Railway Research Articles

Low-Carbon Water–Rail–Road Multimodal Routing Problem with Hard Time Windows for Time-Sensitive Goods Under Uncertainty: A Chance-Constrained Programming Approach

In this study, a low-carbon freight routing problem for time-sensitive goods is investigated in the context of water–rail–road multimodal transportation. To enhance the on-time transportation of time-sensitive goods, hard time windows are employed to regulate both pickup and delivery services at the start and end of their transportation. The uncertainty of both the demand for time-sensitive goods and the capacity of the transportation network are modeled using L-R triangular fuzzy numbers in the routing process to make the advanced routing more feasible in the actual transportation. Based on the carbon tax policy, a fuzzy linear optimization model is established to address the proposed problem, and an equivalent chance-constrained programming formulation is then obtained to make the solution to the problem attainable. A numerical experiment is carried out to verify the feasibility of incorporating the carbon tax policy, uncertainty, and water–rail–road multimodal transportation to optimize the low-carbon freight routing problem for time-sensitive goods. Furthermore, a multi-objective optimization is used to reveal that lowering the transportation costs, reducing the carbon emissions, and avoiding the risk are in conflict with each in the routing. We also analyze the sensitivity of the optimization results concerning the confidence level of the chance constraints and the uncertainty degree of the uncertain demand and capacity. Based on the numerical experiment, we draw several conclusions to help the shipper, receiver, and multimodal transportation operator to organize efficient water–rail–road multimodal transportation for time-sensitive goods.

Effective Bi-decoding networks for rail-surface defect detection by knowledge distillation

No-service rail-surface defect detection is a crucial method for assessing the quality of railroad tracks. However, the low-contrast and dark-tone characteristics of track-surface textures pose challenges to current defect-monitoring techniques. Real-time and on-site online inspections are important to ensure safe railway operation; however, most complex models for no-service inspections are difficult to deploy on mobile devices. To address these challenges and overcome the detection difficulties associated with complex scenes, we designed a knowledge distillation-based double decoding-layer refinement network (EBDNet-KD). The first decoding process is guided by a bimodal high-level semantic feature map obtained by extending the attention-based graph convolution to incrementally enhance the dual-stream features and obtain an image restoration prior. A divide-and-conquer decoder is then designed to distinguish features using different decoding layers. The prior is then used in the second decoding layer, which enables the bimodal features to interact fully and obtain the final prediction map. We introduce a knowledge distillation strategy that enables a lightweight, compact student network to learn a complex teacher network’s feature extraction process. This facilitates pixel-consistent learning of the knowledge within the bi-decoder layer, as well as bidirectional learning of the focused contextual response knowledge to optimize the model. The EBDNet-KD significantly reduces computational costs while guaranteeing performance with a parameter count of only 28 M. EBDNet-KD demonstrated superior performance over 15 state-of-the-art methods in experiments conducted on NEU RSDDS-AUG, an industrial RGB-depth dataset. We assessed the generalizability of EBDNet-KD by evaluating its performance on three additional public datasets, yielding competitive results. The source code and results can be found at https://github.com/Wuyue15/EBDNet.

Выбор функции зависимости вероятности появления остаточных деформаций от нагрузок при определении оптимальных возвышений наружного рельса в кривом участке пути

Purpose: the outer rail elevation in a curved section of railroad track according to the 2021 Guide for Determining the Elevation of the Outer Rail is determined by taking into account unmitigated accelerations, radii (permissible and admissible). Taking these indicators into account allows to determine the best values of outer rail elevations in terms of operational characteristics. But these elevations cannot be called optimal in terms of the amount of work performed during the current maintenance of the track in curves. To determine the optimal elevation, labor costs should be considered throughout the life cycle of the curved section. Since the occurrence of costs is mainly influenced by residual deformations during the life cycle, it was decided to consider the probability of residual deformations during the life cycle. Methods: the choice of the function of dependence of the probability of occurrence of residual deformations on loads was made on the basis o probability theory and regression analysis. The least squares method was used as a method of regression analysis. On its basis, functions with the greatest convergence relative to the function obtained using probability theory were selected. Results: the study found that dynamic loads generated during rolling stock movement on railway tracks follow a normal distribution function according to probability theory. Since certain dynamic loads during operation lead to residual deformations, the probability of such deformations can also be described using a normal distribution function. The resulting function for predicting the probability of residual deformations based on load factors was identified. Practical significance: the research findings can be used to determine the optimal elevation of the outer rail that minimizes labor costs during railway track operation

