Safe Rail Transport via Nondestructive Testing Inspection of Rails and Communications-Based Train Control Systems

Author(s):  
Vassilios Kappatos ◽  
Tat-Hean Gan ◽  
Dimitris Stamatelos
Author(s):  
Klaus Jobmann ◽  
Simon F. Ruesche ◽  
Jan Steuer

The European Rail Transport Management System (ERTMS) was introduced by the European Union (EU) to harmonize the nearly 18 different national train control systems which are currently in use, to accelerate the interoperability of the passenger- and freight-transport and, finally, to increase the utilization of tracks by dynamic train control. The essential components of ERTMS are the train-specific, cellular, professional mobile radio system GSM-R (GSM-Railway) and the so-called European Train Control System (ETCS) which provides, by its second expansion stage (ETCS Level 2), the control- and signalling-information between the train and the related control location via GSM-R in a connection-oriented and wireless way. This wireless and connection-oriented approach will be the bottleneck of the system, which considerably limits the possible number of voice- and data-connections in each cell at the same time and will cause a deadlock of the system, if the number of users will rapidly increase (e.g. accidents, freight depots, lines with a high and dynamic volume of traffic). Within this paper the first part of a packet-switched approach is presented to counteract this expected deadlock by taking into account that the GSM-R infrastructure, which is often already installed by the national railroad operators, also should be used to save the high capital investment of those companies.


2020 ◽  
Vol 131 ◽  
pp. 99-118
Author(s):  
Aleksandra Modrzejewska

Rail transport adapts to the requirements of the modern agglomerations and provides solutions that ensure greater speed and capacity, while being environmentally friendly. Alternative means of rail transport as well as train control systems are proposed. The basis of innovative, effective, attractive and, above all, safe railway is a traffic automation, which can be implemented to a varying range and degree. Automation of systems of the train control and railway traffic management is an area that is constantly being scientifically researched and developed. The most technologically advanced control systems, in which the human factor is eliminated, are CBTC systems. This article presents the characteristics and components of one of the CBTC class family solutions used in the world, i.e. Bombardier’s product - CITYFLO 650. On the example of the CITYFLO 650 solution, the analysis of the fully automatic train operation was performed. Each of the stages of the fully automatic train operation was included in this paper. The conducted analysis confirms the legitimacy of using the CBTC technology on very demanding city lines. Bidirectional train-to-wayside data communications and determination of train location to a high degree of precision make it that CBTC systems fulfill the criteria set by large, fast-growing cities and a growing population. Poland, as a country currently looking for solutions that would reduce the transport problems of large cities, is considering such innovative proposals for rail traffic.


2011 ◽  
Vol 2-3 ◽  
pp. 785-790
Author(s):  
Jong Hyen Baek ◽  
Yong Kyu Kim ◽  
Jae Ho Lee ◽  
Hyen Jung Jo

For the purpose of improving the future domestic train control systems and securing interoperability, according to the global development trends of train control systems, it is presented that the test results of interoperability between wayside train control systems installed in existed line, and the onboard train control system. Due to the safety-critical characteristics of train systems, the site test in the section where the wayside equipment is installed may lead to a danger against safety. Therefore, by way of constructing a simulation environment of train control systems, the T/R data systems of the equipment for interoperability are confirmed and the interoperability test are obtained by applying these systems to onboard equipment.


Author(s):  
David F. Thurston

The main objective in optimizing train control is to eliminate the waist associated with classical design where train separation is determined through the use of “worst case” assumptions that are invariant to the system. In fact, the worst case approach has been in place since the beginning of train control systems. Worst case takes the most conservative approach to the determination of train stopping distance, which is the basis for design of virtually all train control. This leads to stopping distances that could be far more that actually required under the circumstances at the time the train is attempting to brake. Modern train control systems are designed to separate trains in order to provide safety of operation while increasing throughput. Calculations for the minimum distance that separates trains have traditionally been based on the sum of a series of worst case scenarios. The implication was that no train could ever exceed this distance in stopping. This distance is called Safe Braking Distance (SBD). SBD has always been calculated by static parameters that were assumed to be invariant. This is, however, not the case. Parameters such as adhesion, acceleration, weight, and reaction vary over time, location or velocity. Since the worst case is always used in the calculation, inefficiencies result in this methodology which causes degradation in capacity and throughput. This is also true when mixed traffic with different stopping characteristics are present at the same time. The classic theory in train control utilizes a SBD model to describe the characteristics of a stopping train. Since knowledge of these conditions is not known, poor conditions are assumed. A new concept in train control utilizes statistical analysis and estimation to provide knowledge of the conditions. Trains operating along the line utilize these techniques to understand inputs into their SBD calculation. This provides for a SBD calculation on board the train that is the shortest possible that maintains the required level of safety. The new SBD is a prime determinant in systems capacity. Therefore by optimizing SBD as describes, system capacity is also optimized. The system continuously adjusts to changing conditions.


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