on strain gauges was installed in the Portuguese Trezói Bridge. The measurements from a period of approximately two years were used to obtain axle loads, axles spacing and velocities of the trains that crossed the bridge during this period, enabling the accurate characterization of the real traffic conditions. This was achieved applying a method for traffic characterization based on the research developed by Moses (1979) and also based on the recent research developed by Liljencrantz et al. (2007) and Quilligan (2003), which was enhanced by an optimization algorithm implemented to minimize the error of the simulated response when compared to the measured response of the structure, thus allowing the estimation axle loads, axle spacing and speed. [ABSTRACT FROM AUTHOR]

Dispatchers often set noncrossing block sections (NCBSs) for railway out-of-gauge train (OGT) running on double-track railway line for safety reasons. In this paper, we will investigate the best location, length, and number of noncrossing block sections to reduce railway capacity loss due to the operation of OGTs. Firstly, yielding, overtaking, stopping, starting, and other operation rules for OGTs running on double-track railway line were designed, and a simulation model based on cellular automata was further put forward. Then, an assessment model for double-track railway line capacity loss due to the operation of OGTs was set up. Some simulation experiments and the comparisons of these results were further given to achieve the optimal setting of NCBS for OGTs running on double-track railway line. In the case of NCBSs number minus one, capacity loss caused by the operation of OGTs can be reduced up to 15.2% in the upstream direction and 6.3% in the downstream direction. Also, the NCBSs should lie at the nearest block sections (BSs) to depot stations and the NCBSs lengths should be as less as possible. [ABSTRACT FROM AUTHOR]

There is a growing interest in recent years of many African countries to revamp their neglected railways in order to promote regional trade and transportation integration. Investors are faced with problems of railway track gauge conversions to promote railway inter operability . The objective of the work documented here was to numerically evaluate the impact of track gauge conversions on traffic load induced permanent deformation (PD) of low embankment on soft sub-grade. A method to predict the traffic load induced settlement of low embankment on soft sub-grade is proposed. Using the user-defined material subroutines (UMAT) in ABAQUS, a 2-D finite element (FE) model was formulated. These models are converted into a numerical formulation for implementation in FE analysis and the traffic load induced dynamic stress in the sub grade are calculated by using the multi-layer elastic theory. Then the plastic vertical strain in the sub-grade is calculated by an empirical equation, whose constants are related to the physical and mechanical properties of the sub-grade soil. The method was applied to analyze a 700m long section of a low embankment on the soft black cotton soil of Nakuru plains in Kenya. Corresponding results showed that the application of traffic loads on alternate rail tracks due to gauge conversions have a significant effect on the permanent deformation of the sub grade soil. The depth significantly influenced by traffic loading was found to be close to 6 m below the base of the embankment. The analysis also shows that increasing the thickness and stiffness of the sub grade is a very effective way of reducing the traffic load induced permanent deformation of soft sub grade soil. The proposed method can be used for settlement analysis on low embankments as well as a useful tool for making decisions on railway track gauge conversions. [ABSTRACT FROM AUTHOR]

Sleepers are the primary structural components that provide the necessary gauge width and the structural stability to the ballasted railway track. High performance prestressed concrete sleepers of high-speed railways have strict design and production requirements to provide a safe, serviceable and a reliable railway superstructure. The production dimensions of a contemporary prestressed high performance concrete sleeper are within low tolerance values on the scale of a millimeter that is uncommon for ordinary structural concrete elements. Railways are within climatic conditions that could become effective in the dimensional stability of their sleepers. Within regions of low humidity levels, in addition to the elastic shortening of the prestressed sleepers, the effects of concrete creep and shrinkage could lead to total contraction values in excess of the allowed tolerances for the shoulder width of the sleepers. Therefore the dimensional design of a high performance prestressed concrete sleeper must include the effects of time dependent dimensional changes. This paper presents the possibility of falling out of dimensional tolerance for prestressed high performance sleepers and ways to mitigate those possibilities for railways in arid climatic conditions or within climatic zones undergoing a climate change. [ABSTRACT FROM AUTHOR]

