Railway Network Research Articles

Feasibility of establishing an integrated railway-based containerised cargo transport network between the Port of Colombo and free trade zones in Sri Lanka

A large percentage of Sri Lanka's exports and imports are generated by the manufacturing sector and originates from facilities dispersed throughout Export Processing Zones (EPZs) around the country. An efficient hinterland transport network is required between the Port of Colombo and these EPZs. However, road trucks are used as the dominant transport mode for moving containerised cargo to/from Colombo Port. This study proposes a dry port-based containerised import/export cargo transportation method using a railway network to connect the Port of Colombo and the EPZs under several alternative network configurations. This study conducts a questionnaire survey with 40 experts to identify issues with the current road-based container transport network and ascertain the benefits of proposed railway-based networks in Sri Lanka. A majority of respondents highlight the benefits of the proposed network from multiple perspectives along with several drawbacks with the current road-based network. Initially, the feasibility of two alternative dry port locations in Orugodawatta and Kerawalapitiya are analysed. A mathematical model is developed to analyse the feasibility of the proposed alternative networks. Finally, the optimum dry port location is selected as Aluthwaththa using a simulation-based Greenfield analysis approach. Results highlight the advantages of proposed networks under several scenarios. The study demonstrates a systematic approach to decision-making by optimising the local cargo handling process, where, Sri Lankan inland logistic operations will become more efficient, with total transport costs, environmental pollution, and transportation time decreasing significantly.

An Integrated Optimization Method of High-Speed Railway Rescheduling Problem at the Network Level

For high-speed railway operations at the network level, unforeseen events that lead to operation interruptions are inevitable, which should be handled within a short period of time to reduce the influence of the events as much as possible. This paper introduces an integrated optimization method to deal with rescheduling problems at the railway network level under emergencies, rescheduling the train timetable, and utilizing the train sets. train set A three-objective optimization model is proposed with the aim of minimizing additional operation costs, total delay, and the number of transfer passengers. Then, an algorithm based on NSGA-III is proposed to solve the model. Computational experiments on real data are conducted to show the adaptability of the model and algorithm. The average optimization rate of the three objectives is 12.12%, 14.12%, and 10.57%, indicating the effectiveness of the method. Moreover, more experiments on a railway network in China are being conducted to analyze which section and which time have the greatest impact on the railway network when emergencies occur. According to the experiment, the bottleneck section is section 15, and the bottleneck time is 11:00 am. In addition, the importance of all the depots is discussed, and depot II is selected as the most important depot.

Spatio-Temporal Evolution of Urban Expansion along Suburban Railway Lines in Megacities Based on Multi-Source Data: A Case Study of Beijing, China

Suburban railways in megacities exert a pivotal role in propelling urbanization and shaping urban agglomeration. However, previous study endeavors have overlooked the transformations occurring in urban expansion along suburban railways, with a particular dearth of attention on the spatio-temporal evolution of landscape ecology and urban function. Therefore, this study employs the megacity of Beijing as an example. It utilizes remote sensing and point-of-interest (POI) data spanning from 2008 to 2022 to construct an indicator system from two essential dimensions: urban form and function. We explored the spatio-temporal characteristics of alterations in urban expansion within the gradient buffer zone adjacent to the suburban railway network in Beijing. The results showed that: (1) The rates of urban expansion were highest in 2008–2013 and lowest in 2013–2018; moreover, suburban railways had the greatest impact on the built-up area within 2–4 km along the route, and the impact gradually decreased beyond 4 km. (2) The direction of urban expansion shifted northward in the direction of latitude and eastward in the direction of longitude from 2008 to 2022, with the shift in latitude being more distinct. (3) The number of urban functions gradually increased from 2008 to 2018, but the number of medical services suddenly increased and the number of other urban functions decreased from 2018 to 2022; in addition, urban functions other than scenic spots were mainly distributed in the main urban areas, with very few clusters distributed near stations. (4) The landscape shape index became more irregular and fragmented from the center along the route to the edge of the buffer zone from 2008 to 2013, and the degree of fragmentation was highest in the 2–4 km buffer zone. In summary, this paper analyzes the spatio-temporal characteristics of urban expansion along suburban railways through four indexes, namely expansion rate, expansion direction, urban function, and landscape shape, and the results of this study are of great significance to the development and planning of suburban railways in megacities.

