China
Africa
Explore chapters and articles related to this topic
Railway bridge asset management using a Petri-Net modelling approach
Published in Jaap Bakker, Dan M. Frangopol, Klaas van Breugel, Life-Cycle of Engineering Systems, 2017
P.C. Yianni, D. Rama, L.C. Neves, J.D. Andrews
The railway network is critical to the UK economic output. Both commuters and freight rely heavily on the network. The pressure on the railway network to increase its throughput is high. A vast increase in throughput is predicted with the introduction of moving block signalling; this means that trains can run closer together with tighter schedules. Coupled with increasingly more powerful tractive units, the stresses on the network will be tremendous. Therefore, more effective management of the assets is required to be able to cope with the increased demand. The focus of this study is civil structures; in particular railway bridges.
EMC in Different Industrial Sectors
Published in Christos Christopoulos, Principles and Techniques of Electromagnetic Compatibility, 2022
We now consider the EMC and interoperability issues arising from communications-based train control systems. Traditional means of train protection and control rely on visual signals and exchange of tokens and are not appropriate in the case of high-speed trains and high-density metropolitan train networks. Moreover, train systems must work seamlessly across national boundaries to ensure interoperability and fast train connections between major urban areas across national borders. Increasingly, traditional schemes are being replaced by communication systems that can give authority for trains to proceed or initiate braking, with or without driver intervention. There are two major communications-based train systems: the communications-based train control (CBTC) and the European Train Control System (ETCS).27 The two systems have many similarities and overlaps, but also some differences. Broadly speaking, CBTC is used in mass transit systems with emphasis on driverless operation, while ETCS is applied mainly in long-haul routes with emphasis on interoperability. Both systems are evolving, and the differences mentioned above are increasingly blurred. One way in which control and protection systems differ is whether they enforce a fixed- or moving-block operation. In the conventional fixed-block operation, the track is divided into sections (typically 1 km long) and only one train is allowed at a time in each section. This is ensured through communications between trackside and train-mounted systems. In contrast, in the moving-block operation, the minimum allowed distance between trains is not fixed, but is determined by train speed and other factors. The latter more dynamic approach allows for a higher train density. As an example, Levels 1 and 2 in ETCS are based on fixed-block operation and Level 3 on moving-block operation. Depending on the choice made, a range of levels of automation may be achieved. Clearly, strict communication protocols are required to achieve the required levels of safely, automation, and interoperability. Standards for communications-based train systems are undergoing a rapid evolution from slow data rates based on 2G to faster rates based on 4G and beyond. Examples are the Global System for Mobile Communications (GSM-R), IEEE 802.11, and the Long Term Evolution (LTE) systems.28–30
Hyperloop transport technology assessment and system analysis
Published in Transportation Planning and Technology, 2020
Automatic traffic control of Hyperloop vehicles, too, would require a minimum safe headway distance similar to an ETCS level 3 moving block system that must guarantee vehicle integrity at any time and respects the minimum time for data processing and communication, the running time over their own braking distance plus a still to be determined safety margin (Figure 4) before they would arrive in front of a (fixed) signal that may transmit a MA only after a route until the first airlock has been set-up. As the interlocking time for the route for passing two airlocks at each terminal station would last much longer than the approach time, the minimum headway time between a pair of Hyperloop vehicles following each other along the tube, the former time governs the transport system throughput (Figure 5).
System model building and dynamic online control of traffic flow
Published in Mathematical and Computer Modelling of Dynamical Systems, 2020
Xiao-Qiong Huang, Yun-Xiang Han
To keep safe train headway throughout the process, the simulation modelled a moving-block signalling system and the transportation network’s configurations remain the same for all scenarios. Table 5 displays the full model parameter values mentioned, which refers to the passenger number. Similarly, Table 6 also refers to a system parameter. Besides, the infrastructure occupation corresponds to the time interval needed to operate trains based on a given timetable incorporating planned running and stopping times.