Railway Freight Research Articles

Cyber security of railway cyber-physical system (CPS) – A risk management methodology

Along with the increasing application of different cyber-physical systems (CPSs) to connect various components in the rail industry, rising connectivity through communication technologies has also introduced cyber threats against rail-CPSs, causing failures with huge consequences. Implementations of rail-CPSs demand proactive identification, clear-cut definition, and proper handling of their cyber security risks. In this paper, we formulate a risk management methodology for cyber security in rail-CPSs and conduct a retrospective case study on the Advanced Train Control System (ATCS) that has been deployed in many U.S. freight railways. The methodology provides two alternative approaches to fill knowledge gaps in contingency preparation, threat prevention, consequence analysis, and security risk mitigation. In the case study, we demonstrate two cyber threats of ATCS, using attack sequence modeling and consequence analysis, and provide recommendations for risk mitigation. By practicing the methodology with the case study, this work can be used as a general reference to conduct cyber risk management and cyber-robustness evaluations for other existing systems.

Key Technologies of Physical and Virtual Test Rig for Railway Freight Car body

On the one hand, considering that the traditional fatigue method of railway freight cars is based on damage as a parameter, the influence of stress waveform cannot be considered. On the other hand, physical experiments have the characteristics of lag, long period, and high cost. The full-scale physical test and virtual test of car body are carried out. First of all, the data processing method of small deletion and the inverse problem load acquisition method based on data to data are proposed. Secondly, the dynamic stress calculation method with the bench as the boundary is proposed. Finally, taking the obtained load as the input of the physical and virtual bench, a new fatigue test method for simulating the running attitude of the car body line is completed. The acceleration RMS error of the C70E gondola body is less than 6%, the stress RMS is less than 13%, and the equivalent mileage is 3.125 million highway test results show that the car meets the life requirements of the car body. The inverse problem analysis results of virtual and physical tests are basically consistent, and the study of this method provides a basis for improving the fatigue reliability of freight car bodies.

China’s Transport Land: Spatiotemporal Expansion Characteristics and Driving Mechanism

The literature about changes in land use includes many studies of global sustainable development goals, while studies of transport land expansion have been relatively scarce. In this paper, we present an analysis of the spatiotemporal characteristics of transport land expansion in China’s 31 provinces from 2009 to 2017, applying the spatial Dubin model to identify the factors that influenced changes in per capita transport land area (PCTLA). The eastern and western regions have continued to lead the nation in terms of the total area dedicated to transport land. The expansion speed of transport land in the central and western regions, however, has been faster than in the eastern and northeast regions. As for PCTLA, the western region had the greatest amount and the central region the least. Further, PCTLA showed significant spatial autocorrelation. Economic development, government regulations, industrial structure, and the extent of opening up and urbanization had significant positive impacts on PCTLA, while the development of railway freight had a negative impact. This paper concludes with some policy suggestions for optimizing transport investment, accelerating the adjustment of industrial structure and transport structure, and implementing high-quality urbanization. The results should be of interest to those involved in the sustainable development of transport systems.

Vibration energy harvesting system based on track energy-recycling technology for heavy-duty freight railroads

To ensure the efficient and safe operation of train transportation systems, the track vibration resulting from train movement can be utilized to power the sensors for intelligent applications. This paper presents a vibration energy harvesting system based on track energy-recycling technology for heavy-duty freight railroads. The energy-recycling system includes a vibration conversion module, a generator module and a power storage module. The irregular vertical vibrations produced by contact between the wheel and railroad are considered. The vibration conversion module converts the reciprocating vertical displacement into a one-way rotation through a scissor linkage and slider mechanism. A three-phase generator is coupled with an energy conversion module shaft and generates a three-phase direct current. Then, after rectification and filtering, the electricity is stored in the supercapacitors. Theoretical analysis, dynamic model analysis and mechanical simulation verify the dynamic response of the system under input excitation. Furthermore, mechanical testing and sensing (MTS) machine tests yield a 73.38% maximum mechanical efficiency with a 7.44 W peak power. Moreover, the charging tests of the proposed system with a supercapacitor indicate that the proposed system is suitable for self-powered sensors in railroads.

