Railway Freight Research Articles

МЕТОДИКА УТОЧНЕНИЯ МНОЖЕСТВА ПАРЕТО НА ОСНОВЕ УЧЕТА СТОХАСТИЧНОСТИ КРИТЕРИАЛЬНЫХ ФУНКЦИЙ

Selection of rational structural and technological parameters of railway transport objects is an important task in the sphere of operations control. The analysis of theory and practice showed that the selection of structural and technological parameters is carried out with insufficient accuracy and can lead to irrational decisions. In order to increase quality of decisions aimed at development of infrastructure and technology of railway stations the authors propose to use a bicriterial approach. For the decrease of negative subsequences and a risk of making irrational decisions the authors suggest a method for clarification of a Pareto set on the basis of consideration for stochasticity of criterial functions. The method includes the following steps: calculation of confidence interval for assessment of mathematical expectation, correlation analysis, construction of scattering ellipses and single-factor variance analysis. In order to confirm the efficiency of the suggested method the paper presents results of selection of the most rational variant for the increase of estimated capacity of a freight railway station.

Evaluation of interoperability to Ukrainian tank cars, as they are recognized for the transportation of non-healthy cargoes by railway transport

Ensuring safety during the transportation of goods by railway transport with the minimization of the level of risks is a priority task today. An analysis was made that shows that in Ukraine there are significant developments in the field of improving the design of wagons, their dynamic characteristics and safety. Manufacturers of railway cars strive to increase the number of new, high-quality and technically advanced (under the terms of interoperability) railway rolling stock in use. 11 interoperability specifications were considered: infrastructure; energy; management; noise; persons with limited mobility; safety in tunnels; freight cars; locomotives, passenger cars and rolling stock; freight transportation telematics; passenger transportation telematics; the movement of trains that are approved and currently in operation. The considered requirements and components of the Technical Certification of Interoperability and domestic normative documents for railway cars, namely: the requirements of the Technical Certification of Interoperability for freight railway cars; requirements of regulatory documents in Ukraine regarding tank cars; technical characteristics of tank cars produced in Ukraine. A comparative analysis was made of the conformity of the general technical parameters of tank cars manufactured in Ukraine, the principle of operation and design of brake systems of freight cars, the conformity of the dimensions of tank cars, regarding the determination of the dimensions of railway rolling stock (or the dimensions of rolling stock), the fulfillment of conditions under which it is possible the east of the rolling stock. Calculations were made for an empty car in the presence of a raised outer rail, as well as calculations of traffic safety criteria according to these standards. Taking into account the requirements for the production of modern rolling stock is a necessity, which is considered on the example of tank cars, which are currently produced for compliance with interoperability requirements, and the proposed priority measures to achieve the specified compliance

Модель результативного ринку і технологія вантажних залізничних перевезень

The processes of liberalization, the attempt to transition the railway industry to a new market model of free competition without corresponding changes in the component model negatively affect the efficiency of the railway industry and the effectiveness of the freight railway service market. It is proposed to look at the problem not from the standpoint of changing the form of ownership in the industry and the formation of a free competition market, but from the standpoint of finding a balance between the work technology and the model of the freight rail transport market that is being used. The study is based on the well-known concept of Industrial organization. The author considers the market as a living mechanism that responds to changes in its components within its field, not only as a place for concluding deals. The effectiveness of the rail freight transport market largely depends on the technology of creating a rail freight service. It is proposed to form a market model based not so much on the appearance of competition, but on some harmony of the technology of freight railway service and the market, or rather the balance of the components of the service market. The goal is to define a model of an effective rail freight market, in which the railway industry will be able to show maximum efficiency. Work methods – expert assessment of an attempt to change the model of the freight rail transportation market; analysis of the reasons for the imbalance of the economic mechanism of transport activity in the field of freight rail transport; an attempt to structure the goals of an efficient rail freight market. Based on the results of the research, recommendations can be formulated regarding the formation of a balanced model of the market for freight rail transportation and the adjustment of goals and the existing market model.

