The grade of automation in railway systems and a fail safe line intrusion detection system for semi-automatic metro lines

The facilitation and acceleration of transportation as a means of modern cities has led to the spread of systems such as the metro. The heavy passenger load and punctual operating concept have made metro line operation critical. This is an imperative for passengers to be safe and comfortable and all precautions must be taken. According to the level of automation that the operation has, these measures are shaped. In this thesis study, firstly the effects of automation and human factors on the operation of rail systems are explained and a line intrusion detection system designed to minimize the effects of accidents or suicides which may be on a subway line with a driver has been emphasized. In Chapter 1, a general literature review is carried out and briefly addressed the purpose of the work and the thesis that might be related to the subject. Moreover, it is stated that this thesis study is an academic aspect and will respond to a need in the sector. In Chapter 2, the location of subway lines in the rail system is given and basic information about subway signaling systems is also given. In this context, the general structure is explained and focused on moving block structure. The components of signal systems in terms of internal dynamics and principles that moving block structure has summarized briefly. In Chapter 3, rail system automation levels are defined and specific characteristics of these levels are mentioned. The security measures taken for each level are explained and it has been shown that these measures actually depend on the increase in the automation level. How to arrange the emergency scenarios is described in the driver and driverless operation specific. The basic concepts of driverless subway lines mentioned in IEC 62290 are given and the advantages and disadvantages of these subways are compared. Explanations have been made about the increase of automation level in the existing subway lines. In addition, it is stated that the subway line intrusions are big problem. Measures that can be taken due to loss of life and material damage due to these intrusions have been examined in the light of examples from around the world. In Chapter 4, the general functional safety description is made and general safety parameters are mentioned. In this context, according to IEC 61508 umbrella standard and specific EN standards; risk analysis, fault tree etc. general information about applications are given. In addition, the concept of Safety Integrity Level (SIL) is emphasized and it is explained how systems with critical mitigation should be assessed by the methodology of the risks and risks they have. In addition to these, safety systems have been tried to be shaped according to the preferred design of the industry (1oo2, 2oo3, etc.) and to show the differences in the safety account according to the demand mode of the system. In Chapter 5, for Kadıköy-Kaynarca metro line a fail safe line intrusion detection system is considered and designed in accordance with the metro conditions. At this point, various scenarios were planned and edited according to the manufacturer's declarations for the selected sensors, controllers and other equipment, and flow charts were determined. In addition to detecting the system, the triggers that the system has in the sense of output are specified, and the details of the connection with the signaling system in which the interface is established are mentioned. In Chapter 6, Preliminary hazard prediction of line intrusion detection system is made and found the level of safety integrity (SIL) that the risk graph method should have. Then the fault tree is built and the SIL value of the safety function of the system is found. It is seen that the required value overlaps the found value. Finally, in the conclusion section, the effect of system automation logic and human factor on the operation was taken up again in the direction of findings in the study of thesis. According to this, the general tendency in the world is directed towards the driverless subway which operates at the GoA4 level. Besides this, it is emphasized why driverless metro lines should be preferred. In the same way, the PSD (Platform Separator Door System) and other solutions applied in the world for line intrusions have been compared and evaluated in terms of advantages and disadvantages. Another issue is summarized as to what can be done to reduce the negative effect of line intrusions, which is a big problem even for GoA2 subway lines. Kadıköy-Kaynarca metro line was interpreted as the final result of calculation of the safety integrity for the constructed structure.