In-Motion, Non-Contact Detection of Ties and Ballasts on Railroad Tracks

This study aims to develop a robust and efficient system to identify ties and ballasts in motion using a variety of non-contact sensors mounted on a robotic rail cart. The sensors include distance LiDAR sensors and inductive proximity sensors for ferrous materials to collect data while traversing railroad tracks. Many existing tie/ballast health monitoring devices cannot be mounted on Hyrail vehicles for in-motion inspection due to their inability to filter out unwanted targets (i.e., ties or ballasts). The system studied here addresses that limitation by exploring several approaches based on distance LiDAR sensors. The first approach is based on calculating the running standard deviation of the measured distance from LiDAR sensors to tie or ballast surfaces. The second approach uses machine learning (ML) methods that combine two primary algorithms (Logistic Regression and Decision Tree) and three preprocessing methods (six models in total). The results indicate that the optimal configuration for non-contact, in-motion differentiation of ties and ballasts is integrating two distance LiDAR sensors with a Decision Tree model. This configuration provides rapid, accurate, and robust tie/ballast differentiation. The study also facilitates further sensor and inspection research and development in railroad track maintenance.

CONSTRUCTION OF THE RAILWAY TRACK OF UKRAINE AND PROSPECTS FOR THEIR IMPROVEMENT

The goal. The process of improving the design of the railway track requires a detailed study of the history of the development of its structural elements, methods of combination, interconnections and limits of mutual influence. Modern track designs are the result of many years of hard work by scientists and long operational tests. Some designs were inventions at the time, some were breakthrough technologies, some remained just ideas, and some have existed for more than a century. The study of the history of the development of railway track structures and modern existing structures in operation made it possible to identify a promising direction for improvement and further development, taking into account the existing problems on the mainline transport tracks and industrial enterprise tracks. Reinforced concrete sleepers and intermediate fasteners that allow for track gauge adjustment are the railroad track structure that should be improved in the coming years. Improving railroad track design is a continuous process in the development of rail transport. Recently, new track designs have been introduced on Ukrainian railways. As a rule, the problems of track facilities are first considered and technical tasks are formulated. Then, a public discussion is held in the scientific and practical environment and an appropriate development strategy is born. Such a strategy is reviewed and approved at scientific and technical meetings and specialized commissions. This article aims to identify promising areas for improving the track design and solving the problems of installing and operating a continuous track by analyzing existing designs and world experience of railways. Methods. Methods of scientific analysis and synthesis of track development design, methods of analytical geometry. Results. Based on the analysis of the history of the development of the railroad track structure and modern designs, a promising direction of improvement is proposed. A promising railroad track structure is defined as a reinforced concrete sleeper and fasteners capable of forming an adjustable track gauge of up to 1545 mm. At the same time, it is necessary that the new design has sufficient stability of the jointless track plates. Practical significance. The application of the proposed structure within small radius curves, provided that the results of trial operation and testing of the established procedure are positive, will reduce the operating costs associated with the current maintenance of the tracks, expand the scope of laying of the jointless track and use reinforced concrete sleepers in small radius curves at industrial enterprises.

Effective factors on Migration to Kerman City and Immigrants’ Problems Using Analytical Hierarchy Process Model and Technique for Order of Preference by Similarity to Ideal Solution

