Railway Capacity Research Articles

The Effect of Level Crossing on the Railroad Line Capacity

Changing the railway line from single track to double track will increase the railway line capacity, which means there is an additional number of train trips. Even though it has become a double track, the train trip still passes through a level crossing. If the number of train trips increases, it will result in more frequent level crossing gates being closed, or it can also result in more extended gate closing times. When the level crossing gate is closed, there will be a road traffic conflict; the traffic will stop and form a queue. The more often the level crossing gate is closed, the more road traffic conflicts will increase. By using the Indonesian method for calculating the railway line capacity, the change from single track to double track will increase the railway line capacity by 2.35 times. However, this calculation has not considered the existence of a level crossing, so this study aims to determine the amount of the railway line capacity that can be achieved, which is influenced by the level crossing without significantly increasing road traffic conflicts. The research method was carried out by taking data on train trips and road traffic at the level crossing that exists today, which is still a single line, then simulating the conditions when it has turned into a double track. Simulations are carried out by adding the number of train trips according to the double track capacity. Simulation results showed that at the level crossing, the factor affecting the increase in the railway capacity line is the headway time between the closing of the level crossing gate. For headway time values below or equal with 2.5 minutes, the line capacity increases by 1.5 times the single-line capacity. As for the headway time value above 2.5 minutes, the line capacity increases to 2.35 times the capacity of the single line. From this research, it can be concluded that the level crossing affects increasing the capacity of the railway line. To achieve maximum railroad capacity, the headway time between closing the level crossing gate must be more significant than 2.5 minutes.

A Train Protection Logic Based on Topological Manifolds for Virtual Coupling

Virtual coupling is a promising innovation aimed at increasing railway capacity. Compared to current railway signaling systems, it allows two or more trains to run with reduced headway between them. However, such reduced headways are a challenge to safety. In this work we consider this challenge by formally describing and verifying an approach to virtual coupling. We propose a general modeling method based on topological manifolds to describe the protection logic for virtual coupling train control systems. We also describe the basic train control elements in topological terms and analyze the line condition of our virtual coupling logic. We establish that the line condition safety requirements and its representation as a manifold are equivalent and further provide a formal definition of the concept of a movement authority with manifold notations. This allows us to consider the dynamic behavior of trains and a series of theorems that establish the correctness of our protection logic for virtual coupling. Finally, we apply the presented methods to a case study. The results show that the proposed method provides a suitable way to realize a virtual coupling logic safely.

Analysis of Electromagnetic Processes in a Traction Network in Connecting a Reactive Power Compensation and Harmonic Filtering System at a Sectioning Station

To increase the railway capacity, a controlled static reactive power generator is connected at a sectioning station. To reduce the cost indicators of the controlled installation and decrease the power losses, a combined reactive power compensation and harmonic filtering system is proposed, in which the following components are connected in parallel: an uncontrolled bank of shunt capacitive compensation with reduced cost indicators and a static reactive power generator. The total reactive power of the combined system is equal to the specified one. At low traction loads, the static generator operates in the mode of inductive power generation, due to which reactive power is smoothly regulated over the entire load range. Since the existing generator power is reduced by 2-3 times (at the same set power), the total increased power losses are also reduced. For analyzing the electromagnetic processes in the traction network, an electric rolling stock nonlinear model is developed. The article shows how the traction current higher harmonic components are filtered and demonstrates the combined system operability in terms of reactive power compensation under various traction loads by analyzing the waveforms of electromagnetic processes.

Capacity-Oriented Train Scheduling of High-Speed Railway Considering the Operation and Maintenance of Rolling Stock

The capacity of some busy rail lines is increasingly tight and passenger demand far exceeds the railway capacity. To schedule as many trains as possible in order to satisfy more transportation demands, we studied the capacity-oriented train scheduling problem. While most approaches focus only on increasing the capacity of the rail line, this research considers both the time-space distribution of transportation demands and the operation and maintenance of rolling stock. To solve this problem, we first constructed a time-space network to describe the time-space path of rolling stock. We then proposed an integer planning model with rolling stock maintenance and the OD service frequency constraints to maximize the number of running arcs in rail sections. After decomposing this model by introducing some Lagrangian multipliers to relax its hard constraints, we proposed a Lagrangian relaxation-based decomposition algorithm, including two path search sub-algorithms for rolling stock to optimize both the relaxed and the feasible solutions. Finally, we conducted a computation study on a practical double-track high-speed railway line to test the performance of this algorithm. It reports that the train timetables and the operation of rolling stock are well managed.

