Search results
Results from the WOW.Com Content Network
Automatic block signaling (ABS), spelled automatic block signalling or called track circuit block (TCB [1]) in the UK, is a railroad communications system that consists of a series of signals that divide a railway line into a series of sections, called blocks. The system controls the movement of trains between the blocks using automatic signals.
This is a system for use on single track railways, which requires neither the use of tokens nor provision of continuous train detection through the section. The signalling is designed in such a way that the controlling signals will only allow one train to enter the line at any one time.
ATP switchboard in a Taiwan Railways Administration DR2700 series carriage Automatic Train Protection notice on a First Great Western InterCity 125. Automatic train protection (ATP) is the generic term for train protection systems that continually check that the speed of a train is compatible with the permitted speed allowed by signalling, including automatic stop at certain signal aspects.
The token system is still regularly used on the present-day State Railway of Thailand system. Although most use occurs in regional areas, some use appears in the capital city, Bangkok, such as the Makkasan to Khlong Tan section etc. [16] Sri Lanka Railways uses a tablet exchanging system on the up-country railway line.
A rail break between the insulated rail joint and the track circuit feed wiring would not be detected. Failure modes that result in an incorrect "track clear" signal (known usually in North America as a "false clear") may allow a train to enter an occupied block, creating the risk of a collision. Wheel scale and short trains may also be a problem.
TPWS was developed by British Rail and its successor Railtrack, following a determination in 1994 that British Rail's Automatic Train Protection system was not economical, costing £600,000,000 equivalent to £979,431,929 in 2019 to implement, compared to value in lives saved: £3-£4 million (4,897,160 - 6,529,546 in 2019), per life saved, which was estimated to be 2.9 per year.
In 1906, the Great Western Railway in the UK developed a system known as "automatic train control". In modern terminology, GWR ATC is classified as an automatic warning system (AWS). This was an intermittent train protection system that relied on an electrically energised (or unenergised) rail between, and higher than, the running rails.
In inductive system, data is transmitted magnetically between the track and locomotive by magnets mounted beside the rails and on the locomotive. [4]In the Integra-Signum system the trains are influenced only at given locations, for instance whenever a train ignores a red signal, the emergency brakes are applied and the locomotive's motors are shut down.