scholarly journals Principles of the Feedback Action in Local Elements of Rail Yard Interaction

2018 ◽  
Vol 7 (4.3) ◽  
pp. 196
Author(s):  
Petro Yanovsky ◽  
Victoriia Yanovska ◽  
Sergiy Lytvynenko ◽  
Halyna Nesterenko ◽  
Larysa Lytvynenko

Achievement of high-quality servicing level of cargo owners should be carried out under unconditionally effective use of rolling stock of railways and technical means. The real transport process should be implemented based on logistic cargo supply chains by types of connections for each shipment. The practice of railway operation shows that there is a significant shortage of train locomotives as a result of which the departure of ready trains at rail yard is often not carried out. In such cases, a feedback effect in local elements of interaction of these stations occurs. Due to delay in departure of trains, sending of already formed trains from rail yards is delayed; furthermore, because of the overflow of rail yard tracks, the sorting process on marshalling humps can be slowed down and delay of prepared trains for dismantling at arrival yard may occur. As a result of feedback action, downtimes of rail cars are increasing and movement of inventories is slowing down. In order to mitigate feedbacks effects in local elements of interaction, the principles of their operation, consideration of which will enable acceleration in passage of the rail car and cargo traffic through the railway network in practical activity, were formulated.  

2021 ◽  
Vol 13 (12) ◽  
pp. 6948
Author(s):  
Svetla Stoilova ◽  
Nolberto Munier

This study is useful for railway operators as it enables them to verify their decisions against the results of the application of the techniques of strategic planning and multi-criteria analysis. It gives railway stakeholders concise, objective and unbiased information so that they can then make decisions and also allows them to determine the strengths and sensitivity, of the best solution found. This paper presents a methodology for the assessment of the policies of railway operators using Strengths–Weakness–Opportunities–Threats (SWOT) criteria and the Sequential Interactive Modelling for Urban Systems (SIMUS) method. The methodology of the research consists of two stages. In the first stage, the alternatives of the policies for the railway operator are formulated; the criteria in the SWOT group are defined; and the values of the criteria are determined for each of the alternatives. In the second stage, the SIMUS method is applied to rank the alternatives and assess the criteria in the SWOT groups. The criteria are interpreted as objectives and linear optimizations are performed. A comparison between the desired values for each objective of the SWOT criteria and the optimum values of the objective functions obtained by SIMUS was made. The methodology was applied to the Bulgarian railway network. Three policies for railway operation were studied. The total number of 17 railway policies criteria in the SWOT group were defined and assessed—three strengths criteria, seven weaknesses criteria, three opportunities criteria and four threats criteria. The results indicated that the best strategy is A3 (some reconstruction of the railway infrastructure and new rolling stock on some lines), with the highest score of 3.76, followed by A2 (new rolling stock on some lines), with a score of 2.71. The status-quo strategy (A1) has a very low score of 0.43, that the current situation or status-quo cannot be supported. The weights of both strengths and opportunities are both of the same importance with a weight of 0.180. It was found out that the clusters Weakness and Threats are dominant with weights of 0.4 and 0.24 respectively. The results show that the weights are all practically the same, about 0.06, and therefore, no discrimination by importance is possible. The methodology makes it possible to consider the alternatives simultaneously, and in this way, the results will reflect the effect of one criterion on all others, and permit us to quantify the differences between expected and real results.


2018 ◽  
Vol 77 (4) ◽  
pp. 211-217 ◽  
Author(s):  
P. N. Pulatov

Current geopolitical and economic conditions for the functioning of railway transport in most post-Soviet states are such that it is extremely difficult to provide required quality of transport services and break-even operations at high expenses for maintaining the railway infrastructure and rolling stock. Dynamics of transportation of the Tajik Railway (TSR) is shown, which displays that most of its sections are classified as low-intensity ones. The paper proposes methodical principles, setting and qualitative analysis of the task of rationalization of operational work and organization of car flows for international transportation, taking into account the specifics of the Tajik Railway. There is a problem of complex maintenance of the efficiency of operational work in modern conditions based on the synthesis of the tasks of self-management (rational internal operational technology of the Tajik Railway) and coordination tasks (technological interaction with railway administrations of other states). Author substantiated the necessity of solving this problem. Proposed classification of technological restrictions and controlled variables in the performance of transport takes into account methods for changing external conditions for the functioning of the railway landfill and methods for increasing internal efficiency of its operation. The search for the solution of the problem involves direct search of variants along its ordered set with clipping of groups of variants that do not correspond to constraints, with the subsequent finding of compromise control over a set of effective alternatives.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Qin Zhang ◽  
Xiaoning Zhu ◽  
Li Wang ◽  
Shuai Wang

The optimization problems of train timetabling and platforming are two crucial problems in high-speed railway operation; these problems are typically considered sequentially and independently. With the construction of high-speed railways, an increasing number of interactions between trains on multiple lines have led to resource assignment difficulties at hub stations. To coordinate station resources for multiline train timetables, this study fully considered the resources of track segments, station throat areas, and platforms to design a three-part space-time (TPST) framework from a mesoscopic perspective to generate a train timetable and station track assignment simultaneously. A 0-1 integer programming model is proposed, whose objective is to minimize the total weighted train running costs. The construction of a set of incompatible vertexes and links facilitates the expression of difficult constraints. Finally, example results verify the validity and practicability of our proposed method, which can generate conflict-free train timetables with a station track allocation plan for multiple railway lines at the same time.