A bidirectional quasi-moving block cellular automaton model for single-track railways

In this paper, a bidirectional quasi-moving block cellular automaton model for single-track railways is proposed to simulate the impact of quasi-moving block on the passing capacity of single track railway. The rules of train departure, meeting, entering the station and running in the section are formulated and the Naqu–Lhasa section of the Qinghai–Tibet Railway is taken as an example for simulation. The results show that, under the quasi moving block, with the changes of the mixed ratio and stop time of freight train, the passing capacity is improved compared with the currently adopted automatic inter-station block. Besides, it is found that the passing capacity is the largest under equal station spacing conditions, indicating that the distance between stations should be minimized in the preliminary line design.

Investigation and Prioritization of Railway Reconstruction Projects by Using Analytic Hierarchy Process Approach Case Study: Kerman and Southeastern Areas in Iranian Railways

Transportation development is one of the important goals of countries which is associated with economic and social development. Therefore, expanding the transportation infrastructure and construction has always been a key issue for managers in developed and developing countries. Due to the high costs of infrastructure projects in the transportation industry, especially railways as the safest and the most cost-effective mode of transportation, the financial resources must be managed with great sensitivity and precision. In current economic conditions, various methods have been proposed for decision-making in transportation infrastructure projects and prioritization of railway reconstruction projects. In this research, different decision models to prioritize transportation infrastructure projects are reviewed and according to the selected AHP (Analytic Hierarchy Process) model, railway reconstruction projects in Iranian railway networks are prioritized. In this regard, first, reconstruction projects have been reviewed from a technical and economic point of view, and then prioritization has been done according to the weight of effective criteria in the projects. In this study, important criteria for prioritization in terms of importance are considered as: Cost of Reconstruction, Train Speed Restriction, Allowable Speed, Railway Capacity, Traffic, Time, and Railway Track Quality. The effect of cost of reconstruction criterion is about 12 times greater than the time criterion and the output of the model showed that Jalalabad-Golezard block is the first priority for reconstruction in the area of Kerman and Southeastern in Iranian Railways.

A Two-Phase VIKOR Model for Track Layout Evaluation of Passenger Rail Stations

Passenger stations are transit hubs where several railway lines interchange. They have important roles in providing train operations and passenger services. Interrelations between track layouts and technological performances are important for reducing bottleneck effects and raising the operational effectiveness of rail networks. To the best of our knowledge, in previous research the assessment of track layouts has not been considered with respect to various technological aspects including railway operations, safety, and passenger services but rather as a single criterion for analysis of different individual performance indicators. We propose a new two-phase decision making approach for the complex evaluation of track layout alternatives. The first phase model is a VIKOR method for ranking track layouts by criteria related to: railway capacity, safety issue, and passenger-pedestrian fluctuations. Next, in the second phase, we use marginal analysis to find Pareto front and compare the alternatives ratings by calculating performance-benefit coefficients. To show the applicability of the proposed model, we employ an illustrative example of a passenger rail station and evaluate six different track layout alternatives. The effectiveness of the proposed model is demonstrated comparing the proposed two-phase model with traditional VIKOR.

INCREASING THE CAPACITY OF RAILWAYS WITH THE INTRODUCTION OF VIRTUAL TRAIN COUPLING

This article discusses the effectiveness of the implementation of a virtual train coupling on the capacity of railways. The article compares the possible ways of organizing a virtual coupling: the use of radio block centers and the use of a "virtual coupling" in the direct exchange of information between locomotives. Technical problems and technological problems that arise when implementing this technology are considered. In conclusion, the scheme of effective application of virtual coupling technology for solving the problem of increasing the capacity of railway sections is constructed. It is concluded that the task of increasing the capacity requires an integrated approach to the solution, taking into account all the technical and technological features of the road.