Capacity-constrained mean-excess equilibrium assignment method for railway networks

The reliability and unreliability of travel time variability caused by stochastic train delays considerably influence passengers’ travel path choices. This paper proposes an equilibrium assignment method that can capture the passengers’ path choice behaviors considering both the reliability and unreliability of travel time variability in the railway network. The passengers’ travel path choices are modeled using the mean-excess travel cost (METC), which is the combination of the conditional expectation of travel cost exceeding the effective travel cost, and the endogenous advanced ticket booking cost associated with the rigid train capacity. In general, heterogeneous passengers with different risk-aversion attitudes toward stochastic train delays evaluate their travel options differently and have different requirements for successful transfer. Therefore, first, the passengers’ transfer options are modeled with the concept of METC based on the delay distribution of the two connecting trains. Subsequently, the METC of the passenger trips is calculated. A mean-excess passenger flow assignment model is formulated based on the user equilibrium condition. A path-based capacity-constrained passenger assignment algorithm is designed to solve the model. Moreover, three illustrative examples are presented to demonstrate the effectiveness of the model and solution algorithm.

Infrastructural Care: Repairing Railway Trains, Maintaining Mumbai’s Lifeline

ABSTRACT Mumbai’s suburban railway network is one of the largest, most densely-packed public transport systems in the world. Known as the city’s ‘lifeline,’ these trains carry eight million commuters every day and provide crucial connectivity. Drawing on fieldwork at a railway carshed, this article uses infrastructural care as an analytic to ethnographically explore how practices of preventive and corrective maintenance not only repair trains but are also crucial in maintaining spatiotemporal flows produced by urban infrastructures. Repair and maintenance involve a distribution and convergence of human and nonhuman agencies that simultaneously reveals the ontological multiplicity of trains while also stabilising them as sociotechnical assemblages. In doing so, repair attempts to render faults knowable to predict and prevent failures, which then instantiates new routines across the traction rolling stock. However, carshed engineers also face bureaucratic pressures of ensuring both punctuality and safety, thus necessitating the managing of maintenance within increasingly saturated capacities.

Combined Optimization of Maintenance Works and Crews in Railway Networks

This study develops optimal maintenance schedules for train lines, a critical endeavor ensuring the safety, efficiency, and reliability of railway networks. The study addresses the combined scheduling problem of maintenance works and crews on the railway networks. The baseline scheduling model is initially established with the primary objective of allocating maintenance tasks efficiently while adhering to pertinent constraints, encompassing task grouping and cost minimization. Subsequently, this baseline model is enhanced through the integration of crew scheduling, wherein work crews are strategically assigned to execute predefined tasks, thereby facilitating effective workload distribution. The combined maintenance work and crew scheduling problem is mathematically formulated as a binary linear programming model, enabling the attainment of globally optimal solutions. Comparing the outcomes of our enhanced model, which incorporates both maintenance works and crew schedules, with the baseline model that solely addresses maintenance works, we reveal that task grouping in accordance with predefined conditions leads to reduced overall costs by minimizing maintenance duration during various periods. Additionally, the judicious distribution of workload among the crews ensures comprehensive coverage of all essential tasks. These findings underscore the significance of our proposed approach in enhancing the operational efficacy and economic viability of railway maintenance scheduling, thereby offering valuable insights for practical implementation and future research endeavors.

