Empty Cars Research Articles

Современные методы управления парком приватных вагонов

Purpose: To study modern approaches for management of privy railcar park. At the moment, the lack of cars on loading stations is observed while their common surplus. This can be overcome by agreed supply of empty cars at set time interval. For to satisfy clients’ needs in complex service it’s proposed to apply new informational products and services. The application of ERP-systems (Enterprise Resource Planning) will allow to rise the efficiency of interaction between operator companies and JCS RZD. Methods: Application of method of digital solutions while car flow management, design of digital systems of transportation process management. Results: In the investigation, the methodology is proposed of optimal distribution of car park by loading stations on railway network JSC RZD. Practical importance: Deficit and surplus elimination for car park in operator company management, reduction of exploitational burden on JSC RZD infrastructure. Effective usage of new informational products will allow to use effectively the privy rolling stock.

Optimization of Empty Wagon Flows in the Formation of the Technical Work Plan for the Railway Network

At present, the Russian railway network is experiencing a shortage of throughput capacity. At the same time, for a number of reasons, the direction of empty cars for loading is not always performed optimally, which leads to the presence of empty runs of cars of the same type and additional loading of limiting railway infrastructure facilities. In order to improve the rationality of empty wagon direction, it is proposed to calculate the optimal empty wagon directions at the stage of calculation of technical standards of operational work with their subsequent use in operational management and creation of economic incentives for their implementation.

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

CD72 Nanobody-Based CAR-T Cells Have Potent Anti-Tumor Efficacy in B Cell Malignancies

Background: Approximately 50% of pediatric B-ALL patients treated with clinically approved CD19-targeting CAR-T cells do not remain in remission one year after therapy. CD22-targeting CAR-T cells appear to be curative in only a small fraction of CD19-refractory patients and this therapeutic strategy is primarily used as a bridge to stem cell transplant. Additional immunotherapeutic targets thus remain urgently needed. Our laboratory recently used cell surface proteomics to identify CD72 as a B-cell specific marker especially upregulated on poor prognosis, KMT2A/MLL-rearranged B-ALL (Nix et al., Cancer Discovery (2021)). In this published work, we used a best-in-class nanobody library displayed on yeast to develop binders to CD72. We demonstrated for the first time that fully synthetic nanobodies can generate CAR-T cells that are highly potent in vitro and in vivo. While we previously focused on these “nanoCARs” in KMT2A/MLLr B-ALL, in this follow-up study we aimed to 1) further expand our nanoCAR indications to other CD72-expressing B-cell malignancies; 2) biophysically characterize our synthetic nanobodies; 3) evaluate the potential for further humanization of the nanobody binder amino acid sequence while retaining anti-tumor efficacy; and 4) characterize the potency and T-cell immunophenotypes in the context of our lead nanobody binder (“NbD4”) placed on different CAR backbones.Methods: Flow cytometry of primary patient samples for CD72 was performed in a CLIA-certified laboratory. NbD4 nanobody was recombinantly expressed in E. coli and biolayer interferometry was used to determine the binding affinity to recombinantly-expressed CD72 extracellular domain. CAR-T cells were generated from peripheral blood donor CD4+ and CD8+ cells (1:1) ratio via lentiviral transduction. In vitro cytotoxicity assays were performed at a range of effector:tumor ratios. In vivo studies were performed in human cell line orthotopic xenografts in NSG mice. 1e6 luciferase-labeled Jeko cells were implanted at Day 0 followed by administration of 4e6 CAR-T cells at Day 6. Tumor burden was assessed by bioluminescence.Results: Flow cytometry on primary non-Hodgkin B-cell lymphoma obtained from fine needle aspiration biopsy (n = 5) confirmed CD72 surface expression (not shown), consistent with RNA-seq across larger cohorts. Biolayer interferometry demonstrated that NbD4 bound with surprisingly low affinity to recombinant CD72 (K D ~800 nM) (Fig. 1A), with both slow on rate (k on 8.38e4 M -1s -1) and rapid off rate (k off 6.82e-2 s -1). This affinity stands in contrast to that reported for FMC63 single chain variable fragment (scFv) used in clinically approved CD19-targeting CAR-T cells (K D 0.3-5 nM), despite similar in vitro and in vivo efficacy of both products. Our NbD4 framework region shows ~82% homology to a human IgG variable heavy domain, significantly higher than FMC63 (~59% homology). We made additional substitutions in the framework domain to increase human homology up to 89%. In vitro cytotoxicity assays with SEM B-ALL cells showed several humanized variants with similar efficacy to NbD4 (Fig. 1B). We further evaluated the impact of placing NbD4 on different CAR backbones, including combinations of CD28 or 4-1BB costimulatory domains and CD8 or IgG4-based transmembrane and hinge regions (Fig. 1C). In vivo, CD72 nanoCARs with Backbone 3 showed significantly increased potency (Fig. 1D). Indeed, tumors treated with Backbone 3 CAR-Ts showed complete tumor clearance and did not develop new tumors even after re-challenge with 1e6 Jeko cells at Day 52 (Fig. 1D). Preliminary characterization of effector and memory CAR-T cell phenotypes before exposure to tumor suggested that Backbone 3 had an increased number of naïve T cells compared to empty CAR and CD19 CAR-T cells (data not shown).Conclusions: Our results demonstrate that our fully synthetic CD72 nanoCARs can effectively eliminate CD72-expressing B-cell malignancy models despite low nanobody binding affinity. Humanized NbD4 variants may serve as clinical candidates with even further reduction in possible immunogenicity of the llama amino acid framework. Alterations to the CAR backbone have a major impact on anti-tumor efficacy and phenotypes of our synthetic nanobodies. CD72-targeting therapies may be effective therapeutics not only KMT2A/MLLr B-ALL but also across a broader spectrum of refractory B-cell malignancies. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A classification method for urban functional regions based on the transfer rate of empty cars