Increasing the carrying capacity of the Mongolian railway when creating new transport corridors

Increasing the carrying capacity of the Mongolian railway when creating new transport corridors

Aspects of design and calculation of a railway track intended for dedicated passenger lines

The article considers issues of application of dedicated passenger lines for intertown and interregional transportation on the railways of the Russian Federation, which in the future will accelerate passenger traffic due to changes in transportation technology, increase the carrying and throughput capacity of railways, reduce construction costs and current maintenance, and optimize the need for infrastructure development. The structures of the track superstructure used for the transportation process at the present time were developed and implemented taking into account the mixed traffic — passenger and freight. Growth of axle loads in freight traffic, as well as the length of trains, presupposes the strengthening (weighting) of the standard structures of the railway track to possibly ensure the guaranteed safe passage of more than 1 billion gross tonnage. At the same time, exclusively for passenger traffic, the typical design of the railway track is redundant and can be optimized in terms of reducing the materials of the track superstructure with a simultaneous change in the configuration of repair schemes and current maintenance conditions. The article presents an assessing the possibility of using a “passenger” track structure on dedicated passenger lines for intertown and interregional transportation according to the criteria of the allowable margin of safety in the environment of fnite element analysis — the most progressive method for calculating structures undergoing complex loading. The article presents the results of calculations of the stress-strain state of a railway track of various confgurations, including promising lightweight versions with R50 rails and reinforced concrete sleepers with under sleeper pads. Based on the calculations performed, recommendations are given for the areas of application of the considered track confgurations from the point of view of permissible stresses in its elements.

Robotic Railway Multi-Sensing and Profiling Unit Based on Artificial Intelligence and Data Fusion.

This article presents the research and results of field tests and simulations regarding an autonomous/robotic railway vehicle, designed to collect multiple information on safety and functional parameters of a surface railway and/or subway section, based on data fusion and machine learning. The maintenance of complex railways, or subway networks with long operating times is a difficult process and intensive resources consuming. The proposed solution delivers human operators in the fault management service and operations from the time-consuming task of railway inspection and measurements, by integrating several sensors and collecting most relevant information on railway, associated automation equipment and infrastructure on a single intelligent platform. The robotic cart integrates autonomy, remote sensing, artificial intelligence, and ability to detect even infrastructural anomalies. Moreover, via a future process of complex statistical filtering of data, it is foreseen that the solution might be configured to offer second-order information about infrastructure changes, such as land sliding, water flooding, or similar modifications. Results of simulations and field tests show the ability of the platform to integrate several fault management operations in a single process, useful in increasing railway capacity and resilience.

Compositional modeling of railway Virtual Coupling with Stochastic Activity Networks

The current travel demand in railways requires the adoption of novel approaches and technologies in order to increase network capacity. Virtual Coupling is considered one of the most innovative solutions to increase railway capacity by drastically reducing train headway. The aim of this paper is to provide an approach to investigate the potential of Virtual Coupling in railways by composing stochastic activity networks model templates. The paper starts describing the Virtual Coupling paradigm with a focus on standard European railway traffic controllers. Based on stochastic activity network model templates, we provide an approach to perform quantitative evaluation of capacity increase in reference Virtual Coupling scenarios. The approach can be used to estimate system capacity over a modelled track portion, accounting for the scheduled service as well as possible failures. Due to its modularity, the approach can be extended towards the inclusion of safety model components. The contribution of this paper is a preliminary result of the PERFORMINGRAIL (PERformance-based Formal modelling and Optimal tRaffic Management for movING-block RAILway signalling) project funded by the European Shift2Rail Joint Undertaking.

An Integrated Methodology for the Multi-Objective Optimization of Port Railway Capacity: The Case Study of the Port of Trieste

The relevant pressure exerted on ports following the advent of globalization and containerization has contributed to transform the role of such intermodal transport facilities, increasing their complexity with reference to both performed activities and involved actors. The potential of solid hinterland connections in enhancing port competitiveness has sustained the larger embracement of the railway mode, which has proved to be a financially and environmentally sustainable solution, especially on long hauls. However, the limited residual capacity currently characterizing several railway network and nodes may threaten the accommodation of additional future traffic volumes and, thus, it requires the adoption of a coordinated strategy to more efficiently manage existing railway infrastructures, other than the realization of some new ones. In this regard, an integrated methodology has been developed to specifically model, simulate and optimize port railway processes, as part of a more complex system, imposing the maximization of capacity with the concurrent minimization of used shunting locomotives, to varying of infrastructural and operational conditions. This combination of techniques has been applied to the case study of the Port of Trieste, Italy, showing the greater influence of tracks availability over changes in the operational conditions, in terms of a shorter duration of specific administrative tasks and the employment of more shunting locomotives.