In the article a curvature analysis of a three axial bogie of the locomotive type JŽ 461 was implemented. The feature of that type of locomotive is that it has a long distance between first and middle axis, which means the distance between the middle and last axis is long too. That feature leads to greater lateral forces during curve negotiation. As a result, the widening of the railway gauge in small radius curvature may appear. The article points that Infrastructure Manager must consider the specialties of vehicle performance and rail type when defines track gauge's curvature. [ABSTRACT FROM AUTHOR]

Analysing track geometry defects is critical for safe and effective railway transportation. Rectifying the appropriate number, types and combinations of geo-defects can effectively reduce the probability of derailments. In this paper, we propose an analytical framework to assist geo-defect rectification decision making. Our major contributions lie in formulating and integrating the following three data-driven models: (1) A track deterioration model to capture the degradation process of different types of geo-defects; (2) A survival model to assess the dynamic derailment risk as a function of track defect and traffic conditions; (3) An optimization model to plan track rectification activities with two different objectives: a cost-based formulation (CF) and a risk-based formulation (RF). We apply these approaches to solve the optimal rectification planning problem for a real-world railway application. We show that the proposed formulations are efficient as well as effective, as compared with existing strategies currently in practice. [ABSTRACT FROM AUTHOR]

The SUW 2000 railway vehicle wheel set with an automatic gauge change system is especially exposed to fatigue wear due to the specific working conditions. Taking into consideration the role which a wheel set has in both vehicle handling on a track and providing safety of railway traffic, the wheel set damage is impermissible. It also applies to the sleeve–axle rotational connection. This article presents research into both finding new and low-cost materials for a slide sleeve in the wheel hub node and looking for cheaper technologies for improving the surface layer of the wheel set under-hub which would eliminate fretting wear. The research was conducted on a simplified physical model of a real connection between a wheel and an axle. The results of the conducted wear tests show that fretting wear can be effectively limited by applying a metallic layer in the form of molybdenum coating. Grease with the addition of molybdenum disulphide can also protect the co-operating surfaces against fretting wear. It also allows for sustaining proper working conditions of frictional pair elements. This solution, however, is onerous due to the limited maintainability of the connection node. The studies carried out show that there is a full possibility of using this solution in real exploitation. [ABSTRACT FROM AUTHOR]

The railway rolling noise prediction software (RRNPS) is a simulation model for predicting the sound pressure levels during a train passage due to wheel/rail roughness, based on vibration dynamics, contact mechanics and sound radiation modules. Some field validation has been done under European and Australian conditions. Comparisons between simulations and measurements have shown that this software model gives reliable predictions in terms of overall A-weighted sound pressure level and noise spectrum. In this paper, based on a typical railway rolling noise situation in Australia (a series of field measurements were taken at a narrow track gauge testing site), a sensitivity analysis of the RRNPS was carried out to investigate the effect of train speed, normal load, sleeper spacing, rail pad stiffness, track gauge and rail cross receptance factor on railway rolling noise. The results provide some insight into model-based methods to control and mitigate railway noise at its source. [ABSTRACT FROM AUTHOR]

On the LHS line (Broad-gauge Metallurgical Line), far out West of the railway line with a gauge of 1520 mm, heavy goods trains for a gross weight 5500 tons and a length of 850 m are operated. The article presents the results of a simulation study of the forces that occur in the automatic coupling device of SA-3 type of Russian production train consisting of 60 coal wagons of Russian construction of gross mass 91 tons each. The train moves on the 1520 mm gauge tracks curve S type (the radius of curvature of curves 300 m). Simulation studies were conducted using the Train Module of program to dynamic study multi-elements systems of Universal Mechanism UM 6.0. [ABSTRACT FROM AUTHOR]

The article presents a study which examines how several technological challenges were overcome by the tram-train railway project, which is under ownership and management of the Administrador de Infraestructuras Ferroviarias (Adif), in Cádiz Bay, Spain. These challenges include the track gauge, the passenger access and the bogies. The infrastructure, rolling stock, operation and future expansion plans for the project is also discussed.