Strategies to Develop the Use of 4R Intermodality as a Combination of Rail Motorways and Motorways of the Sea

This paper introduces the concept of R4 (road-rail-ro-ro), a concept increasingly used in transport and logistics research circles that defines the modern concept of the transport chain as it passes through the intermodal use of rail, road, and ship via ro-ro. The integration of the new rail-road freight services into the reference supply model allows us to define the supply model for the design scenario on which the evaluation is now focused in terms of service-mode demand shares and in terms of design network flows and performance indicators carried out by demand-supply interaction models applied to all available service-modes. The use of strength-weaknesses-opportunities-threats analysis (SWOT) allows for the identification of some strategies to enhance and improve the current rail and maritime corridors in order to attract more customers using the different services, ultimately triggering the involvement of more actors in generating bigger and better integrated logistic chains using intermodality. The SWOT analysis allows the identification of a series of measures in order to adapt, maintain, enhance or exploit the aspects arising from the expert analysis.

Research on Differential Pricing and Train Operation Decisions for Railway Cargo Transportation Under Competitive Conditions

Railway freight operations aim not only to market themselves aggressively to capture the market in a competitive environment but also to achieve refined management. The operational decisions chosen by carriers can have a significant impact on the revenue across freight services. Nowadays, various forms of transported products, train make-up, and schedules are developed from the perspective of production convenience, with less consideration of shippers’ needs for the time utility, frequency, and tariffs of transportation services. This paper investigates a joint optimization approach to railroad operation planning that combines meeting the transport demand preferences of different shippers in a competitive environment. Considering the heterogeneity of shippers’ transportation demands and the competitive environment with freight trucking, a new bi-level programming model is proposed that incorporates pricing decisions and operational planning policies, such as car blocking, train routing, and make-up. An exact solution for this model is developed by adding valid inequalities to the mixed-integer formula and the experiment is conducted with data from bulk coal cargo transportation of the S Railway Bureau Group Corp. A simple transportation network is presented, and the calculation results of the pricing decisions that maximize the profit in each operation decision in this network are reported.

Reliability Assessment Model and Simulation of Journal Bearing of Railway Freight Cars Based on Bayesian Method under Small Sample Sizes

Generally, the box bearing of railway freight cars has no bearing sample failure data at the end of the time-terminated reliability test. However, it is expensive and has high service reliability requirements. Given a small sample size and zero-failure data, the traditional failure probability calculation formula based on a large sample size and the reliability modeling technique cannot easily assess the reliability of rolling bearings accurately. Considering the applicability of the bearing of railway freight cars, this study integrated the prior information of samples and the simulation test information according to Bayes statistical theory, deduced the mathematical model of cumulative failure probability under failure-free data, calculated the distribution parameters using the least square method, and established the reliability estimation model of rolling bearings on the basis of Weibull distribution. The failure-free simulation data of rolling bearings were produced according to the Monte Carlo simulation, and the reliability of the journal bearing of railway freight cars was simulated and assessed by three methods. Simulation results demonstrate that the proposed reliable Bayes multilayer estimation method could not only meet the design requirements of the ISO 281 rolling bearing standards on that basis of the failure-free data and small sample size of the time-terminated simulation, but also assess the reliability of the rolling bearing of railway freight cars.

Comparing the Efficiency and Effectiveness of Different Train-Following Control Algorithms for Fleets of Heavy-Haul Freight Trains under Moving Blocks

With the nationwide installation of positive train control (PTC) technology recently completed, freight railroads are searching for ways to leverage the technology to improve their operations beyond increasing safety. One possibility is reducing train headways through developing and installing a PTC-based moving-block system, thus increasing the capacity of railroad mainlines without adding costly track infrastructure. Though operating trains at shorter headways can theoretically increase line capacity, effectively controlling following trains becomes more difficult compared with a fixed-block system, requiring a fast-reacting train crew or control algorithm that effectively minimizes headway and fuel consumption while attenuating all fluctuations in lead-train speed. Otherwise, rapid changes in throttle and brake settings may be required, reducing following-train fuel efficiency, generating in-train forces, and diminishing the expected capacity gains from shortened headways. This research, sponsored by the Federal Railroad Administration, aims to better understand how closely following freight trains respond to different throttle- and brake-control algorithms. Using insights from connected automobile and truck platooning technology, the project team developed several train-following control algorithms, analyzed their stability, and simulated their performance with fleets of freight trains subject to different speed profiles. While moving-block systems do require additional train spacing beyond the minimum safe braking distance to account for train control actions, effective train-following control algorithms can minimize this distance. Also, the developed control laws exhibit a trade-off between minimizing train headway and fuel consumption, potentially allowing railway operators to choose an optimal balance.