A comparative analysis of the economic efficiency of coal mining and transportation along the Northern Sea Routes to international consumers from the Taymyr Peninsula deposits

Subject. This article discusses the issues of modernization of transport infrastructure, as well as the policy of Russia's Turn to the East. Objectives. The article aims to find the most effective approach to the development of mineral deposits located in the Arctic Zone of the Russian Federation, and assess the prospects for expanding mineral exports to China, India and other Asian countries. Methods. For the study, we used a comparative analysis. Results. The article finds that mineral resource centers, the creation of which is provided for by the Strategy for the Spatial Development of the Russian Federation, will contribute to the strengthening of economic activity in the Arctic. The volume of explored coal reserves on the Taymyr Peninsula makes it possible to create a large energy cluster. Conclusions. The extraction of hydrocarbons in the Arctic and the modernization of the corresponding infrastructure can bring more benefits in the case of parallel development of fields localized near the Northern Sea Route. In the northern regions of Russia, it is necessary to develop a network of roads and railways, which will increase traffic flows, on which success in the implementation of the Turn to the East policy depends.

Railway Network, Industrialization, and Development of Langsa, Aceh in 1907—1943

This study aims to reveal the railway networks, industrialization, and development of Langsa, Aceh in 1907-1943s. In the early 1900s, Langsa was designed as a Government Center and a new economic center on the East Coast of Aceh. However, Langsa was not yet connected to the railway networks, so it was necessary to build a railway line as one of the supporting infrastructures. The construction of the railway networks changed many things, ranging from urban landscape, economy, politics, to socio-culture. To pursue the aim of this study, historical methods consisted of heuristics, source criticism, interpretation and historiography were applied. The sources used were colonial archives, contemporary newspapers, contemporary magazines, and other relevant sources. This study found that the construction of the railway networks in Langsa was part of the Dutch colonial government's strategy to maximize economic benefits in the eastern coastal region of Aceh by building connectivity from the North and South regions. The development of the railway networks also had an impact on the growth of the economy, the mobilization of a dynamic population, the growth of good infrastructure for travelers, facilitating communication networks, to encourage the emergence of various types of new professions. However, the construction of the railway networks played a role in environmental damage in the eastern coastal region of Aceh as well as gave insignificant impact on the development of Aceh's indigenous human resources.

Enhancing Railway Network Safety by Reproducing Wheel–Rail Electrical Contact on a Laboratory Scale

Ensuring the safety of rail networks requires precise detection of a train’s position on a track section. This is achieved using a “track circuit” system, in which the wheel–rail electrical contact is the key to maintaining the system’s reliability. However, any degradation of this contact can lead to a track circuit malfunction known as “deshunting”, creating a serious safety risk for the rail network and for passengers. This paper presents a refined approach to this concern by implementing a laboratory-scale test bench. The main objective is to reproduce the wheel–rail electrical contact under controlled conditions to better understand the various aspects of this contact. The criteria governing the dimensioning of the test bench at reduced scale are based primarily on mechanical considerations. In this study, a series of tests were carried out to investigate the behavior of the electrical resistance as a function of various parameters such as load, current and time. An original homemade salt spray system was designed and used for obtaining controlled rail oxidation. Our preliminary results highlight the impact of these factors on the electrical resistance, providing valuable insights for future advances in rail safety technology.

Multi-vehicle accessed railway vehicle-grid system stability analysis and optimization based on OLTC

The interaction between Electric Multiple Units (EMUs) and the traction network can lead to oscillation problems due to electrical mismatch. The stability between the EMUs and the traction network is difficult to ensure because of the multiple operation points and variable operation modes of EMUs. To analyze the system stability, impedance-based methods are commonly used. However, existing impedance-based stability analysis methods require identifying system transfer functions, which can introduce under- or over-fitting problems. To address this issue, this paper introduces an optimized open-loop based stability analysis method for multi-vehicle accessed vehicle-grid system, which effectively assesses the impact of vehicle operating points and modes on system stability. In addition, we propose an On-Load Tap Changer based method to enhance the voltage stability of railway traction networks. By optimizing traction network voltage, the impedance characteristics of vehicles are also modified, thus enhancing system stability. Finally, we validate the efficacy of the proposed method through case studies based on an actual railway train schedule diagram.