Introduction: Marginal immigrants cause many problems in economic, social and cultural, physical ,and environmental aspects of cities. This study aims to investigate the factors affecting migration to Kerman city and the problems of marginalized immigrants using the analytical hierarchy process (AHP) and technique for order of preference by similarity to ideal solution (TOPSIS) models. Methods: This cross-sectional study was conducted in 2022, with a sample size of 147 households selected from Kerman suburban region. The data were collected by a standardized questionnaire measuring effective factors on the migration and the checklist of the immigrant problems. Results: The most important immigration factors were economic, social, geographical, political, educational and religious-cultural factors, respectively. Among 37 components studied, transferring the job of the family man as the family head, being on the main land, air and rail ways, having a special position at the international level, burying the family’s dead members in the desired city, and the education of the wife or one of the children of the family were the most important components. According to the results, more than 90% did not have access to public baths, sports facilities, government centers, private institutions, and parks, and recreational spaces. Conclusion: According to AHP model, economic factors ,and then social factors, were the most important reasons for migrating to the suburbs of Kerman. Therefore, it is suggested to create stable and long-term job opportunities , improve employment and business environment in the cities, and develop infrastructure to control migration to the city capitals.

Automatyczna diagnostyka elementów toru kolejowego z użyciem sieci neuronowych głębokiego uczenia

The article discusses a method for automatic diagnostics of a railway track. It consists in automatic evaluation of the technical condition of selected track elements, such as rails, wooden and concrete sleepers, fasteners and turnouts. It was carried out on the basis of analysis of video images of railroad track elements recorded by two line cameras placed on the diagnostic carriage. The selected FCN-8 deep learning neural network was used to assess the technical condition of the surveyed elements, and the effectiveness of the applied algorithm was determined on the basis of such measures as IoU, Precision, Recall. Conclusions on the application of the FCN-8 network in the automatic classification of features of selected railroad track elements are presented. The results obtained were compared with other methods used in vision diagnostics.

Microcontroller-based track axle counter system design

Abstract Axle counting technology is an extremely important part of many aspects in ensuring the safety of railroad operation. Axle counting equipment is set up on the railroad tracks, and through the operation of sensors, it detects the trains that drive into the train operating area where the axle counting equipment is arranged. A common axle counting system uses a detection device that utilizes a wheel sensor that senses the movement of the wheel cutting through magnetic lines of inductance causing a change in the magnetic field within the zone. This paper introduces a track axle counter system, the system will be a microcontroller as the core, the use of ultrasonic detection in the train interval of the train wheel distance changes, instead of the existing axle counting system using wheel sensors to sense the electromagnetic signals generated by the wheels, to achieve the axle counting and counting function, so as to determine the track occupancy.

Kinerja Angkutan Barang pada jalur Kereta Api di Sumatera Selatan

The study aims to determine the impact of the infrastructure and maintenance quality on On Time Performance to the company’s freight transportation railroad track performance in South Sumatra. The data of the research was collected from a population of 30 coal mining companies operating in the southern part of Sumatra. This research used Path Analysis as the data analysis techniques. The conclusion states that there is a significant positive direct and indirect influence of the infrastructure facilities and maintenance quality variable on the company’s goods transportation performance through OTP. In addition, the company’s freight transportation performance contributes directly to OTP. Based on the research findings, the company’s freight transportation performance can be maximized by improving the rolling stocks quality and maintenance through On Time Performance. The Path Analysis results show that the infrastructure maintenance directly contributes to OTP of 21.17 percent and contributes to the freight transportation performance of 17.04 percent.

Concept of Thermal Shrinkage-Resistant Railroad Rail for Use in Continuous Welded Rail Track

This paper presents the concept of a modified 60E1 rail dedicated to continuous welded rail (CWR) track. The presented solution is the subject of a patent application by the authors of the publication. The paper describes problems associated with the operation of CWR track and the phenomena of so-called “rail stressing”, i.e., stresses created in the rail due to thermal shrinkage that, in extreme cases, can lead to the buckling of the rail track. Simulation calculations of longitudinal track loads to represent the occurrence of thermal force as a result of the occurrence of high air temperatures were carried out for the constructed conventional model of the railroad track as well as the track with the proposed solutions. A discussion of the simulation results is presented, indicating the possibility for the wider application of both varieties of modified rail.