Highlights: [•] We propose a system for the wheel–rail contact forces measurements. [•] Measurement principle is based on the rail strains measurement using strain gauges. [•] In addition the system provides identification of the contact point position. [•] The system is intended for research of dynamic behaviour of the railway vehicles. [•] System decouples force components using independent component analysis. [ABSTRACT FROM AUTHOR]

Lateral oscillation of railway vehicles is a major problem for narrow gauge railways or metric because reduced diameter bogie wheels. This problem can be reduced by changing the Prud'homme limit on vehicles and improving resistance tread lateral, being able to use the checkrails. Running with lateral oscillations road of the railway vehicles passenger and freight is a known problem for standard gauge railways. The lateral movement represents a particular problem which causes passengers discomfort and in major cases, the operating speed must be reduced. Whilst the railways and trains may suffer because of this. A possibility to resolve these problems should as reducing the Prud'homme limit, which defines the permissible lateral load, repeated exerted on the rail. This formula was used for vehicles and standard gauge railways, but many companies and suppliers of rolling stock have assumed that can be applied on narrow gauge lines. On the basis of existing information, without being made field tests or computer simulations, Prud'homme limit can be modified to standard gauge rail networks, but to verify the load lateral of this type of gauge must be made more investigations. Inevitably have emerged more simplistic assumptions, but is unlikely to significantly alter the conclusions. [ABSTRACT FROM AUTHOR]

The Spanish railway network has two different track gauges, two electrification systems, and four families of signaling systems--and the rolling stock includes hybrid trains. The new, extended package presented here finds the timings and best route for any piece of rolling stock and computes its consumption, emissions, and exploitation costs. [ABSTRACT FROM PUBLISHER]

Wheel/rail contact is critical to the successful operation of a railway network. Contact occurs at the wheel tread/rail head and wheel flange/rail gauge corner. Contact conditions are more severe in the latter, which occurs mainly at curves. The contact is small and supports large loads; therefore, high contact stresses are generated. These, combined with the slip in the contact, are primarily responsible for driving the processes that lead to wheel and rail damage, whether by deformation, wear or a fatigue process. Multi-body dynamics software is useful for predicting the wheel/rail contact characteristics; however, there is a shortage of experimental tools available. In this study, the feasibility of an approach based on an ultrasonic sensor mounted on the wheel is investigated. The sensor emits an ultrasonic pulse which is designed to impinge on the wheel flange. If there is no contact the pulse is fully reflected back at the flange and picked up by the same sensor. If flange contact takes place, a proportion of the pulse amplitude will be transmitted into the rail. The signal reflected back to the sensor is therefore reduced. The amount by which this signal reduces indicates how much flange contact has occurred. This work had two aspects. First, a standard ultrasonic ray-tracing software package was used to establish what it is possible to measure with sensors mounted in the wheel and to determine the best location and orientation. The second aspect was an experimental study to determine whether such measurements are feasible. Test specimens were cut from sections of wheel and rail, and a 2 MHz ultrasonic contact transducer was bonded onto the wheel in a position best suited to detect the flange contact. The specimens were pressed together in a bi-axial loading frame to generate differing degrees of rail head and flange contact. The reflected signal was monitored as the normal and lateral loads were varied. It proved possible not only to detect the onset of flanging, but also to record a signal that varied monotonically with both normal and lateral applied load. A map of reflected ultrasound against the applied loading is presented. The technology, while not currently suitable for full field implementation could be very useful in laboratory studies on, for example, a full-scale wheel/rail rig. [ABSTRACT FROM PUBLISHER]

This research aims to gauge the economic impact of the measures set out in the Strategic Infrastructure and Transport Plan, 2005–2020, as implemented by the Spanish government, on regional development. Contributing to regional development, this plan extends high capacity road networks and high performance rail networks in Spain between 2005 and 2020. To evaluate the plan, this research relies on an innovative technique based on panel data and accessibility indicators, which can quantify the plan's economic impact on regional development. Findings from the study provide a valuable tool for economic, geographic, and territorial assessments of policies implemented in the field of transport and infrastructure, whilst also pointing to guidelines for the design and development of further proposals and actions. [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]