Predicting the nature of each urban functional region based on the transfer rate of empty cars plays a crucial role in constructing smart cities and urban planning. The transfer rate of empty cars describes the probability of a taxi driving from one region to another without any passengers. It can reflect the main driving directions of taxies and the main flow directions of people among different urban functional regions. Although current researches have focused on the functional regions divided by remote sensing satellite images, there is almost no discussion on determining the nature of the region through taxi behaviour. The authors consider using taxi behaviour to classify urban functional regions. Besides, the attentional spatio-temporal model (Attentional Gated Recurrent Unit, AGRU) is introduced in the work. The AGRU consists of three modules, which are the spatial feature extraction module, the temporal feature extraction module, and the attentional pooling mechanism. The model has been evaluated on the data set provided by Didi Chuxing and it has been compared with some typical models. The experimental results show that the AGRU can reflect spatio-temporal information, and its attentional pooling mechanism can distinguish whether a region is the place of departure or the destination.

Empty Car Distribution Considering Timeliness Requirement at Chinese Railways

AbstractDue to variations in freight traffic arising in daily operations, railways need to develop a distribution plan to determine the actual movements of empty cars every day. This paper investig...

Simulation model of oil products transshipment in a seaport

The paper considers the problem of finding an optimal strategy for ordering railway tank cars for the export of oil products from the seaport terminal. Since the arrival of the ordered wagons is a random process that substantially impacts the costs of the cargo owner, it was decided to use the simulation modeling method to solve the problem. The paper provides an overview of methods and specific examples of simulation modeling for solving related problems in transport logistics. Particular attention is paid to the experience of using spreadsheets in the practice of simulation modeling. It is noted that a spreadsheet as a modeling tool has certain advantages over special packages for simulation modeling. The paper substantiates the decision to use the VBA language in the MS Excel environment to develop a model for the transshipment of oil products at the terminal in the seaport. The following details describe the stage of conceptual modeling, the stage of data preparation using distributions of random variables, and conducting experiments with the model. Five possible scenarios were investigated, which differ in the boundary conditions of the processes of the arrival of empty cars at the terminal. Based on the results of the study of these scenarios using statistical modeling methods, the requirements were developed that the cargo owner must impose on the railway in order to minimize the costs arising both from the delay of the vessel in the port and the idle time of wagons on the terminal territory. Key words: Oil Products Transshipment, Marine Oil Terminal, Simulation, Spreadsheet.