Railway College in Derbent: road 120 years long

In 2023, the state budgetary professional educational institution of the Republic of Dagestan “Railway College” (Derbent) celebrated its 120th anniversary.Under the conditions of an intensively operating network of railways, the professional qualities and level of training of railway specialists are of particular importance. The development and improvement of a complex railway complex is directly related to and depends on the level of personnel training.The history of creation and the long way of development and improvement of the Derbent College is of interest even today. It is important to know your past, to remember the path that our railways have traveled, to do everything so that the transport personnel training system always corresponds to the level of tasks solved by transport.

FOREIGN ECONOMIC ACTIVITY IN THE TYVA REPUBLIC: NEW OPPORTUNITIES

The dynamics of foreign economic activity in the Republic of Tyva for 2015–2021, the change in the foreign trade turnover of Tuva with Mongolia, with countries of near and far abroad are analyzed. Trade turnover of Tuva with external partners has a positive balance. A significant share of foreign trade turnover falls on non-CIS countries. It is noted that the nature of trade and economic relations with Mongolia is influenced by the relative development of the transport system of Tuva, the republic does not have a railway connection with the rest of the country. New opportunities for further expansion of interregional and strengthening international economic relations between the two neighboring regions are due to the possibilities of solving infrastructure problems, joining the region to the Russian railway network. It is proposed to use new tools for developing foreign economic relations, expanding the space for interregional cooperation, innovative approaches to attracting investments, and strategies for developing the region's foreign economic activity. The creation of a cross-border special economic region and a cross-border corridor Russia — Mongolia — China are substantiated.

Errors of professional activity of transport system operators in conditions of high information load

Introduction. Ensuring traffic safety on the railway network involves the development of complex predictive models that take into account both the state of technology and the influence of the "human factor" in order to minimize the risk of erroneous actions and prevent accidents.
 The study aims to research the mistakes of railway transport operators (using the example of locomotive crew workers).
 Materials and methods. The authors have conducted the study on the basis of analysis of the database of erroneous actions of employees of locomotive crews (2020–2021), submitted by the Research Institute of Railway Transport (according to the agreement on joint scientific cooperation between the Izmerov Research Institute of Occupational Health and Research Institute of Railway Transport).
 Results. The database recorded 104,515 cases attributed to 291 types of erroneous actions with qualitative differences that reflected the degree of risk to the safety of train traffic. The most common categories of violations related to the maintenance of train documentation, errors in locomotive control, non-compliance with the speed limit, disconnection of locomotive safety devices, speeding, brake control violations, violations of the rules of negotiations, the passage of a forbidding signal. In relation to employees who committed violations, the most common disciplinary penalties were identified (analysis of the case in technical classes, deprivation of an employee of a bonus in the amount of 25, 50 and 100%). In a number of cases, several different disciplinary penalties were applied to one employee at the depot for the same violation.
 Limitations. Inability to get access to the protocols of psychophysiological examination of employees of locomotive crews.
 Conclusion. The obtained scientific results allow us to assert that the productivity and safety of the operator's activity correlates with the level of professional training and the mechanisms of its inclusion in the activity. The prospects for further research of the problem of ensuring the safety of locomotive crews' employees consist in a detailed study of the combined effect of factors of the working environment and the labor process in conditions of increasing labor intensity, increasing speeds and volumes of railway transportation. It is necessary to study the ratio and role of such indicators as reliability, professional suitability and readiness of the employee to perform functional duties in the event of an emergency.
 Ethics. The study was carried out on the basis of documents submitted by JSC "Russian Railways". The documents contained the number and typology of mistakes made by employees of locomotive crews in the period 2020-2021. The scientists have conducted the study in accordance with the Ethical principles of anonymity, confidentiality, respect for the rights of the subject of the study, the principles of scientific and impartiality.

Digital Twin for condition based maintenance within a railway infrastructure testing lab

This article presents a digital twin development in a railway case, in order to improve operations and maintenance decisions, aligned with an asset management strategy. A digital framework for the sustainable management of these assets is defined with the purpose of facilitating the implementation on a cloud platform, searching the generation and sharing of the produced models and the evaluation from different perspectives. The developed digital twin allows for the digital representation of railway lines and vehicles, the connection between different entities based on an ontology, the management of data ingestion and storage, and the administration of models for the detection, diagnosis, and prognosis, as well as the representation and control of the level of risk of the assets. When emulation of railway line degradation is searched, different types of data are combined, from on-board sensors in railway vehicles, and physical behaviours, up to machine learning algorithms for estimation. In this way, the degradation behaviour model for the railway line is shown and validated through intelligent models easily replicated in several areas of the railway network, showing risk levels for each one.