STATE AND DIRECTIONS OF TRAVEL FARM DEVELOPMENT BELARUSIAN RAILWAY

The track economy is the most important branch of the republic's railway transport, on the state of which the robotic capacity of the entire railway depends. The normal functioning of the track facilities is impossible without the use of modern resource-saving technologies, high-performance and modern technology, without the regular provision of materials for the repair and maintenance of the track. The purpose of the article is to analyze the state of the track and its main elements. The main task is to ensure the safety of train traffic. As shown by the safety analysis in 2020, 9 events were admitted related to the violation of traffic safety rules and the operation of railway transport. To ensure the safety of train traffic, it is necessary to study a number of issues on the maintenance of continuous-welded rail strings, including avoiding lateral wear by re-laying them, reducing the number of defective rails, including through the introduction of aluminothermic welding and surfacing of rails. In 2020, due to the implementation of the repair program and according to the actual state of the track, train speeds were increased by almost 350 km. In order to further strengthen the track facilities of the Belarusian Railway, ensure the safety of train traffic and increase the efficiency of planning of labor and material resources, in 2020, the Program for the repair of railway tracks of the Belarusian Railway for 2021 - 2023 was developed. The implementation of the Program for the repair of railway tracks of the Belarusian Railways for 2021 - 2023 will allow to exclude kilometers of railway tracks with overdue repairs available as of 01.01.2021 and prevent an increase in their number in subsequent years.

INVESTIGATION OF THE THROUGHPUT OF RAILWAY AND ROAD TRANSPORT OF ANGREN-POP THROUGH THE KAMCHIK PASS AND WAYS OF ITS FURTHER IMPROVEMENT

The article is devoted to the analysis of the current state of the capacity and carrying capacity of roads and railways passing through high mountain areas, its prospects, measures to be taken to further improve the existing performance. In the example of the Whip Pass.

PREFACE

PREFACE

Analysis of Klavdii Semyonovich Nemeshaev’s activities as the Minister of Railways of the Russian Empire

The article continues the series of publications devoted to the assessment of activities of the heads of the Ministry of Railways of the Russian Empire. In this article, the authors attempt to systematize and analyze historical data on the activities of Klavdii Semyonovich Nemeshaev as the Minister of Railways of the Russian Empire. There are numerous biographical studies devoted to K. S. Nemeshaev, but little is known about his activities as a minister, and to date the data are scattered and not systematized. The analysis of archival materials, scientific publications, memoirs of Nemeshaev's contemporaries and colleagues allowed us to conduct a detailed assessment of his activities and ministerial policy. It has been found that despite his short term of office, Nemeshaev's consistent policy and extensive managerial experience allowed him to carry out two significant reforms in a short time. The first one involved redistribution of the state-owned railway lines between separate local administrations and merging them into larger groups, which was important in terms of improving their operations and facilitating the cost efficiency, as well as speeding up freight traffic. In opinion of the authors of this article, another important achievement of Nemeshaev as the Minister of Railways was the establishment in 1906 of the central, local and district committees regulating mass transportation of goods. This was the first centralized measure aimed at managing the rolling stock. Nemeshaev's extensive managerial experience, high erudition and energy also led to prominent outcomes in some other areas of the Ministry operation. Attempts were made to create syndicates of shipowners in river transport. Modernization of river and sea vessels was carried out. Works on projects for the development of the Northern Sea Route has begun. The article also assesses the development and construction of railway network in the Russian Empire during Nemeshaev's office, in particular, of the Amur Line and Moscow Encircle Railway, as well as the increase in the capacity of the Trans-Siberian Railway. It has been found out that K. S. Nemeshaev paid great attention to various social aspects of railway employees’ activities. The article also highlights the legislative policy of the Ministry of Railways of that period. Nemeshaev's participation in the preparation of the French scientist’s Paul Pelliot and the Russian officer’s Carl Gustaf Mannerheim joint trip to China has been analyzed. Due to the mass replacement of light and worn-out rails on state-owned railways with heavier ones and the need to discharge a significant number of steam locomotives built in the 1850s and 1860s, an introduction of more powerful steam locomotives was expedient. The article discusses K. S. Nemeshaev's contribution to the development of technology and the introduction of a new type of freight steam locomotive for state-owned railways. Nemeshaev's political views have also been assessed.