A Dynamic Tree Algorithm for Peer-to-Peer Ridesharing Matching

On-demand peer-to-peer ridesharing services provide flexible mobility options and are expected to alleviate congestion by sharing empty car seats. An efficient matching algorithm is essential to the success of a ridesharing system. The matching problem is related to the well-known dial-a-ride problem, which also tries to find the optimal pickup and delivery sequence for a given set of passengers. In this paper, we propose an efficient dynamic tree algorithm to solve the on-demand peer-to-peer ridesharing matching problem. The dynamic tree algorithm benefits from given ridesharing driver schedules and provides satisfactory runtime performances. In addition, an efficient pre-processing procedure to select candidate passenger requests is proposed, which further improves the algorithm performance. Numerical experiments conducted in a small network show that the dynamic tree algorithm reaches the same objective function values of the exact algorithm, but with shorter runtimes. Furthermore, the proposed method is applied to a larger size problem. Results show that the spatial distribution of ridesharing participants influences the algorithm performance. Sensitivity analysis confirms that the most critical ridesharing matching constraints are the excess travel times. The network analysis suggests that small vehicle capacities do not guarantee overall vehicle-kilometer travel savings.

Survey of air exchange rates and evaluation of airborne infection risk of COVID-19 on commuter trains.

To identify potential countermeasures for coronavirus disease (COVID-19), we determined the air exchange rates in stationary and moving train cars under various conditions in July, August, and December 2020 in Japan. When the doors were closed, the air exchange rates in both stationary and moving trains increased with increasing area of window-opening (0.23-0.78/h at 0m2, windows closed to 2.1-10/h at 2.86m2, fully open). The air exchange rates were one order of magnitude higher when doors were open than when closed. With doors closed, the air exchange rates were higher when the centralized air conditioning (AC) and crossflow fan systems (fan) were on than when off. The air exchange rates in moving trains increased as train speed increased, from 10/h at 20km/h to 42/h at 57km/h. Air exchange rates did not differ significantly between empty cars and those filled with 230 mannequins representing commuters. The air exchange rates were lower during aboveground operation than during underground. Assuming that 30-300 passengers travel in a train car for 7-60min and that the community infection rate is 0.0050-0.30%, we estimated that commuters' infection risk on trains was reduced by 91-94% when all 12 windows were opened (to a height of 10cm) and the AC/fan was on compared with that when windows were closed and the AC/fan was off.

Effect of carbody flexibility on the dynamic performance of an empty freight wagon

The structural flexibility of passenger car bodies is paid most attention in research due to the effect it has on the passenger ride comfort. But as we are moving towards high speed and lightweight freight Railway stock, the issue of structural flexibility becomes essential in the case of freight wagons also. This paper investigates the effect of including the structural flexibility of the carbody of Indian Railway open freight car BOXNHL in the dynamic analysis. A mid surface meshed model of the subject carbody is developed using Hyperworks. Then, modal analysis is done using MSC FEA to identify the dominant flexible body modes. A simulation study has been conducted using NUCARS (New and Untried Car Analytic Regime Simulation) for an empty freight car on straight track and curve. Four types of carbodies have been considered for comparison- rigid carbody, flexible carbody having modal damping factor 0.04, 0.03, and 0.02. Vertical and lateral accelerations are chosen as the representative dynamic response parameters. The novelty of the present work lies in analyzing the effect of modal damping factors on the different response parameters (vertical and lateral accelerations) of empty BOXNHL freight wagon at different speeds. The field test results have been compared with the simulation results for identifying the modal damping factor with a minimum standard deviation.