Innovative, Scientific and Technological Priorities of Railway Freight Transport

Seven main priorities for development of rail cargo transportation are emerging in the context of an active intensification of scientific and technological development cycles, widespread digitalisation of business processes and an increase in competition in the transport industry. A key element of increasing the attractiveness of rail cargo transportation is its innovative, scientific, and technological development, especially in terms of increasing customer focus. Today, the principles of customer focus in the field of railway transportation of goods are among core factors in competitiveness of railway carriers. This issue is particularly relevant for the Russian Federation that owns a high potential for development of transit routes thanks to its advantageous geographic location. This fact determines attractiveness of railway transportation for cargo haulage customers. The image of future scientific and technological development of railway cargo traffic is formed under the influence of such trends as development of heavy-haul rail traffic, international container transportation, proactive introduction of digital technologies for interacting with customers and monitoring the condition of rolling stock, the provision of services within a single transport and information space, increase in margins and environmental safety of transportation. Digital transformation of the transportation process is among high priorities, which is explained through the importance of maintaining safety of transportation, increasing the transit capacity of the railway network and development of an integrated system for ensuring openness of data to provide customers with all the necessary information. Another priority area serves to increase the economic efficiency of cargo traffic by achieving growth in the share of high-margin goods. Such goods may include pharmaceutical and perishable products, information and communication, electronic and radio-electronic products, etc. An increase in the share of such transportation with a decrease in the volume of coal/oil transportation also has a positive effect on external appearance of the railway company for external investors. The image of the future of rail cargo transportation is largely dependent on various external and internal factors having effect on the industry. Besides, it depends on the emerging macro-trends in the global economy, which determine a certain vector for development of the railway industry. The study, to achieve its purposes, has widely used qualitative research methods and bibliometric analysis of scientific literature, international strategic and program documents of the industry and its companies.

Determining the strained state of prefabricated metal corrugated structures of a tunnel overpass exposed to the dynamic loading from railroad rolling stock

This paper reports the analysis of prospects for the use of prefabricated metal corrugated structures in the body of the embankment of a railroad track in the form of a tunnel overpass in order to pass road vehicles and railroad rolling stock. A technique of inertial dynamic tests of the deformed state of a tunnel overpass from prefabricated metal corrugated structures during the passage of railroad rolling stock is given, by measuring accelerations at the top and on the sides of overpass structures. An algorithm is proposed for processing the acceleration signal for assessing the strained state of metal corrugated structures of a tunnel overpass under the action of dynamic load from railroad transport. Experimental dynamic measurements of accelerations arising at the top and on the sides of a tunnel overpass during the passage of passenger and freight railroad rolling stock were carried out. The maximum value of accelerations arising at the top of a tunnel overpass during the passage of a freight train was 7.99 m/s2, and when passing a passenger train – 6.21 m/s2; the maximum accelerations that occur on the sides were 2.63 m/s2 and 1.77 m/s2. It is established that the maximum deformations of metal corrugated structures of the top of a tunnel overpass, when passing freight and passenger trains are, respectively, 1.63 mm and 1.11 mm. The maximum strains of metal corrugated structures on the sides of an overpass are 1.07 mm and 0.48 mm. The value of relative deformations in the vertical and horizontal dimensions of the structures of a tunnel overpass under the action of dynamic loads from the railroad rolling stock has been found. The relative vertical strains of an overpass amounted to 0.020 %; horizontal – 0.012 %. The practical significance of this work is that with the help of the devised procedure for measuring accelerations, it is possible to assess the strained state of metal corrugated structures under the influence of dynamic loads from the railroad rolling stock

A bridge weigh-in-motion algorithm for fast-passing railway freight vehicles considering bridge-vehicle interaction

Accurate weight information of freight vehicles is of great value for the assessment and maintenance of railway infrastructures. Existing bridge weigh-in-motion (BWIM) methods can introduce errors when the vehicle speed is high so that the dynamic effect cannot be filtered by signal processing. This paper proposes a novel BWIM algorithm for fast-passing railway freight vehicles, in which the dynamic coupling of the VB system is utilized. An extended state-space model with unknown mass parameters for the time-dependent VB system is established. Based on the model, an SPKF algorithm with a high convergence rate for identifying the mass parameters is proposed. Numerical examples of freight vehicles passing a 40 m railway bridge with a speed up to 120 km/h are presented to validate the effectiveness of the proposed algorithm.