Simulation study on carbon emission of China's freight system under the target of carbon peaking

The development of Chinese society needs the support of a perfect and efficient freight transport system. Nonetheless, China's freight system is facing a major challenge in reducing carbon emissions. Hence, firstly, this paper explores three major internal drivers of carbon emissions by analyzing the current situation in China's freight system: proportion of railway freight (PORF), railway electrification level (REL) and electric truck penetration (ETP). Secondly, the system dynamics (SDs) model is used to simulate the carbon emission system of freight transportation in China. Thirdly, this paper sets 13 scenarios of carbon peaking to explore the paths of carbon peaking before 2030 under the three levels of development of ETP oriented freight system. The results indicate that when PORF, REL, and ETP reach 23.96% of total freight volume, 83.7% of rail freight, and 11% of truck freight in 2030 respectively, China's freight system has the most optimistic scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2024, and the peak value is 0.842 billion tons. When PORF, REL, and ETP reach 15.96% of total freight volume, 63.7% of rail freight, and 3% of truck freight in 2030 respectively, China's freight system has the worst scenario of carbon peaking. Meanwhile, the time of carbon peaking is 2029, and the peak value is 1.016 billion tons. Also, it is proved that improving PORF, REL, and ETP is an effective way to achieve green and sustainable development of China's freight industry.

ВПЛИВ ПІДВИЩЕННЯ ВАНТАЖНИХ ЗАЛІЗНИЧНИХ ТАРИФІВ НА НАЦІОНАЛЬНУ ЕКОНОМІКУ

На основі світового досвіду обґрунтовано необхідність удосконалення аналізу регуляторного впливу нормативно-правових актів, який є основним інструментом забезпечення якості державного регулювання. Протягом останніх років спостерігається тенденція до періодичного підвищення тарифів на вантажні залізничні перевезення у внутрішньому сполученні. Останнє підвищення затверджено відповідним Наказом Міністерства інфраструктури України від 11 серпня 2021 р., який відноситься до регуляторних актів, щодо яких обов'язковим є проведення аналізу регуляторного впливу відповідно до прийнятої на державному рівні Методики.Вітчизняна методика не передбачає оцінки впливу на національну економіку. Саме тому здійснено оцінку можливого впливу дії регуляторного акта на національну економіку відповідно до розробленого в ДУ «Інститут економіки та прогнозування НАН України» методичного підходу, сутність якого полягає в більш детальній та комплексній кількісній оцінці прямого впливу регулювання на сфери економічних інтересів як громадян, суб’єктів господарювання, держави, так і суспільства в цілому (національної економіки). Оцінку впливу підвищення тарифів вантажних залізничних перевезень на національну економіку було здійснено з двох позицій: можливого впливу на ВВП і на конкуренцію в межах транспортної системи України.Розраховано внесок АТ «Укрзалізниця» у ВВП України від підвищення вантажних залізничних тарифів. Доведено, що дія Наказу Міністерства інфраструктури України матиме вплив на внутрімодальну конкуренцію в межах транспортної системи України через перерозподіл вантажних перевезень, з одного боку, для деяких позакласних вантажів на користь автомобільного та річкового транспорту, а з іншого – для окремих вантажів 3-го тарифного класу на користь залізничного. Такий перерозподіл позитивно вплине на конкурентні позиції залізничного транспорту на внутрішньому ринку вантажних перевезень, оскільки втрата деяких позакласних вантажів, перевезення яких є нерентабельними, не матиме негативного впливу на залізницю.

Shared-use rail corridors: a comparison of institutional perspectives in the United States and the European Union

ABSTRACT This paper reviews existing literature to identify issues, challenges, and best practices associated with shared-use freight and passenger rail corridors. Specifically, this paper will compare and contrast shared-corridor practices from an institutional perspective in the United States and the European Union. These two regions were chosen because of their shared social, political, technological, and economic ties, their historical mixes of private and state railroad operations, and because of the significant contemporary differences in the role of rail in these two regions. That mix of similarities and differences clarifies important commonalities specific to freight and passenger railroads that may be applicable in other times and places. Best practices include planning for: capital investment, long-term time horizons, measurable incremental improvements, regional multi-modality, and mutual benefits between freight and passenger operations.