Increasing railway capacity with the installation of reactive power compensation

The article considers existing regulated installations of transverse capacitive compensation for increasing the capacity of sections of the traction network of 25 and 2×25 kV of Russian railways. Characteristics of a static reactive power generator based on bipolar IGBT transistors (manufactured by LLC NPP “RU-Engineering”, Naberezhnye Chelny), a switchable filtercompensating unit (manufactured by the Gorkovskaya Railway and the Nizhny Novgorod branch of SamGUPS), a three-stage switchable filter-compensating unit. To increase the capacity, all installations are switched on at the traction network sectioning posts. Long-term operation of the static reactive power generator and switchable filter-compensating unit have proven their operational efficiency. At the same time, the following upgrades are proposed: in a static reactive power generator it is proposed to reduce the installed power, replacing it with unregulated compensation, and in a switchable filter-compensating installation, it is proposed to switch in 400–500 V steps to normalize the traction mode of the electric rolling stock.It is shown that in terms of technical characteristics, a switchable filter-compensating installation with a thyristor switch is not inferior to a static generator of reactive power in terms of increasing the capacity, and in some respects it surpasses it. On the whole, in terms of payback period, a switchable filter-compensating installation surpasses a static generator of reactive power due to the high cost of the latter. The following options for using the considered installations are proposed. With the required power of transverse capacitive compensation units up to 5–6 MVAr, to increase the capacity, switchable filter-compensating units should be installed. Taking into account real loads, such a solution will be implemented at most sectioning posts. For installations with a capacity of more than 5–6 MVAr, the option of using a static reactive power generator of reduced power should be considered: at high loads, its efficiency will increase.

SAT modulo discrete event simulation applied to railway design capacity analysis

This paper proposes a new method of combining SAT with discrete event simulation. This new integration proved useful for designing a solver for capacity analysis in early phase railway construction design. Railway capacity is complex to define and analyze, and existing tools and methods used in practice require comprehensive models of the railway network and its timetables. Design engineers working within the limited scope of construction projects report that only ad-hoc, experience-based methods of capacity analysis are available to them. Designs often have subtle capacity pitfalls which are discovered too late, only when network-wide timetables are made—there is a mismatch between the scope of construction projects and the scope of capacity analysis, as currently practiced. We suggest a language for capacity specifications suited for construction projects, expressing properties such as running time, train frequency, overtaking and crossing. Such specifications can be used as contracts in the interface between construction projects and network-wide capacity analysis. We show how these properties can be verified fully automatically by building a special-purpose solver which splits the problem into two: an abstracted SAT-based dispatch planning, and a continuous-domain dynamics with timing constraints evaluated using discrete event simulation. The two components communicate in a CEGAR loop (counterexample-guided abstraction refinement). This architecture is beneficial because it clearly distinguishes the combinatorial choices on the one hand from continuous calculations on the other, so that the simulation can be extended by relevant details as needed. We describe how loops in the infrastructure can be handled to eliminate repeating dispatch plans, and use case studies based on data from existing infrastructure and ongoing construction projects to show that our method is fast enough at relevant scales to provide agile verification in a design setting. Similar SAT modulo discrete event simulation combinations could also be useful elsewhere where one or both of these methods are already applicable such as in bioinformatics or hardware/software verification.

Increase of the throughput and processing capacity of the railway line mountain pass section by strengthening the devices of the system of traction power supply

According to the forecast target indicators values of the JSC “Russian Railways” integrated development project until 2023, it is necessary to increase the East Siberian railway capacity of the mountain-pass section of the Bolshoy Lug – Slyudyanka-II up to 137 pairs of trains per day. The freight trains number should be 107 pairs per day, a raft of pushing locomotives in the odd direction up to 19 units. The section transportation capacity will increase to 116.7 million tons per year. According to the specified operation parameters, with the growth of cargo turnover on the Irkutsk – Slyudyanka section by 2023, the available capacity shortage will be 14 pairs of trains. In freight traffic, if all provided reserve lines of the the regulatory schedule are used, the capacity deficit will be 11 pairs of various categories trains. The article offers a solution of the existing section power supply devices strengthening problem until the inter-train interval of 8 minutes is reached, for this purpose, the technical parameters of the section substations are considered, and the performance indicators that can provide reliable and cost-effective working conditions are determined. The operation conditions of a traction power network (TPN) of the Bolshoy Lug – Slyudyanka-II section under the existing traffic schedule and under the prospective train schedule are compared. Traction calculations have a special role, since they serve as the basis for drawing up optimal train schedules, determining the railway lines capacity, effectively placing separate points, traction substations, fuel depots, determining the locomotives electricity and fuel consumption rate, solving other practical problems. Traction operation calculation of the electrified mountain pass section of the Bolshoy Lug – Slyudyanka-II railway line was performed using the KORTES software package. The power supply parameters of a given section were used as input data: the separate points number and location, the current speed limits for trains on this section, the longitudinal profile of the railway track, the categories and types of trains that pass through the section, the trains weights and the electric rolling stock types used in the calculation.