Design and Operational Assessment of a Railroad Track Robot for Railcar Undercarriage Condition Inspection

Design and Operational Assessment of a Railroad Track Robot for Railcar Undercarriage Condition Inspection

Effects of Austempering Temperature on the Corrosion Behavior of Fe – Ni Bainitic Steel with Al Addition for Railroad Tracks

Effects of Austempering Temperature on the Corrosion Behavior of Fe – Ni Bainitic Steel with Al Addition for Railroad Tracks

Bukovyna as part of the Austro-Hungarian Empire and its socio-economic development on the eve of rail way construction

This article examines how the socio-economic conditions in Bukovyna influenced the formation and development of the railway network in the region. It explores whether these processes aligned with the global trends of the time. Based on the analysis of scientific literature, memoirs, and archival materials, it was found that the topic of the formation and functioning of the railway network in Bukovyna had not been systematically studied. It was revealed that the Austrian authorities, by turning Bukovyna into an internal colony of the Habsburg Empire, kept the region in the position of a raw material appendage and a market for the industry of the empire's central provinces. The tariff, customs, credit, and tax systems introduced by the imperial government supported this process, acting in the interests of Austro-Hungarian capital. The development of the railway network was aimed at ensuring the economic interests of the empire, which affected the socio-economic development of Bukovyna. In particular, the construction of railways improved the transport infrastructure, leading to increased trade and higher volumes of raw material and goods transportation. However, this development had a dual nature. On one hand, it promoted economic growth and modernization of the region, but on the other hand, it intensified Bukovyna's dependence on the central provinces of the empire, limiting its economic autonomy and the development of local industry. The article also analyzes the impact of railway construction on the social aspects of life in Bukovyna. The railway became an important factor in migration, contributing to urbanization and the growth of the working class. However, at the same time, social tensions increased due to the unequal distribution of economic benefits and the intensification of local population exploitation. The conclusions of the article emphasize the need for further research to fully understand the impact of railway development on Bukovyna in the context of the Austro-Hungarian Empire and to compare these processes with similar developments in other parts of the world.

Time series anomaly detection using generative adversarial network discriminators and density estimation for infrastructure systems

Efficient data-driven defect detection techniques are crucial for maintaining service quality and providing early warnings for infrastructure systems. To this end, we proposed an effective unsupervised anomaly detection framework (DEGAN) using Generative Adversarial Networks (GANs). The framework relies solely on normal time series data as input to train well-configured discriminators into standalone anomaly predictors by leveraging repeatedly collected data from an infrastructure system. Expected normal patterns in data are identified by generators, and well-configured discriminators are extracted to evaluate anomalies in unseen time series. Kernel density estimation (KDE) is coupled with discriminators for probabilistic anomaly detection. Through a Class I railroad track case study, we evaluated the performance of a convolutional DEGAN in detecting anomalies identified by operators, achieving recall and precision of 80% and 86%, respectively. We also investigated the influence of GAN architectures and parameters, model validation scheme (supervised vs. unsupervised), clustering, and the KDE parameters.

Simulation of Stress Intensity Factor and J-Integral on UIC 54 Railway Failure Using A Fracture Mechanics Approach

Repeated loading on the railroad tracks will result in fatigue failure. Fatigue failure combined with a defect in the form of a crack in the railroad track will result in a decrease in strength. Defects in the form of cracks are formed due to improper manufacturing and treatment processes. One treatment that can cause the formation of defects in the form of cracks is thermite welding. Improper and non-standard thermite welding techniques can trigger the formation of defects in the form of cracks in the railroad joints. Based on these problems, this simulation aims to obtain information about the value of maximum stress, SIF, J-Intergal, number of cycles, and crack extension from variations in crack size to repeated loading. The method consists of preprocessing, processing and postprocessing. Preprocessing begins with the design of the UIC 54 railroad crack which consists of 3 variations of crack length, namely 10 mm, 15 mm, and 20 mm. The design was tested through static structural simulation using the ANSYS 2021 R2 application. Meshing is configured using an element size of 5 mm and uses curvature capture. The results of the simulation obtained maximum stress values, SIF, J-Integral, number of cycles, and crack extension. Based on the simulation of SIF 1 and J-Integral values on the specimen design with a crack length of 10 mm it shows 362.03 Mpa.mm1/2 of 0.5708 mJ/mm2, for an initial crack length of 15 mm that is equal to 482.81 Mpa.mm1/2 and 0.91738 mJ/mm2, and for an initial crack length of 20 mm, it is 600.54 Mpa.mm1/2 and 1.4465 mJ/mm2. The results show that the increase in SIF 1 and J-Integral will be proportional to the increase in the initial crack length value. .