Model Updating of a Freight Wagon Based on Dynamic Tests under Different Loading Scenarios

This article presents an efficient methodology for the calibration of a numerical model of a Sgnss freight railway wagon based on experimental modal parameters, namely natural frequencies and mode shapes. Dynamic tests were performed for two distinct static loading configurations, tare weight and current operational overload, under demanding test conditions, particularly during an unloading operation of the train and without disturbing its tight operational schedule. These conditions impose restrictions to the tests, especially regarding the test duration, sensor positioning and system excitation. The experimental setups involve the use of several high-sensitivity accelerometers strategically distributed along with the vehicle platform and bogies in the vertical direction. The modal identification was performed with the application of the enhanced frequency-domain decomposition (EFDD) method, allowing the estimation of 10 natural frequencies and mode shapes associated with structural movements of the wagon platform, which in some cases are coupled with rigid body movements. A detailed 3D FE model of the freight wagon was developed including the platform, bogies, wheelsets, primary suspensions and wheel–rail interface. The model calibration was performed sequentially, first with the unloaded wagon model and then with the loaded wagon model, resorting to an iterative method based on a genetic algorithm. The calibration process allowed the obtainment of the optimal values of eight numerical parameters, including a double estimation of the vertical stiffness of the primary suspensions under the unloaded and loaded static configurations. The results demonstrate that the primary suspensions present an elastic/almost elastic behaviour. The comparison of experimental and numerical responses before and after calibration revealed significant improvements in the numerical models and a very good correlation between the experimental and numerical responses after calibration.

New-style Banks and The Agent Governance Strategies of the Beiyang Government: A Study on the History of the Development of China's Documentary Railway Billing Business in Modern Times

Under the "weak state" regime of modern China, it was difficult for the country’s modernization process to develop without the effective intervention of a centralized state. In the process of government governance, absorbing social organizations and civil forces as agents had proved to be an effective method. Beiyang government’s governance strategy of ‘using agents to regulate agents’ in the documentary railway billing business could be regarded as typical of the diversity of government management. Qing Dynasty, government departments were not directly responsible for railway freight for various reasons, instead, they allowed railway transshipment companies to act as agents for freight management. Then transshipment companies gradually became an obstacle to Beiyang government’s reform on freight transport. However, under the Republic of China, the new-style bank discovered a benign opportunity to develop documentary railway billing service and created a bottom-up institutional reform model. Through the service, the bank became the new agent for the supervision of the transshipment company, which not only regulated the operation, but also forced railroad bureaus in the Yangzi Delta to be primarily responsible for railway freight. The Central Ministry of Transportation of Beiyang Government decided to promote this agency governance model and billing service nationwide. Received 11th January 2021; Revised 2nd June 2021; Accepted 20th July 2021

Design method of worn rail grinding profile based on Frechet distance method

Due to the large volume and high running density of railway freight lines, rail deterioration occur frequently. Thus, it is necessary to grind the rail in time to improve the wheel-rail relationship. The profile data of the worn rail were measured at different measuring points in a section, and the Frechet distance method was adopted to analyze the data. The representative profile reflecting the overall condition of rail wear in this section is obtained. Combined with NURBS curve theory, a fitting algorithm in which the rail profile with certain discrete points was established. Taking the reduction of the amount of grinding material removed as the objective function, setting wheel-rail matching characteristics, and the reduction of rail wear as the constraint conditions, a calculation model for rail grinding profile was established. The dynamic characteristics of standard profile CN75 and g grinding profile OP75 were analyzed by the vehicle track dynamics model. The results showed that compared with the standard profile CN75, the amount of grinding material removed of the grinding profile OP75 is reduced by 44.7%, and the height reduction of the rail top is reduced by 0.39 mm. After [Formula: see text] km of running, the wear amounts of grinding profile OP75 is about 36.1%–36.5% less than that of standard profile CN75.In the small curve section, the derailment coefficient of grinding profile OP75 is reduced by 11.7% compared with that of standard profile CN75. The dynamic performance is improved. The grinding target profile has better dynamic characteristics and is beneficial to reduce wheel-rail wear.