Highly localized stresses generated at the gauge corner of the outer rail cause fatigue cracking. The longitudinal bending stresses in the rail underhead radius position are of special interest, as tension spikes have been identified at this location during in-track measurements under high axle load conditions. The tension spike is a result of vertical and lateral head bending on the web. This effect is highly localized and is additional to the stresses generated due to vertical and lateral bending of the whole rail profile (the so-called global bending). This study examined contact and bending stresses by modelling the rail on a discrete foundation using finite elements and by considering the loading to be a fully slipping elliptical Hertzian contact patch. The analysis revealed that the tensile longitudinal stress was highly dependent on several service conditions: the contact patch offset from the rail centreline, the ratio of lateral (L) to vertical (V) loads, the direction of lateral traction, foundation stiffness and seasonal temperature variations. The tension spike increases, and the depth below the contact surface at which the stresses become tensile reduces, as the contact patch offset and/or the L/V ratio increases. Both these enhance the tendency for rolling contact fatigue cracks to turn downwards and become transverse defects. This is because an increase in tensile bending stresses together with both residual and thermally induced stresses can facilitate cracks to turn perpendicular to the tensile stresses once they reach a critical length. Shear traction towards the gauge corner was found to be the most damaging phenomenon. [ABSTRACT FROM AUTHOR]

In the 1970s, a rolling contact fatigue defect that was christened a squat was identified on the British railway network, primarily at first on the West Coast Main Line. Two productive decades of international research on squats followed, which later contributed to a rapid understanding of gauge corner cracking, which differs in detail but is similar in many important respects to a classic squat. In the last 10–15 years, a rail defect that is superficially similar to the classic squat has appeared on several railways. This has been investigated in some detail, initially in Australia and more recently also in Europe as part of the Innotrack project. These investigations have both assumed that the investigated defect is a classic squat. This paper reviews research on the squat and on its younger cousin. It forms the basis for a companion paper that presents original observations from track and detailed metallurgical examinations of specimens of the more recent squat-type defect. The review in this paper is used in the companion paper to identify features of the two types of defects that are similar and those that are significantly different. [ABSTRACT FROM AUTHOR]

Maintaining track clearances in ballasted railway tracks are a critical issue for the safety and operational performance of the railway environment. In general, railway standards aredefined with respect to the minimum gauge clearance allowed between the dynamic swept envelope of the train vehicles and the fixed structure for a given vehicle speed. Absolute clearance of a line is categorized based on the clearance level, for example, in the UK, it is defined in terms of normal, reduced, or special reduced clearance. In special reduced clearance, the level of track fixity is defined as high fixity, medium fixity, and low fixity. In high track fixity, a concrete-slab track solution must be adopted; in medium track fixity, some form of ballast stabilization and/or reinforcement can be used. The principal requirement is that using a standard methodology, the clearances should always be greater than zero; the clearance representing the margin for unknown events. In this article, an in situ three-dimensional (3D) polyurethane ballast reinforcement technique is used to provide a very robust level of track fixity. The performance of the reinforcement technique is shown through experimental tests using a 200 ton capacity cyclic compression machine. The experimental tests are used to show the performance of the technique for applications like railway tunnels and station platforms where clearances issues are paramount. The base and shoulder GeoComposite experimental tests are performed with the initial ballast poorly compacted thus representing a worse case on-site scenario. Based on the experimental results, a new track fixity category is proposed termed virtual high fixity. A case study showing the impact and site application of the 3D polyurethane reinforcement research to Grovehill Tunnel UK is presented and reference is also made to another reinforced clearance issue site at Hoxton Station UK. [ABSTRACT FROM AUTHOR]

Lateral forces between wheels and rails must be reduced in order that rolling stock runs safely and smoothly on curved tracks. The excessive lateral force will cause not only derailment of rolling stock but also destruction of tracks, rail corrugation, track irregularity, squeal noise and wear. It is important to reduce lateral force of wheels in curves, so new wheel-tread profiles and steerable bogie structures have been developed up to now, however, they cannot solve various problems in curving perfectly. In this article, the authors propose three methods for improvement of running performance on curves by using existing types of wheels and rails, and analyse the effects of three methods by numerical simulation. According to analytical results, the authors conclude that ‘expansion of gauge widening’, and ‘larger rail inclination angle of inner rail installation’ or ‘asymmetrically inclined grinding of inner rail head’ can get sufficient rolling radius difference, and are effective for improvement of running performance on curved tracks. [ABSTRACT FROM AUTHOR]