DETERMINATION OF THE FREQUENCY OF NATURAL OSCILLATIONS OF THE ELEMENTS OF THE MECHANICAL SYSTEM OF THE MOTOR CARRIAGE ROLLING STOCK

The article is devoted to highlighting the peculiarities of determining the frequencies of natural oscillations of the elements of the mechanical system of modern rolling stock. A significant volume of passenger transportation in suburban traffic on railway networks of Ukraine is carried out by the operating fleet of rolling stock, most of which are operated overtime. Taking into account the relatively slow pace of renewal of Ukrzaliznytsia's rolling stock fleet, scientific research aimed at maintaining a high level of technical and economic indicators of electric trains in operation becomes especially important. Therefore, research aimed at improving performance indicators of structural elements of rolling stock should be considered relevant. As one of the most responsible units of the mechanical system of modern rolling stock, the crew part can be singled out, which includes a traction electric drive, during the operation of which the phenomenon of jolts is observed in some modes of operation. Such a phenomenon is observed in resonant modes of operation, that is, the coincidence of the frequencies of natural and forced oscillations, which negatively affects the reliability and durability of the mechanical system as a whole. Therefore, the task of identifying resonant frequencies and eliminating the manifestation of the negative phenomenon of resonance arises. One of the possible ways to solve the given problem is to adjust the operation of the traction drive mechanism in non-resonant modes, which in turn requires research on the torsional oscillations of the mechanical drive system. The article presents an approach using geometric models of the design elements of the traction drive of electric trains, the corresponding mathematical model, and the results of modeling the shape of the frequency of natural oscillations of the traction drive of an electric train. Based on the results of the calculations, it was determined that the form of natural oscillation frequencies of the considered mechanical system has a two-node character. The proposed approach is based on the use of a tabular form of calculation of recurrent formulas. Based on the results of the research, recommendations are given for the further use of the obtained results. Keywords: motor-wagon rolling stock, electric train, traction drive, self-oscillations.

Seismic behaviour assessment and rehabilitation of a masonry three‐arched bridge

AbstractMany existing historical masonry arch bridges used in the road and railway networks are still in service. However, most of them show a structural performance deficit due to several factors. This study deals with the seismic behavior assessment of an existing masonry three‐arched railway bridge through a nonlinear, non‐adaptive static analysis carried out by a three‐dimensional Finite Element model. Input data were collected from a variety of sources. The structural analysis showed a risk index that was not in compliance with the limit values suggested by current European Standards. In order to improve the structural reliability of the masonry arch railway bridge, a traditional structural rehabilitation was proposed and designed. The bottom faces of the arches and the piles of the masonry bridge were strengthened by reinforced concrete thin slabs and reinforced concrete jackets, respectively, all adequately connected to the existing structure by using steel bar connectors. Finally, a nonlinear analysis of the strengthened structure showed that the new risk index satisfied the seismic vulnerability verification. The proposed structural rehabilitation using traditional techniques appears to be a viable but not unique solution to improving structural reliability.

Buffer Time Optimization in the Function of Timetable Stability

Timetable stability depends on the regularity of trains. Any deviation from the planned timetable leads to its instability. Railway network characteristics determine the capacities of the transport service. Depending on the capacity calculation method, time components are added to the minimum headway to ensure timetable stability. The UIC 405 method is simple and can be used on all railways. The disadvantage is that the calculations are based on average data. According to the method, the minimum headway consists of the time of the average headway interval, additional time and the buffer time. The additional time is precisely defined by the number of APB sections, while the buffer time is in the average value. When creating the timetable, the goal is optimal utilisation of the infrastructure. If the headway is too long, the capacity is not used, and if it is too short, timetable instability will ensue. Instead of averaging, this work calculates a buffer time that depends on the ratio of the travel time of the previous and the following trains. In this way, the headway is optimised and the calculation of the UIC 405 method is improved.