Author(s):  
Kleopatra Alamantariotou

Recent statistics show that the World Wide Web has now grown to over 100 million sites: a phenomenal expansion in only 15 years (Mulligan 2007). It has been estimated that there are 100,000 sites offering health related information (Wilson 2002). As the amount of health information increases, the public find it increasingly difficult to decide what to accept and what to reject (Burgess 2007). Searching for information on the internet is both deceptively easy and the same time frustratingly difficult (Kiley 2002). The challenge for consumers is to find high quality, relevant information as quickly as possible. There has been ongoing debate about the quality of information aimed at patients and the general public and opinions differ on how it can be improved (Stepperd 1999). The purpose of this chapter is to provide a brief overview of the different perspectives on information quality and to review the main criteria for assessing the quality of health information on the internet. Pointers are provided to enable both clinicians and patients find high quality information sources. An understanding of these issues should help health professionals and patients to make effective use of the internet.


2018 ◽  
Vol 180 ◽  
pp. 06005
Author(s):  
Andrzej Massel

The process of electrification of the Polish railways took place from 1936 till early 1990s. Despite the political constraints of the post-war times, the decisions on electrification of particular sections of the railway network were usually based on economic factors. In 1970s and 1980s so called electrification thresholds were used to justify the need for electrification of railway line in question. They took into the number of tracks (single-track lines, double-track lines), terrain conditions (flat terrain, upland terrain) and the traffic structure (the share of passenger traffic) into account. In the framework of National Railway Program till 2023 (KPK) the realization of electrification projects have been undertaken again. The present paper deals with importance of the operational criteria in the decision-making concerning justification of electrification of railway lines. These criteria include the shortening of the journey times on particular sections, shortening of stops on the stations with the change of the type of traction, the savings of train operating companies resulting from the traction unification (change of demand for rolling stock and for workshops for its servicing), improvement of reliability and punctuality of services.


2018 ◽  
Vol 180 ◽  
pp. 05003
Author(s):  
Marek Pawlik

Potential fire on board of the passenger train creates risk for passengers health and passengers life. Using non-flammable materials for producing Electric Multiple Units (EMUs) is not considered to be sufficient as passengers are carrying different types of materials as their luggage and belongings. In case of fire on board of the train, the EMU should stop in a place which is appropriate for passengers evacuation and fire fighting. Not all places along railway lines are considered to be appropriate for such purpose. Especially stopping in tunnels is considered inappropriate. Meanwhile the amount of tunnels on the Polish railway network is growing significantly. This requires application of the Technical Specification for Interoperability regarding Safety in Railway Tunnels (TSI SRT) and set of fire standards EN 45545. Using those requirements is associated with putting tunnels and rolling stock into service under railway interoperability directive 2008/57/WE. Additional analyse is however necessary from operational safety point of view due to growing amount of tunnels and growing diversity of rolling stock. Paper proposes conducting risk analyse in accordance with common safety method for risk evaluation and assessment based on a dedicated European Standard EN 50533 which defines requirements regarding running capability in case of fire on board of the rolling stock. Paper analyses applicability of that approach for group of tunnels and rolling stock fleet comprising different types of rolling stock including Electric Multiple Units.


2018 ◽  
Vol 19 (6) ◽  
pp. 176-179
Author(s):  
Jarosław Moczarski

An important factor improving the safety of the railway transport process is the automatic recognition of the rolling stock and the transported loads. Using modern data acquisition and analysis techniques allows to identify moving objects by assessing their shape and size. For the creation of digital models of the studied objects and their subsequent identification there was developed a computer application working in Matlab programming environment. The application use the functions of designing, implementing, visualizing and simulating neural networks. The configuration of the test stand allows for carrying out experiments using analog and digital sensors.


2020 ◽  
Vol 54 (2) ◽  
pp. 7-19
Author(s):  
Maciej Szkoda ◽  
Magdalena Satora ◽  
Zbigniew Konieczek

Based on the example of 6Dg type diesel locomotives, the paper presents a new maintenance strategy concerning periodical checks at the P1 maintenance level. Currently, such locomotives are sent off to service points every 102 hours of operation or every 14 days for a P1 level check. Studies demonstrate that the average distance to be covered by a locomotive to arrive at a service point is in excess of 60.0 km, and the quantity of fuel consumed is more than 88 litres. It is costly and time consuming to have locomotives out of service and considerable resources of the railway carrier are engaged which could be made use of in the transport process. The aim of the newly developed strategy of P1 checks is to eliminate the need for locomotives to exit their routes to reach rolling stock maintenance points. The control/diagnostic and maintenance activities specified in the Maintenance System Documentation will be performed by so-called mobile maintenance points. The development of the new strategy required: identification of the current condition of the maintenance system, development of the concept of a new strategy of P1 maintenance checks, conduct of studies and operational analyses for SM42 series locomotives, performance of a durability, reliability analysis, assessment of safety together with an analysis of the risks involved in the proposed changes. In order to review and assess the efficiency of the new strategy, an observed operation of selected locomotives was conducted together with a railway carrier. During the study, the maintenance activities and processes were monitored and the costs of P1 checks were recorded. The analysis of efficiency of the new strategy of performing P1 checks without the need for a locomotive to exit its route to reach a rolling stock maintenance point demonstrated that depending on the distance covered by the locomotive to reach a maintenance point, the unit costs of a P1 level check are lower by up to 67.1% compared with the currently applied method.


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