Measurement system analysis is a vital component of many continuous improvement initiatives. In the manufacturing industry, variation in a measurement system is a key characteristic to be assessed and improved upon. Measurement systems are commonly evaluated by performing a gauge repeatability and reproducibility (gauge R&R) study, which analyses any variations between measurements by a gauge (repeatability) and between results obtained by different appraisers (reproducibility). To determine the preferred method for gauge R&R analysis; average and range, and two-way analysis of variance were applied to data taken from four real case studies from the automotive industry (a stabilizer clamp bracket, a coated steel sheet, a steel sheet body panel, and a brake disc). Possible differences in gauge R&R characteristics were compared, and residual diagnosis was used to discern violations in two-way ANOVA. To develop a robust road map for gauge R&R analysis, interactions between gauge R&R parameters, residual diagnosis, and number of distinct categories were analysed. [ABSTRACT FROM AUTHOR]

Abstract: In order to know the relationship between the occurrence of flaking leading to the rail breakage and wear of the rail, on-site investigations and analysis of the broken rail were carried out. As a result, it was found out that the occurrence rate of the flaking damage was high at gauge corner side of high rail in moderate curves with radius from 800m to 1800m. It was also found that the rail wear in the section where lubrication was applied was about a half of that in the section without lubrication. Moreover, it was found that flaking damage was generated on the running surface or in the close vicinity of the surface of rail head under the condition of repeated loading of shear and tangential forces caused by the rolling contact with wheels. It could be assumed that the balance between the wear and the accumulation of micro-strain or fatigue was a key to occur the flaking damage. [Copyright &y& Elsevier]

Abstract: Earlier in an ongoing research project, we identified wear transitions, mechanisms, and regimes by experimentally testing the sliding part of a wheel–rail contact. Going further, the present study investigates the effects of elevated contact temperature and severe contact conditions corresponding to those of a wheel flange–gauge corner contact. Prior studies discussed wear in terms of contact pressure, amount and type of lubricant, sliding velocity, generated airborne particles, wear depth, coefficient of friction, and topographical measurements. This study shifts the focus to contact temperature, elemental and morphological analysis of the airborne particles, and surface-layer microstructure of test specimens by using several analytical techniques (i.e., SEM, FIB, ESCA, and energy mapping). As contact severity increased, the bulk temperature of the contacting bodies increased rapidly; this can be related to elevated contact temperature by judging the size and shape of the ultrafine particles generated. After test runs, the contacting bodies were analysed, revealing microstructural surface layer changes and differences in the amount of oxide formed in the immediate surface. When the sliding part of the wheel–rail contact under severe contact conditions is experimentally simulated using pin-on-disc methodology, the discussion shifts from analyzing steady-state measurements, such as average wear rate, to more transient behaviours during running-in. Wear transitions occurring during running-in are decisive for the outcome of the rest of the test run, according to the present results. [Copyright &y& Elsevier]

Abstract: The experimental research on the wears of wheel and rail has been carried out using a large rolling-sliding contact test machine with the actual profiles of wheel and rail. Primarily, the effects of axle load, the angle of attack, rail hardness and lubrication on wear behaviors of wheel flange and rail gauge corner have been particularly focused in research. Based on those experimental results, the Archard wear coefficients of Japanese track were calculated under various conditions. A wear prediction model of rail profile taking into consideration contact stress, slip ratio at contact patch and material hardness was established based on the experimental results and the wheel–rail contact analyses. The prediction results were compared with the measured values of the actual rail and the effectiveness of wear prediction methodology was verified for the actual railway system. [Copyright &y& Elsevier]

A methodology for simulating wear, rolling contact fatigue, and plastic deformation for a mixed traffic situation in switches and crossings (S&C) has been developed. The methodology includes simulation of dynamic vehicle—track interaction considering stochastic variations in input data, simulation of wheel—rail contacts accounting for non-linear material properties and plasticity, and simulation of wear and plastic deformation in the rail during the life of the S&C component. To find means of improving the switch panel design, the geometry of a designed track gauge variation in the switch panel has been represented in a parametric way. For traffic in the facing and trailing moves of the through route, an optimum solution was identified and then validated by evaluating a wide set of simulation cases (using different wheel profiles). The optimum design includes a 12 mm maximum gauge widening. Several crossing geometries were investigated to find an optimal geometric design for the crossing nose and wing rails. The MaKüDe design showed the best performance for moderately worn wheel profiles in both running directions (facing and trailing moves). In connection with reduced support stiffness (e.g. elastic rail pads), this crossing design is predicted to lead to a significant reduction of impact loads and consequently provide a high potential of life-cycle cost reduction. [ABSTRACT FROM AUTHOR]

