Search results
Results from the WOW.Com Content Network
Block systems are used to control trains between stations and yards, but not normally within the yards, where some other method is used. Any block system is defined by its associated physical equipment and by the application of a relevant set of rules. Some systems involve the use of signals while others do not.
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.
Absolute block signalling is a British signalling block system designed to ensure the safe operation of a railway by allowing only one train to occupy a defined section of track (block) at a time. [1] Each block section is manually controlled by a signalman, who communicates with the other block sections via telegraph.
In railway signalling, a moving block is a signalling block system where the blocks are defined in real time by computers as safe zones around each train. This requires both knowledge of the exact location and speed of all trains at any given time, and continual communication between the central signalling system and the train's cab signalling ...
Fixed mechanical signals began to replace hand signals from the 1830s. These were originally worked locally, but it later became normal practice to operate all the signals on a particular block with levers grouped together in a signal box. When a train passed into a block, a signalman would protect that block by setting its signal to 'danger ...
The US and Canada departed from UK practice wherein a semaphore blade is devoted to each route (Route Signaling). General North American practice is to group routes by speeds and use a single blade for, say, "medium speed" regardless of the number of routes involved (Speed Signaling). The primary exception to this situation is in the field of ...
CITYFLO 650 signalling is a CBTC system designed by Bombardier Transportation and later Alstom.It makes use of bi-directional radio communication between trains and wayside equipment, as well as true moving block technology, to control train operation.
Each block has a receiver at the opposite end to the transmitter, and the loss of the track circuit signal (owing to shorting by train wheels or due to a failure) is interpreted as an indication that the block is occupied. Signalling block boundaries are equipped with electrical separation joints that prevent adjacent blocks from interfering ...