Statistical Analysis of Spatial Network Characteristics in Relation to COVID-19 Transmission Risks in US Counties.

Since the pandemic of COVID-19 began in January 2020, the world has witnessed drastic social-economic changes. To harness the virus spread, several studies have been done to study contributing factors that are pertinent to COVID-19 transmission risks. However, little has been done to investigate how human activities on the spatial network are correlated to the virus transmission and spread. This paper performs a statistical analysis to examine interrelationships between spatial network characteristics and cumulative cases of COVID-19 in US counties. Specifically, both county-level transportation profiles (e.g., the total number of commute workers, route miles of freight railroad) and road network characteristics of US counties are considered. Then, the lasso regression model is utilized to identify a sparse set of significant variables that are sensitive to the response variable of COVID-19 cases. Finally, the fixed-effect model is built to capture the relationship between the selected set of predictors and the response variable. This work helps identify and determine salient features from spatial network characteristics and transportation profiles, thereby improving the understanding of COVID-19 spread dynamics. These significant variables can also be utilized to develop simulation models for the prediction of real-time positions of virus spread and the optimization of intervention strategies.

Robust Tactical Crew Scheduling Under Uncertain Demand

We analyze a tactical freight railway crew scheduling problem, when train drivers must be informed several weeks before operations about the start and end times and locations of their duties. Between informing the train drivers and start of operations, trip demand changes due to cancellations, new bookings, and reroutings of trains, which might result in mismatches between train driver capacity at a location and demand. We analyze an approach that incorporates uncertain trip demand as scenarios, such that the start and end times and locations of the duties of a crew schedule are recoverable robust against deviations in trip demand. We develop a column generation solution method that dynamically aggregates trips to duties and decomposes the subproblems into smaller, computationally tractable instances. Our model determines duty frames that cover duties in many scenarios, creating recoverable robust crew schedules. We test our model on three real data sets of a major European freight railway operator. Our results show that our schedules are considerably more recoverable robust than those of the nominal solution, resulting in smaller mismatches between train driver capacity and demand.

Effects of Incorporating Rail Transport into a Zero-Emission Urban Deliveries System: Application of Light Freight Railway (LFR) Electric Trains

This paper addresses the issue of incorporating rail transport into an urban delivery system. Its main purpose was to identify the possibilities of utilising rail transport in a Zero-emission Urban Delivery System (ZUDS) by applying Light Freight Railway (LFR) electric trains. The study applied the following research methods: literature review, observation, case study, and mathematical computations. In order to estimate the volume of transport external costs reduction resulting from shifting urban deliveries from road to rail transport in the city of Szczecin, the EU methodology was applied to specify the amounts of external costs generated by individual modes and means of transport. The research study showed that application of LFR electric trains makes it possible to significantly reduce external costs generated by transport. Moreover, this solution may have an impact on developing Clean Transport Zones (CTZs) and may also contribute to expansion of the ZUDS. The research study results also provide grounds to conclude that application of the LFR system makes it possible to reduce negative effects generated by Urban Freight Transport (UFT) and to achieve a coherent zero-emission system for handling cargo and passenger flows in cities, which consequently contributes to achieving electromobility goals in transport.

Analysis of Safety Requirements for Securing the Semi-Trailer Truck on the Intermodal Railway Wagon

The article presented the issue of securing semi-trailer trucks and trailers during their transport using intermodal railway wagons as a part of combined transport. This issue was analysed in different operational conditions related to loading level, cross-winds influence, inertia forces due to the emergency braking, and track curvature. According to general rules of loading and securing cargo, described in the internal and UIC regulations, the transported load should be positioned and secured with minimised risk of undesirable displacement or rolling over during transport. Basic analysis showed that adverse conditions such as strong winds or emergency braking may require adequate additional cargo protection. The lack thereof may result in a severe accident or damage to the transported vehicle or the nearby structures. The presented results for generic road and railway freight vehicles showed that the required anti-rollover torque for a semi-trailer mounted on the railway wagon platform may differ considerably (almost four times at the same maximum tested airflow speed) depending on the conditions related to aerodynamic and inertia influence. The potential weaknesses of the analysis relate to the impracticality of experimental tests for roll-over (or derailment) events under high levels of cross-wind, due to economic and safety reasons. The analysis can be extended in the future by including unsteady aerodynamic forces and a full-vehicle model based on the multi-body method for a specific design solution.