Influence of wagon body flexural deformation on the indicators of interaction with the railroad track

Influence of wagon body flexural deformation on the indicators of interaction with the railroad track

Level of Service Criteria of Rail Road Grade Crossing Based on the Perceptions of Motorist and Non-motorist

Level of Service Criteria of Rail Road Grade Crossing Based on the Perceptions of Motorist and Non-motorist

Analysis of the Direction and Prediction of Built-Up Land Development in Slawi Sub-district, Tegal Regency, Indonesia in 2045

Abstract Slawi Sub-district is characterized by a high population density as it serves as both the capital of Tegal Regency and the central hub of the Tegal Regency government. The large growth of built-up land threatens the balance of the environment and uncontrolled spatial planning. This study aims to predict the development of built-up land in Slawi Subdistrict in 2045 and determine the direction of built-up land development in Slawi Subdistrict in 2007, 2015, 2023, and 2045. The research approach used Geographic Information System with the prediction of Cellular Automata (CA) Markov Chain prediction model. The inputs of the CA Markov model are the driving factors of land cover change consisting of road network, river network, government, settlement, and slope. The results showed that in 2045 the predicted built-up land area was 1,111.72 ha or 71.41% of the total land cover. The development of built-up land in Slawi Sub-district is closely related to the road distribution pattern, where the north and south are influenced by arterial road and rail road, while the east and west are influenced by collector roads.

Static and Dynamic Strain in the 1886 Charleston, South Carolina, Earthquake

ABSTRACT During the 1886 Mw 7.3 Charleston, South Carolina, earthquake, three railroads emanating from the city were exposed to severe shaking. Expansion joints in segmented railroad tracks are designed to allow railroad infrastructure to withstand a few parts in 10,000 of thermoelastic strain. We show that, in 1886, transient contractions exceeding this limiting value buckled rails, and transient extensions pulled rails apart. Calculated values for dynamic strain in the meizoseismal region are in reasonable agreement with those anticipated from the relation between strain and moment magnitude proposed by Barbour et al. (2021) and exceed estimated tectonic strain released by the earthquake by an order of magnitude. Almost all of the documented disturbances of railroad lines, including evidence for shortening of the rails, can thus be ascribed to the effects of dynamic strain changes, not static strain. Little or no damage to railroads was reported outside the estimated 10−4 dynamic strain contour. The correspondence between 10−3 and 2×10−4 contours of dynamic strain and Mercalli intensity 9 and 8, anticipated from the dependence of each quantity on peak ground velocity, suggests it may be possible to use railroad damage to quantitatively estimate shaking intensity. At one location, near Rantowles, ≈20 km west of Charleston, a photograph of buckled track taken one day after the earthquake has been cited as evidence for shallow dextral slip and has long focused a search for a causal fault in this region. Photogrammetric analysis reveals that the buckle was caused by transient contraction of <10 cm with no dextral offset. Our results further weaken the evidence for faulting in the swamps and forests south of the Ashley River in 1886, hitherto motivated by the photograph and limited macroseismic evidence for high-intensity shaking.

Naming the Zones of Sexual Commerce

Abstract This article examines the historical origins of the term red-light district. It argues that red lights became associated with prostitution in the United States not only because of red’s popularity in the decor of nighttime businesses but also because of color symbolism popularized by the transportation revolution. As red signal lights on railroads came to indicate “stop—danger,” people accustomed to viewing prostitution as a moral and physical threat read that symbolism onto nighttime businesses’ existing practices of display. Meanwhile, places of prostitution that were located near railroad tracks in the American West embraced the red light as a form of advertising. The red light’s simultaneous status as a lure and warning captured ambivalent responses to prostitution. As a result, it became a potent symbol of late nineteenth-century efforts to keep the sex trade at arm’s length while also treating it as ineradicable. When city officials tried to control the harms of prostitution by segregating it, the products of their efforts came to be known as “red-light districts.” Although the term has in some ways transcended its roots, scholars should be conscientious about their use of it given its implicit moralization of both the sex trade and urban space.