Optimization of railway systems design and test processes

Rail systems have become increasingly important systems to make investment by the countries since these systems offer economic and rapid solutions for the passenger and freight transport. In terms of design, there are different varieties such as open lines, subways, trams and suburbs which differ in the technologies used by these different systems. Rail systems providing solutions according to local and inter-city needs are required to provide a certain level of safety. This level is generally on top of technological systems, because accidents in rail systems can cause loss of life and property in very large sizes. While these safety levels are provided by various systems, interlocking systems, which are the ground base of these architectures. In this thesis, one of the elements taken as the basis of the interlocking design in a rail system project is discussed with reference to the criteria discussed in the design and testing processes. The functions of the interlocking in the basic architecture are mentioned in the main interconnection and auxiliary interlocking communication systems. Its working rules and integration with the CBTC or ERTMS system are mentioned. Some improvement measures are made in order to prevent negative effects on the test processes as much as possible. Also, some technical measures have been taken in the frequent planning of the rail system project. During the test processes that have different purposes, it has been explained that what is targeted in rail systems and how to perform a good test process. It is also mentioned that how to achieve a time optimization by minimizing the impact of the test processes on the problems that may be encountered during the assembly phase of the line. Proposed methods and improvements have been discussed related to newly constructed lines that how would be integrated these lines to existing lines that are still continue operation. For this issue, it is discussed not only for the problems that may occur during the assembly phase but also mitigate the risks for the projects that have working lines. A simulation procedure that is proposed for use in the improvement of the test processes allow the necessary manipulations to be communicated in the field with the actual interlocking. This simulation procedure can provide the duty of interlocking modules with hardware and software simulations. In other words, general working structure of interlocking could be obtained with this method. Application scenarios explained how these simulations can be used effectively. There are different kind of elements such as signals, track circuits, point machines etc. For all these elements, there is a possibility that not having them ready on the site because of some internal or external reasons. These missing points are going to affect integrity of the tests that going to be applied. For the installation missing items which would be potentially big problem, optimal solution is that test procedures should be isolated from these problems as much as possible. Even if the system is not completely ready, progress of testing software, interlocking hardware equipment can continue and identifying the problems can be possible. Moreover, because of interlocking rules, it is normally not possible to have tests if some of the equipment are not ready. In this case, adjacent main interlockings need to be ready for whole of the line in terms of installation and software design, which is not possible in many cases. If track circuit installations, cantilever signal installations or point machines status or emergency buttons installation or their assigned software is not properly configured, it is not going to affect testing directly at least for other elements. For example, even if specific part of the line has no problem, however, its relevant parts such as other directions and crossings having problems according to interlocking rules, test requirements will not be fulfilled. Another aim of this thesis is to propose an improvement method in the integration of other lines to the systems where there is a working line. Normally, the connection of a working line with other stations, communication, interception of interlocking software stops the operation of the line is done when the line is not working. Considering that the first train daily in the morning checks the running line and the evening operation continues until midnight, the tests of the equipment in the lines can be carried out only at night-time in several hours. This greatly reduces the efficiency of the tests and makes determination of the possible problems very difficult. Since the main interconnections are made and they are working according to a specific software version, in the night test, all interlocking software must be installed, and current tests should be started and then the old software must be switched in order to return to daily operation. These processes take a long time and bring the possibility not be able to use the system for daily operation. The proposed improvement in this thesis is a simulation program that can run on the main interlocking software. Using this program, the auxiliary interlockings that receive the information of the equipment of the new lines communicate with the main interlocks running the new software. Thus, it eliminates the necessity of changing the software of the main interlocking of the line in the testing processes. It also allows the tests to be performed during day instead of at night, minimizing the possibility of negatively affecting the operation and increasing the efficiency. It can be demonstrated not only to ensure the testing of the interlocking system, but also to reveal the assembly problems. Because of the fact that each of the equipment is tested individually, the problems caused by the wrong hardware can be identified. It also plays a role in identifying potential problems that may arise from Automatic Train Supervision ("ATS") by testing the processes that normally could not be tested. In case of possible incompatibility of interlocking with ATS, mis defined equipment may be detected in ATS. In addition to these corrections, potential problems that may arise in interface can be identified. Thanks to the improvements made, it is possible to find out whether there is a problem with ATS in the avaliable routes so that visual interface problems can be solved. In addition, the effects of data monitoring procedures on test processes and methods for problem solving are discussed. It is easier to determine whether the malfunctions occurring in the test processes by hardware or software. These malfunctions are detected by the method of filtering the bit transitions that can observe by data monitoring methods. Thus, the intended improvements are achieved in both the design and test processes. Thanks to that improvements, project completion process will be more uninterrupted and sustainable.