Determination of Mapping Relation between Wheel Polygonalisation and Wheel/Rail Contact Force for Railway Freight Wagon Using Dynamic Simulation

The polygonal wear around the wheel circumference could pose highly adverse influences on the wheel/rail interactions and thereby the performance of the vehicle system. In this study, the effects of wheel polygonalisation on the dynamic responses of a freight wagon are investigated through development and simulations of a comprehensive coupled vehicle-track dynamic model. The model integrates flexible ballasted track and wheelsets subsystem models so as to account for elastic deformations caused by impact loads induced by the wheel polygonalisation. Subsequently, the vehicles with low-order polygonal wear, whether in empty or loaded conditions, are simulated at different speeds considering different amplitudes and harmonic orders of the wheel polygonalisation and thus the mapping relation between wheel/rail impact force and wheel polygonalisation is obtained. The results reveal that the low-order wheel polygonalisation except 1st order and 3rd order can give rise to high-frequency impact loads at the wheel/rail interface and excite 1st-bend modes of the wheelset and “P2 resonance” leading to high-magnitude wheel/rail contact force at the corresponding speed.

Customized Approach to Greenhouse Gas Emissions Calculations in Railway Freight Transport

The topic of global warming is and will continue to be a crucial topic of this millennium. Freight transport, as a producer of greenhouse gas (hereinafter GHG) emissions, makes a significant contribution to the greenhouse effect. Large supply chains and large volumes of freight transport, which imply the production of significant volumes of GHG emissions, characterize the automotive industry (hereinafter AI). Thanks to these premises, it is necessary to seek and develop tools for reducing the volume of GHG emissions produced from the logistic activities of the AI, while maintaining the required level of logistic services. The assumptions for the calculation of GHG emissions from railway freight transport (hereinafter RFT) in the AI were identified through the use of semi-structured interviewing. Available railway freight GHG emission calculators were identified and analyzed from the perspective of suitability for the AI using a comparative content analysis. The main result of this manuscript is the proposal of a fully customized approach to GHG emission calculations in RFT for the AI. This approach was proposed, applied, and verified in the form of an interpretative case study. The use of this approach can be expected in support of logistic planning and decision making.

Harvesting ambient mechanical energy by multiple mode triboelectric nanogenerator with charge excitation for self-powered freight train monitoring

Railway freight transportation is an important way of land transportation. Due to the lack of on-board power supply of large number freight train carriages/containers, the power supply of electronic equipment for monitoring a train carriage is very difficult. Therefore, a self-powered real-time monitoring system is desperately necessary by in-site energy harvesting strategy. Herein, a multiple mode triboelectric nanogenerator (MM-TENG) assembled by multilayer floating sliding part and multilayer wave-shape contact-separation part is designed to collect the ambient mechanical energy on the freight train carriage joints to power the sensors for monitoring the train state. The multilayer floating sliding part effectively avoids the abrasion on the interface of tribolayers and easily harvests small trigger energy. The multilayer wave-shape contact-separation part is divided into several layer units, where only one-layer unit is used as a charge excitation TENG for the charge supplement to the whole TENG including multilayer floating sliding part and the rest of multilayer contact-separation part, which greatly improves the output performance of MM-TENG. The device parameters and test conditions are systematically investigated for optimizing output performance. The transferred charge of MM-TENG reaches 3.2 μC by the normal triggering of linear motor at 2.5 Hz and a 470 μF capacitor is charged to 5.2 V in 100 s. The lighting of 944 LEDs, the operation of temperate-humidity meter and the driving of a fire alarm after an energy management prove it as effective power supply for the sensors. This in-situ energy harvesting approach can be used in many fields for self-powered monitoring systems.