Comprehensive analysis of the modern rolling stock efficiency in bulk cargo transportation

Introduction. Under the conditions of increasing containerisation of railway freight traffific, the problem of fifinding new cargo flflows suitable for transportation of freight containers or other types of intermodal freight containers on acceptable terms for both the carrier and the consignor is becoming increasingly important. Being of a fifixed size, large-capacity containers can not always meet the demands of consignors due to insuffificient carrying capacity, body volume and tariff conditions. The article examines the technical and economic effificiency of railway transport using various types of rolling stock and corresponding logistics technologies in the search for new areas for containerisation of cargo flflows.Materials and methods. Using bulk transportation, which is weakly subject to containerisation, as example, the authors carried out an analysis of the effificiency of rolling stock depending on the type of transported bulk freight (freight density). The comparison was performed both between common types of rolling stock (conventional and increased axle load gondola) and rather rarely used types of rolling stock (articulated gondola with increased axle load, demountable railway body, open top containers and specialised bulk containers).Results. Graphs have been plotted showing the effificiency of using each type of rolling stock, expressed through the volume of transported freight per running meter of the car and through the use of the useful volume of the rolling stock itself. The comparison proved, fifirstly, the obvious thesis about the better suitability of gondola cars for the transportation of bulk freight, and secondly, it showed a signifificant deterioration in the bulk freight transportation conditions for largecapacity containers.Discussion and conclusion. The innovative system of demountable railway bodies demonstrates average results in the overall ranking, which indicates suffificient potential for the implementation of this logistics technology.

Research on China's High-speed Railway Development from the Perspective of Financial Analysis and Management

Over the years, the number of railway passengers sent, the turnover of railway passengers, freight volume, cargo turnover, and conversion turnover have steadily ranked first in the world. By the end of 2020, China had 146,000 kilometers of railways in operation, 38,000 kilometers of which were High-speed railways, ranking first in the world. However, behind these honours, there is a practical problem of low profits and high liabilities of High-speed rail projects. This paper will be based on the perspective of financial analysis, analyse financial system of the connotation of health management, from the profitability, asset quality, debt conditions, operating four aspects to build High-speed railway financial health management system, The corresponding indexes are obtained through quantitative analysis to evaluate the current operation status of High-speed railway.

Topological Approach for Optimizing Railroad Freight Network Restoration after Disruptions

A topology-based method is proposed for optimizing the restoration sequence of damaged components in a disrupted rail freight network. Formulated as a demand-weighted average of reciprocal shortest path lengths, network efficiency is used as an indicator of overall connectivity for origin–destination (OD) pairs having freight demand. With the fixed demand matrix, a given network configuration, and a given disruption scenario, the cumulative loss of network efficiency during the restoration process is computed for each evaluated restoration sequence, using network efficiency values in intermediate network states as well as the duration of each restoration phase (i.e., restoration plus access time). This cumulative loss is treated as a measure of post-disruption network resilience, and is minimized with a simple genetic algorithm (GA) that finds the corresponding optimized restoration sequence, which also determines the optimized restoration schedule. The proposed method is demonstrated in a synthesized numerical case of a small network and a disruption scenario. The GA can find the globally optimal restoration sequence relatively fast, with its effectiveness further verified through exhaustive enumeration for three additional disruption scenarios. Sensitivity analysis results indicate that higher topological centrality and freight throughput of damaged nodes or disruption-induced isolation of some nodes are responsible for higher minimized loss of cumulative efficiency. The optimized restoration sequence tends to prioritize nodes and adjacent links with relatively high freight throughput in normal operation.

A hybrid approach for designing a railway transportation network of hazardous material tanks

This research proposes a design approach by hybrid optimization, which mainly includes the qualitative assessment and quantitative planning. In view of the multiple qualitative indicators in the location of tank handling stations, the fuzzy calibration is used to determine the ranking index of each candidate station. After that, these indices are integrated into the optimization model of a transportation network as weights. This bi-objective model is to minimize the total risk and the total operating cost. In order to verify the validity of the 0-1 quadratic programming model and the discrete characteristics of solution space, we propose a numerical algorithm. The process of the numerical algorithm is based on linearization conversion and the parallel branch & bound. For large-scale cases with a mass of variables and constraints, a heuristic is made, namely Pareto shuffled frog leaping algorithm. A case study is completed in the railway freight network in north China. This research can provide a theoretical basis and operating reference for railway transportation of hazardous materials.

Research on Site Selection of Changsha–Zhuzhou–Xiangtan Railway Logistics Center Based on Grey Wolf Optimization Algorithm

With the realization of China’s strategic concept of “The Belt and Road Initiative”, all countries have actively carried out the planning and construction of the Trans-Asian Railway Network, and railway freight has ushered in new development opportunities. As the core cities of Hunan, Changsha, Zhuzhou and Xiangtan also actively respond to the development trend of railway freight to logistics direction. In this paper, grey wolf optimization algorithm is used for the railway logistics center location in Changsha–Zhuzhou–Xiangtan. Some data of railway freight supply points and existing freight stations in this area are used for experimental simulation, so as to reduce the investment cost of the construction of railway logistics center and provide scientific decision-making basis.