The problem with Model 18-100 three-piece bogies operated in Russia is that the flange wear rate is much higher than that for the tread. Scientists who studied the problem proposed various reasons for this, such as adopting a 1520 mm gauge instead of 1524 mm in the 1960s, installation of roller bearings instead of friction ones, either increased or insufficient yaw resistance torque of the bogie, geometric changes due to wear in operation and many others. The paper studies the input of different factors into flange wear by simulation and measurements in operation and proposes a statistical approach to determine the total input. [ABSTRACT FROM AUTHOR]

The equivalent conicity is widely used to characterise the wheel/rail contact geometry; however, it does not consider the contact nonlinearity. There is a need for an improved but still simple description, which accounts for the most important effect of the contact nonlinearity on the running dynamics of railway vehicles. This article demonstrates the influence of the contact nonlinearities on the behaviour of railway vehicles at the stability limit and presents a description of wheel/rail contact geometry using two parameters. The proposed characteristic parameters are compared with the examples of wheelset/track pairs and the correlation between the proposed parameters and the vehicle behaviour presented. [ABSTRACT FROM AUTHOR]

The influence of rail cant on the overall geometry conditions of railway tracks is assessed both theoretically and experimentally in this study. Extensive data obtained from a light railway line are used for experimental investigations. Modelling of rail-wheel contact using the ADAMS/Rail program is undertaken for theoretical investigations. The need to incorporate rail cant into the development of the track geometry indices is identified, and a method of performing this is proposed. Using this approach, a new track index is defined, for which the main geometry parameters, including alignment, profile, track twist, track gauge, and rail cant (rail twist), are considered. For the development of the new track index, these parameters are combined, assigning justified coefficients to each geometry parameter according to its contribution to the overall conditions of the track. The research methodology and the results are discussed. A practical use of the new index is presented to indicate its capability and applicability. [ABSTRACT FROM AUTHOR]

In this paper we consider the location of Stops along the edges of an already existing public transportation network. This can be the introduction of bus stops along some given bus routes, or of railway stations along the tracks in a railway network. The positive effect of new Stops is given by the better access of the potential customers to public transportation, while the travel time increases due to the additional Stopping activities of the trains. The latter leads to a negative effect for the customers. The goal is to cover all given demand points with a minimal amount of additional traveling time, where covering may be defined with respect to an arbitrary norm or gauge. This problem is NP-hard, even in the special case of Euclidean distances. In this paper, we derive a finite candidate set leading to a discrete set covering problem. Moreover, we identify network structures in which the coefficient matrix of the resulting set covering problem is totally unimodular, such that the problem can be solved efficiently in this case. Extensions of the problem are also discussed. [ABSTRACT FROM AUTHOR]

Two types of track gauges are currently in use in the Spanish railway network: the traditional 'iberian' wide gauge of 1668mm used in the conventional network and the international 1435mm gauge used for the high-speed lines. The dual-gauge track, in which a third rail is added to the classical two-rail layout, has recently been proposed for the design of new lines. This solution implies a substantial modification of the classical ballasted track structure and thus requires an analysis of mechanical phenomena occurring on the rail-sleeper grid of the track. In particular, this study focused on lateral track buckling, produced by the axial compression stresses on the rails induced by increases in temperature. Whenever the axial compression force exceeds a critical threshold, the track could become unstable as significant lateral deflections may appear thus leading to unacceptable riding safety levels. In this case, the addition of the third rail increases the steel section and therefore the axial compression, which may lead to track instability. This study assessed this phenomenon in detail by means of a three-dimensional, nonlinear, numerical finite element model, based upon the latest reports of the European Railway Research Institute. Several conclusions have been derived from this study as regards the increasing risk of instability in a dual-gauge track. [ABSTRACT FROM AUTHOR]

One main characteristic of Talgo trains from the very beginning in 1942 is the use of single-axle running gears with independently rotating wheels and non-active steering systems. This feature has allowed the use of other technical solutions that are usually more difficult to implement in conventional rolling stock, such as the lower coach floor, the automatic variable gauge system or the natural tilting technology. The present paper deals with the singularities in the modelling of the dynamic behaviour of Talgo trains, due to their particular characteristics. [ABSTRACT FROM AUTHOR]