Quantifying Recent Trends in Class 1 Freight Railroad Train Length and Weight by Train Type

Railroads have a strong economic incentive to maximize the length and weight of freight trains. Since the mid-1990s, various technological innovations have facilitated operation of longer and heavier trains, and railroads have made infrastructure investments to accommodate them. Recent shifts in railway operating and management strategies have placed added emphasis on long trains but have also drawn public and agency scrutiny. The advantages and disadvantages of increased train size are difficult to analyze because public data on train length and weight over time are limited. Articulated intermodal railcars, artificially short local trains, and light empty unit trains skew industry averages across all train types and mask trends over time. To provide greater insight on the average and distribution of train length and weight for different train types over time, the research team conducted a detailed analysis of Class 1 railroad annual report financial data and Surface Transportation Board waybill sample data collected for the years 1996 through 2018. Dividing traffic statistics by train type allows for a specific focus on loaded unit train length and weight distributions that isolates many factors skewing overall averages. Over the past 23 years, the average length and weight of loaded non-hazmat unit trains have steadily increased. Train size distributions indicate that unit trains exceeding 140 railcars in length have become more frequent over the past 10 years, whereas hazmat unit trains are typically smaller in size. This information can aid researchers and industry practitioners in assessing the benefits and disadvantages of operating longer trains.

The Impact of the Internalization of External Costs in the Competitiveness of Short Sea Shipping

This paper applies a methodology for computing external costs in an intermodal transport network that includes short sea shipping to explore the impact of external costs in its competitiveness. The network, which includes roads, freight railways, maritime and inland waterway connections, considers the specific characteristics of different transport alternatives and vehicle types, providing a fair comparison of the various modes. A case study focused on freight transportation between Northern Portugal and 75 destinations (NUTS2 regions) in north-western Europe is presented. The potential of different intermodal routes that include short sea shipping is assessed, including not only internal costs and times but also external costs per mode and unit of cargo. The impact of the different cost approaches in each country of transit is shown along with the progress that has been made in the integration of external costs, using the most recent EU estimates on marginal costs coverage ratios per country for freight transport modes. The results support the modal shift from road to sea in this corridor, providing means for modal comparison and for the development of short sea shipping’s image as a sustainable mode of transportation.

Negative Sequence Current and Reactive Power Comprehensive Compensation for Freight Railway Considering the Impact of DFIGs

To solve the power quality problems caused by freight railways in weak grids with high penetration of wind generation, this paper proposes a comprehensive control method for negative sequence current (NSC) suppression and reactive power compensation. Firstly, a co-phase traction power supply system (CTPSS) is introduced, and its compensation principle is analyzed. Secondly, to bring a doubly fed induction generator (DFIG) into full play in suppressing voltage unbalance (VU) in the grid, a VU compensation model of stator is developed. Moreover, a comprehensive compensation method is presented to achieve the dynamic compensation of VU and reactive power. Finally, the effectiveness of the proposed approach is demonstrated using a simulation, which can fully solve the power quality issues and effectively reduce the capacity of the CTPSS.

Comprehensive Evaluation Model and Empirical Research on Railway Freight Rates in a Competitive Environment

This study aims to establish criteria to evaluate performance in railway freight pricing policy and to strengthen the marketing ability of the railway freight enterprise. The evaluation method used in our study is known as the improved grey relation analysis evaluation. Fifteen factors that influence freight pricing strategy are selected in this paper to establish a freight rate evaluation index system and comprehensive evaluation index values for monthly freight rates are calculated. The improved grey relation analysis not only considers the relation between each index and freight rate but also examines the relationship between each index. We find that the comprehensive evaluation state using the improved grey relation analysis evaluation method can better fit the 2015–2017 changes in monthly railroad freight revenue than the traditional grey relation analysis evaluation. Furthermore, an optimal pricing model for freight shipping by train is built and calculated using the bi-level programming model. Finally, the S Railway Bureau’s actual coal transportation in 2017 is taken as an experiment to support the validity of the improved grey relation analysis method. We find that when the monthly results of improved grey evaluation grades are compared with the grade evaluation of the gap between the historical shipping coal rates and the optimal freight shipping rates, the comparison of results matches well. The research work is helpful to policymakers who need to judge the performance of the market price.