On the permissible speeds of empty freight cars mounted on 18-100 model bogies

Problem of ensuring motion safety of empty freight cars is most acute in relation to cars on bogies of model 18-100, which is mainly due to operational wear of wheelsets, side frames and bolsters, as well as spring suspension elements. A potential threat to traffic safety arises when a train, composed of mostly empty and lightly loaded cars, moves along track sections that have deviations in the geometry of rail track of III and higher degrees or combinations and sequences of deviations of II degree. The article presents the main results of complex studies: mathematical modeling of the dynamic interaction of the track and empty freight cars of various types of bogie wear based on the Universal Mechanism software and field tests of cars on measuring sections of tangent, easement and circular curves with a radius of 350, 650, 800, 1000 and 2050 m on the section Belorechenskaya — Maykop of the North Caucasian railway. Dynamic qualities and motion stability of empty freight cars of various types are investigated depending on the parameters of the technical condition of the running gears and the deviations of the geometry of the rail track of II and III degrees of various types and combinations when moving in tangent and curved track sections. Authors provide tables and graphs of the dependences of indicators of dynamic qualities and motion stability of universal empty freight cars of various types on the motion speed in tangent sections of the track and circular curves of various radii and easement curves containing artificial deviations of the geometry of the rail track, most negatively affecting traffic safety. Recommendations are given for correcting the regulatory documents of the Russian Railways, which regulate the permissible speed of motion of empty freight cars, depending on the technical condition of the running gear.

Preclinical Evidence of the Efficacy of Lewis Y Car T Cells in Patient-Derived Models of Prostate Cancer

Chimeric antigen receptor T (CAR T) cell therapy is an adoptive immunotherapy that has led to new treatments for lymphoma, leukemia, and other blood cancers; however, its efficacy for prostate cancer remains unproven. Here we report pre-clinical evidence of the efficacy of CAR T cell therapy against the Lewis Y antigen (LeY) using patient-derived models of prostate cancer. To assess the expression of LeY on prostate tumours, we performed immunohistochemistry on a cohort of 41 patient-derived xenografts (PDXs). Cytoplasmic and membrane expression were separately assessed and quantified, for each patient. Overall, 61% (25/41) of PDXs were positive for membrane LeY expression, of which 18 PDXs had greater than 50% membrane-positive cells, and considered most suitable to detection and stable binding by anti-LeY CAR T’s. To determine the in vitro sensitivity to CAR T cytotoxicity, we selected 4 PDXs with high and 2 PDXs with low LeY expression using 3 androgen receptor (AR)-positive adenocarcinomas and 3 AR-negative tumors expressing neuroendocrine markers. Next we established organoids for in vitro co-culture assays where organoids were co-incubated with an equal number of anti-LeY+ CAR T cells or Empty vector control CAR T cells (Ev CAR T). Using time-lapse microscopy we reported destruction of organoids by LeY+ CAR T cells as indicated by their morphological collapse and uptake of propidium iodide from the culture medium; control Ev CAR T cells produced no cytotoxicity. Over the 48h assay, the level of target cell death of the LeY+ organoids was correlated to the intensity LeY surface expression. Target cell death mediated by the CAR T cells required perforin and granzyme B, as potent and highly specific small molecule inhibitors of perforin (SN34960) and granzyme B (C20) applied alone or in combination greatly decreased PI uptake, indicating organoid survival. Neither inhibitor adversely affected CAR T cell viability as measured by PI and Annexin V staining. This demonstrated canonical activation of granule exocytosis pathway by the CAR T cells, leading to organoid cell death. To assess CAR T cell efficacy in vivo, we selected one PDX with high LeY expression. Monotherapy with CAR T cells failed to decrease tumour volume compared to vehicle control. However, CAR T cells given after a single dose of the chemotherapeutic agent carboplatin greatly and durably reduced tumour burden, with residual tumour mass being less than 1% of their original size (0.56 ± 0.23% of tumour volume at the start of treatment). Overall, these data provide preclinical evidence that: i) high membrane expression of LeY correlates with in vitro and in vivo CAR T cell-induced tumour cell death via the canonical perforin/granzyme B mechanism; and, ii) membrane LeY can be used as a biomarker for patient selection.

