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Double Line Automatic Signalling is a form of railway signalling used on the majority of double line sections in New Zealand. Double Line Automatic Signalling uses track circuits to detect the presence of trains in sections broken up by intermediate signals. Usually there is an 'up' and a 'down' main line, and beyond station limits the lines are not bi-directionally signalled. DLAS is not designed for wrong-line running in emergency situations. [1]
At junctions or points, one of or both mains signals are usually controlled either remotely (by a Train Controller or Signalmen) or switched in at a local panel.
Sidings off one or both mains are usually operated by switchlock lever points secured by padlock and track circuit presence that enables a release to be given before points can be operated.
A railroad switch (AE), turnout, or [set of] points (BE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
A railway signal is a visual display device that conveys instructions or provides warning of instructions regarding the driver’s authority to proceed. The driver interprets the signal's indication and acts accordingly. Typically, a signal might inform the driver of the speed at which the train may safely proceed or it may instruct the driver to stop.
On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timetable. Signalling control was originally exercised via a decentralised network of control points that were known by a variety of names including signal box, interlocking tower and signal cabin. Currently these decentralised systems are being consolidated into wide scale signalling centres or dispatch offices. Whatever the form, signalling control provides an interface between the human signal operator and the lineside signalling equipment. The technical apparatus used to control switches (points), signals and block systems is called interlocking.
Railway signalling (BE), also spelled railway signaling (AE), is a system used to direct railway traffic and keep trains clear of each other at all times. Trains move on fixed rails, making them uniquely susceptible to collision. This susceptibility is exacerbated by the enormous weight and momentum of a train, which makes it difficult to quickly stop when encountering an obstacle. In the UK, the Regulation of Railways Act 1889 introduced a series of requirements on matters such as the implementation of interlocked block signalling and other safety measures as a direct result of the Armagh rail disaster in that year.
In railway signalling, a token is a physical object which a train driver is required to have or see before entering onto a particular section of single track. The token is clearly endorsed with the names of the section it belongs to. A token system is more commonly used for single lines because of the greater risk of collision in the event of a mistake being made by a signaller or traincrew, than on double lines.
The Flemington Racecourse railway line is a commuter rail passenger train service in Melbourne, Australia. The full service operates between Flemington Racecourse in the inner suburb of Flemington and Flinders Street in the central business district. The service is part of the Public Transport Victoria metropolitan rail network.
Centralized traffic control (CTC) is a form of railway signalling that originated in North America. CTC consolidates train routing decisions that were previously carried out by local signal operators or the train crews themselves. The system consists of a centralized train dispatcher's office that controls railroad interlockings and traffic flows in portions of the rail system designated as CTC territory. One hallmark of CTC is a control panel with a graphical depiction of the railroad. On this panel, the dispatcher can keep track of trains' locations across the territory that the dispatcher controls. Larger railroads may have multiple dispatcher's offices and even multiple dispatchers for each operating division. These offices are usually located near the busiest yards or stations, and their operational qualities can be compared to air traffic towers.
A passing loop or passing siding is a place on a single line railway or tramway, often located at or near a station, where trains or trams travelling in opposite directions can pass each other. Trains/trams going in the same direction can also overtake, provided that the signalling arrangement allows it. A passing loop is double-ended and connected to the main track at both ends, though a dead end siding known as a refuge siding, which is much less convenient, can be used. A similar arrangement is used on the gauntlet track of cable railways and funiculars, and in passing places on single-track roads.
A track circuit is an electrical device used to prove the absence of a train on rail tracks to signallers and control relevant signals. An alternative to track circuits are axle counters.
Catch points and trap points are types of turnout which act as railway safety devices. Both work by guiding railway carriages and trucks from a dangerous route onto a separate, safer track. Catch points are used to derail vehicles which are out of control on steep slopes. Trap points are used to protect main railway lines from unauthorised vehicles moving onto them from sidings or branch lines. Either of these track arrangements may lead the vehicles into a sand drag or safety siding, track arrangements which are used to safely stop them after they have left the main tracks.
The railway signalling system used across the majority of the United Kingdom rail network uses lineside signals to control the movement and speed of trains.
Australian railway signalling varies between the states of Australia, because each railway system was established under the different colonial governments with separate legislation. Just as with the notorious variation of Australian rail gauges, there are differing signal systems. The systems in New South Wales generally follow British precedents, although American influence has increased somewhat since the 1990s. Victoria uses American-style speed signalling on its main lines. That can cause confusion where the systems meet.
Signaling and operation on the Washington Metro system involves train control, station identification, train signaling, signage, and train length. As with any working railroad, communication between train operators, dispatchers, station personnel and passengers is critical. Failures will result in delays, accidents, and even fatalities. It is therefore important that a comprehensive signal system operated by a central authority be in place. This gives individual train and station operators the information they need to safely and efficiently perform their tasks.
Signalling block systems enable the safe and efficient operation of railways by preventing collisions between trains. The basic principle is that a track is broken up into a series of sections or "blocks". Only one train may occupy a block at a time, and the blocks are sized to allow a train to stop within them. That ensures that a train always has time to stop before getting dangerously close to another train on the same line. The block system is referred to in the UK as the method of working, in the US as the method of operation, and in Australia as safeworking.
The 8.38 miles (13.49 km) Tawa Flat deviation is a double-track section of the Kapiti Line just north of Wellington, New Zealand with two tunnels; the southernmost section of the North Island Main Trunk railway (NIMT) between Wellington and Auckland. It was built to bypass a limited capacity single track section of the original Wellington and Manawatu Railway (WMR) line which ascended from Wellington to Johnsonville and then descended to Tawa Flat. The original name of Tawa Flat was changed to Tawa in 1959.
Kaiwharawhara railway station, a former railway station on the North Island Main Trunk and the Wairarapa Line in Wellington in New Zealand, closed in 2013. It was the first station north of Wellington, serving the early suburb of Kaiwharawhara. Prior to its closure it was served by trains operated by Tranz Metro as part of the Metlink network on the Melling Line, the Hutt Valley Line and the Kapiti Line.
The Great Cockcrow Railway is a 7+1⁄4 in gauge miniature railway located near Chertsey, Surrey, UK. It is usually open on Sunday afternoons from May to October inclusive.
Automatic block signaling (ABS), spelled automatic block signalling or called track circuit block (TCB) 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. ABS operation is designed to allow trains operating in the same direction to follow each other in a safe manner without risk of rear-end collision.
The first railway signalling in Greece was installed on the Athens–Piraeus Railway at the turn of the 20th century, when semaphores and boards were added with the line's electrification. Other Greek trains at that time were controlled by signals given manually by station masters. During World War II, German occupation forces installed mechanically operated semaphore signals at the entrance to all stations, with some light signals at busy stations. Modern signalling is provided through colour light signals. Radio communication between train stations and drivers was introduced in 1973 and digital communication is an ongoing present-day introduction.
The application of railway signals on a rail layout is determined by various factors, principally the location of points of potential conflict, as well as the speed and frequency of trains and the movements they require to make.