A railcar re-blocking strategy via Mixed Integer Quadratic Programming

This article presents a novel solution namely Pre-blocking through Re-waybilling to minimize railcar cuts in freight railways. The Pre-blocking through Re-waybilling Problem (PRP) can be described as follows: A freight train carrying m railcars, loaded or empty, arrives at a local classification yard where, based on the destination on their electronic waybills, railcars will be physically switched to n outbound trains. Number of railcar cuts depends on the order of railcars on train. The objective is to minimize the number of railcar cuts by means of changing the electronic waybills of empty railcars, i.e. re-assignment of empty railcars to customers, while respecting supply, demand, and feasibility constraints. In order to solve this problem, a supply–demand network is constructed first, where supply nodes and demand nodes represent railcars and destinations, respectively. The problem is then formulated as a modified transportation problem. Unlike the conventional transportation problem, a linear arc cost function is proposed to describe the adjacent cars’ impact on railcar cut. The objective is converted to a quadratic function, leading to a Mixed-Integer Quadratic Programming (MIQP) problem. We improve proposed MIQP to a Convex Mixed-Integer Quadratic Programming (C-MIQP) problem by adding a quadratic term to the objective function. Illustrative and realistic examples are presented to validate the feasibility and efficiency of proposed pre-blocking optimizer.

Research on Multicriteria Decision-Making Scheme of High-Speed Railway Express Product Pricing and Slot Allocation under Competitive Conditions

Scientifically and reasonably pricing products and allocating slots are key to improving the profitability and competitiveness of high-speed railway expresses. In this research, we focus on the freight transportation pricing and slot allocation of high-speed railway express companies in a competitive environment. The goals of this research are to make decisions on the pricing and slot allocation schemes of the high-speed railway express between sections through the method of multicriteria decision making, and then to test these changes in reality. This research innovatively takes the high-speed freight Electric Multiple Unit (EMU) train as its research object and innovatively applies the revenue management theory to high-speed railway express research in a competitive environment, proposing a comprehensive decision-making model based on the sharing rate model. The results show that, by adopting the scheme proposed in this research, the income of high-speed railway express companies can be increased by 13.6%. In addition, the method proposed in this research also enriches the current theory on high-speed railway freight transportation, providing strategies for companies to expand their market and increase profit.

China's railway train speed, density and weight in developing

PurposeThis study aims to analyze the development direction of train speed, density and weight in China.Design/methodology/approachThe development of China's railway in the past 40 years can be divided into 3 stages. At the stage of potential tapping and capacity expansion, it is important to improve the train weight and density by upgrading the existing lines, and improving transportation capacity rapidly. At the stage of railway speed increase, the first priority is to increase train speed, reduce the travel time of passenger train, and synchronously take into account the increase of train density and weight. At the stage of developing high-speed railway, train speed, density and weight are co-developing on demand.FindingsThe train speed of high-speed railway will be 400 km h−1, the interval time of train tracking will be 3 min, and the traffic density will be more than 190 pairs per day. The running speed of high-speed freight EMU will reach 200 km h−1 and above. The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h−1. The minimum interval time of train tracking can be compressed to 5 min. The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t. EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service. Small formation trains will operate more in intercity railway, suburban railway and short-distance passenger transportation.Originality/valueThe research can provide new connotations and requirements of railway train speed, density and weight in the new railway stage.

Connectedness Efficiency Analysis of Weighted U.S. Freight Railroad Networks

Abstract Freight rail networks serve a key role in transporting bulk goods to accommodate changing market demands and to serve public needs. Network analyses of such systems can provide important insights into enhancing transportation efficiency and system resilience. This paper develops and investigates a topological analysis model for network efficiency, which is associated with the connectedness of a network's nodes by its links and their corresponding network attributes. This model allows analyzing network topologies with or without assigned weights to their nodes and links based on different attributes. Key attributes may include physical length of links, commodity types and volume of goods transported through links, and dwell-time at nodes, and origination termination volumes of goods, types of goods moved, and origins and destination of goods. The model presented here enables (1) defining distinctions that may be employed for the assignment of node and link weights, (2) gaining an understanding of node and link criticality, and (3) providing methods for objectively maintaining and enhancing network performance. Such analyses can inform rail managers and executives in planning expansions, route or freight changes, or preparations for potential node or link failures. A case study of an aggregate U.S. freight rail network along with other example topologies is presented to demonstrate the use of selected network attributes and their influence on connectedness efficiency and the impacts of node and link failures on the overall transport efficiency.