Analysis of the conditions for the exhaustion of the stability margin in the rail track of freight cars with three-piece bogies

The research on improvement of methodical approaches to definition of the probable reasons of infringement of conditions of stability of freight cars from derailment is carried out. Using a basic computer model of the dy-namics of a freight car, the influence of the characteristics of the technical condition of their running gear and track on the indicators of empty cars stability from derailment was studied through the computational experi-ment. The article presents the main statements of the research methodology, which provides the analysis of probable causes of derailment of freight cars by conducting a series of numerical experiments with logging the progress of calculations and saving the results. Factor analysis was used to interpret the calculated data with an assessment of each of the factors influence or their combination on the probability of derailment. The developed procedure of the simulation experiment provides a step-by-step study of the freight cars derail-ment conditions, including factors structuring and ranking, development of experimental plan, calculating coef-ficients of wheel pairs resistance to derailment from rails, provided that the wheel flange rolls onto the rail head, and determining the degree of influence of relevant factors on the dynamic stability of cars from derailment. A comparative analysis of the stability of cars in rail tracks was performed using the introduced concept of the combined coefficient of stability of wheel pairs against derailment. Determining the probable causes of car derailment is based on scanning the parameter field. The results of the parametric study revealed the degree of influence on the freight cars stability of running gear technical condition characteristics. In particular, it is determined that the most dangerous in terms of stability loss of empty cars in the track is the exceeding of the wedges of the vibration dampers.

Investigation of the Influence of Forming Routes from Empty Cars on the Processing Capacity of Codriving Slides

The article discusses issues related to the formation of empty cars according to the type of rolling stock and by owners, their possible assembly points, an analysis of the formation plan from empty cars is carried out in order to select a station for the concentration of empty cars according to the type of rolling stock and the routes of their access to them. The analysis of groups of wagons that can be organized into exit routes is carried out. The criteria of the set optimization task for the moving of empty cars and improvement of the quality indicators of operational work for JSC Russian Railways have been substantiated. The dependence of the destination capacity on the number of destinations formed by trains at the Khabarovsk II station has been determined.The scientific challenge to be solved by the project: the irrational use of the car fleet and the estimated capacity of the gravity humps.

Research of the Vertical Dynamics of the Supporting Structures of Freight Cars Made of Round Pipes

Purpose. This study is aimed at determining the vertical dynamics of supporting structures of freight cars made of round pipes. Methodology. Mathematical modeling of the dynamic loading of the supporting structures of the main types of freight cars made of round pipes (gondola car, covered car, flat car, hopper car) was carried out. The studies were carried out in a plane coordinate system – the XZ plane. At the same time, it was taken into account that the car is moving in an elastic-viscous track so that the reactions of the track are proportional to both its deformation and the rate of this deformation. The studies were carried out for the case of empty cars. The joint inequality is described by a periodic function. The calculation was performed at a speed of 80 km/h. Differential equations of motion were solved in the MathCad software package using the Runge-Kutta method. Findings. Based on the mathematical modeling of the dynamic loading of the supporting structures of cars made of round pipes, the main indicators of their dynamics were obtained: accelerations acting on the supporting structures in the mass center, forces acting in the spring suspension of bogies, dynamics coefficients. For gondola car, covered car, and hopper car, the acceleration at the mass center of the supporting structure is within 0.4 g, and for a flat car – 0.5 g. It was found that the obtained indicators of the dynamics of cars made of round pipes are within the permissible limits. The accelerations acting on the supporting structures of cars made of round pipes are almost the same as those obtained for prototype cars. At the same time, the motion of cars is assessed as "excellent" for gondola car, covered car, and hopper car and "good" for flat car. Originality. Mathematical modeling of the dynamic loading of the supporting structures of cars from round pipes was carried out and the main indicators of their dynamics were obtained. Practical value. The research carried out will contribute to the creation of recommendations for the design of supporting structures of freight cars of round pipes, and can also be useful developments in the creation of innovative car designs.

Проблемные аспекты в реализации информационной технологии «Автоагент» на железнодорожном транспорте (на примере Восточно-Сибирской железной дороги)

The article presents the technology of the railway divisions in handling the automatic registration of shipping documents for transportation of empty gondola cars in domestic traffic (“Autoagent”). Regulatory and technical documents defining the procedure for the implementation of the technology are studied in detail, and some setbacks in the registration of transportation documents based on paper medium are identified. The “Autoagent” system failures after updating the AS ETRAN program, which is in constant operation on the East Siberian Railway, are determined and analysed. Conclusion on the implementation and improvement of the experimental technologies and various programs that are in constant use are made.