Evaluation of Railroad Bridge Foundation Response to Insulation Application under Cold Regions

To establish an integrated railroad network in the Korean Peninsula, in preparation for the unification era presented in the 3rd National Rail Network Construction Plan (2016–2025) and the Railroad Industry Development Basic Plan, a preemptive response to construct railroad infrastructure considering the low temperature in North Korea during winter is essential. In this study, extensive numerical analyses were conducted to evaluate the behavior of railroad bridge foundations while accounting for the climate and geological conditions of North Korea. Furthermore, we proposed additional items that need to be addressed in the current railroad roadbed design standards. Eventually, we found that taking measures, such as application of insulation, to alleviate frost damage due to the increase in the adfreezing strength of railroad bridge foundations in cold regions where the freezing index is more than 1,000 ℃ day is necessary.

A Geospatial Analysis-Based Method for Railway Route Selection in Marine Glaciers: A Case Study of the Sichuan-Tibet Railway Network

Marine glaciers play a significant role in shaping landforms due to their erosive nature coupled with their surrounding environment. During this process, they pose a natural hazard threat to man-made infrastructure. The dynamic nature of these glaciers poses a particular threat, especially to railway infrastructure constructed in remote areas with glacial activity. Substantial research has been undertaken on the role of threats posed by marine glaciers to railway infrastructure. However, a detailed study of favorable glacier landforms prior to railway construction has yet to be explored. In this study, we propose a geospatial analysis-based method to determine the favorable most landforms shaped by marine glaciers for railway network route selection. This study provides a novel approach by first analyzing the availability of four major favorable landforms shaped by marine glaciers (glacier canyons, valley shoulders, moraine terraces, and ancient dammed lake basins), then proposes a railway route selection method for marine glacier distribution areas involving three steps. First, it is necessary to understand the basic situation of regional glaciers; then, to determine a feasible location for the railway based on judgment of the direct and indirect action areas of glaciers; and finally, through a thematic study of glacial geomorphology, to devise corresponding strategies for using glacial landforms to optimize the railway route. In order to verify the feasibility of the proposed method, it was implemented in the Palong Zangbo watershed of the Sichuan–Tibet railway network. Utilizing the power function method, the glacier basin areas of 22 glacier canyons along the Sichuan–Tibet railway line were identified and the maximum annual average velocity of 75 glaciers over the past ten years was calculated by offset tracking technology. The results indicate that the proposed optimization strategies utilizing glacier canyons for a short and straight route scheme and leveraging moraine terraces for a high-line scheme can provide comprehensive guidance for railway route selection in marine glacial areas.

Deep Q-Network Approach for Train Timetable Rescheduling Based on Alternative Graph

The disturbance of local areas with complex railway networks and high traffic density not only impedes the efficient use of rail networks in those areas, but also propagates delays to the entire railway network. This has motivated research on train rescheduling problems in high-density local areas to minimize train delays by modifying their planned arrival and departure times. In this paper, we present a train rescheduling method based on Q-learning in reinforcement learning. More specifically, we used deep neural networks to approximate the action-value function, and the underlying Markov decision process (MDP) is based on the alternative graph formulation for the train rescheduling problem. In the proposed MDP formulation, the status of the alternative graph corresponding to the current schedule is defined as the state, and the alternative arc corresponds to the action the agent can take. The MDP is approximately solved via deep Q-learning in which deep neural networks are used to approximate the action-value function in Q-learning. Although the size of the alternative graph depends on the number of trains, our MDP formulation is independent of the number of trains, which makes the proposed method more scalable. The evaluation of the method was performed on a simple railway network and a real-world example in Seoul, South Korea, with randomly generated initial train schedules and train delays. The experimental result showed that the proposed method is comparable to the mixed-integer-linear-programming (MILP)-based exact approach with respect to the quality of the solution.