EVALUATION OF DYNAMIC QUALITIES OF MOVEMENT OF RE-EQUIPPED HOPPER CARS OF PILS OF LONG-TERM OPERATION

As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer simulation of the dynamics of empty hopper wagons converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container, the repeated presence of maximum vertical deviations and horizontal deviations of the track. A significant disadvantage of the railway transport of Ukraine is the limitation of the speed of trains with individual freight cars in an empty state, which are equipped with carts model 18-100. Among the reasons for the descent of the wheels of cars from the rails are: malfunctions of the running gear of the cars (fracture of the side frames and spring beams of the carts, malfunctions of the roller bearings of the axle box), wear of friction damper elements, unacceptable deviations and upgrades. As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer modeling of the dynamics of empty hopper wagons, converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container and studies of the dependence of the wheel stability on the east.

ОЦІНКА ГАЛЬМІВНОЇ ЕФЕКТИВНОСТІ ВАГОНА ЦИСТЕРНИ МОДЕЛІ 15-7140 НА ДОТРИМАННЯ ВИМОГ ГОСТ 34434-2018

Results for study of the braking efficiency of tank car model 15-7140 for compliance with requirements GOST 34434-2018 are given. Research was performed using method of “throwing”, and data processing was performed using special drawn up ECM program taking into account actual tank parameters. Braking coefficients of a single car were recalculated to maximum car loading taking into account axle loading, and to minimal pressure in the braking cylinder of loaded and empty cars. It was determined that the braking distance of the train of the site of loaded tank cars model 15-7140 corresponds to the braking efficiency requirements of GOST 34434-2018 for running speeds of 90 km/h, braking distances of the empty car are within acceptable values for speeds to 120 km/h inclusive.

Optimization of Logistics Services in Vietnam Through LOGIVAN Application

Logistics is a type of service that plays an important role in promoting the country's economic growth. In addition, it is also of great significance to the transport sector in Vietnam in dealing with the challenges of traffic congestion in large cities. In Vietnam today, logistics services are growing. However, there is one major limitation that still exists, that is freight costs are still high. This does not meet the best requirements of customers. There are many reasons for this problem, one of the reasons is that trucks only carry one-way cargo, but there are no goods to ship backwards. The paper studies the application of LOGIVAN smart transport model in developing Logistics services in Vietnam today. Research results show that LOGIVAN transport model is the optimal model in solving the problem of empty cars in the transport of goods when they go back to the place of departure. This helps minimize Logistics costs for businesses, increases income for drivers and leads towards sustainable transport development. LOGIVAN develops two platform solutions for goods owners and vehicle owners. Accordingly, the author of the article confirms the quality of this model in developing Logistics services in Vietnam and guide the operation for users via applications on personal mobile devices at the same time. Keywords: Logistics; LOGIVAN; Vietnam. DOI: 10.7176/JESD/10-14-01 Publication date: July 31 st 2020

Modeling and optimization of plans for railway freight transport performed by a transport operator

This paper offers one approach for solving a problem that arises for railway transport operators. The task is to manage the fleet of freight railcars optimally in terms of profit maximization. The source data for the transport operator is a list of requests received from customers, as well as the location of railcars at the beginning of the planning period. The request formed by each customer consists of departure station, destination station, name and volume of cargo that the customer would like to transport. The request also contains the rate that the customer has to pay to the transport operator for each loaded wagon transported. Planning is carried out for a month in advance and consists, on the one hand, in selecting the most profitable requests for execution, on the other hand - in building a sequence of cargo and empty runs that will fulfill the selected requests with the greatest efficiency. Direct transportation of loaded and empty railway cars is carried out by Russian Railways with pre-known tariffs and time standards for each of the routes. At the same time, tariffs for driving loaded wagons are additional costs for the customer of the route specified in the request (customers pay both the transport operator for the use of wagons and Russian Railways); transportation of empty wagons is paid by transport operators. To solve this problem, one of the possible ways to reduce it to a large-dimensional linear programming problem is proposed. An algorithm is proposed, the result of which is a problem written in the format of a linear programming problem. To demonstrate the approach clearly, a simplified problem statement is considered that takes into account only the main factors of the modeled process. The paper also shows an example of a numerical solution of the problem based on simple model data.