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A train protection system is a railway technical installation to ensure safe operation in the event of human error. [1]
| | This article needs additional citations for verification .(February 2014) |
A train protection system is a railway technical installation to ensure safe operation in the event of human error. [1]
The earliest systems were train stops, as still used by the New York City Subway, the Toronto subway, the London Underground, the Moscow Subway (only on the older lines) and the Berlin S-Bahn. Beside every signal is a moveable arm. If the signal is red, levers connected to valves on any passing train hit the arm, opening the brake line, applying the emergency brake, If the signal shows green, the arm is turned away from the levers and there is no contact. [2]
The Great Western Railway in the UK introduced its 'automatic train control' system in the early years of the 20th century. Each distant signal had before it a ramp between the running rails. If the signal showed green, the ramp was energised with a low voltage current which was passed to the locomotive when a shoe came into contact with the ramp. A bell rang in the locomotive's cab to confirm the clear aspect, and the electric current kept the brakes from being applied. If the signal showed yellow (meaning the next signal would show red) the ramp was dead and a siren sounded in the cab. If the siren was not cancelled, the brakes would automatically be applied. After the nationalisation of the railways in the UK in 1948, this system was later replaced by the magnetic induction "automatic warning system". [3]
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. Additionally, they often require the driver to confirm distant signals (e.g. CAWS) that show stop or caution – failure to do so results in the train stopping. [5]
More advanced systems (e.g., PZB, and ZUB) calculate a braking curve that determines if the train can stop before the next red signal, and if not they brake the train. They require that the train driver enter the weight and the type of brakes into the onboard computer. One disadvantage of this kind of system is that the train cannot speed up before the signal if it has switched to green because the onboard computer's information can only be updated at the next magnet. To overcome that problem, some systems allow additional magnets to be placed between distant and home signals or data transfer from the signalling system to the onboard computer is continuous (e.g., LZB). [6]
Prior to the development of a standard train protection system in Europe, there were several incompatible systems in use. Locomotives that crossed national borders had to be equipped with multiple systems. In cases where this wasn't possible or practical, the locomotives themselves had to be changed. To overcome these problems, the European Train Control System standard was developed. It offers different levels of functionality, ranging from simple to complex. This model allows adopters to meet the cost and performance requirements of disparate solutions, from the smallest to the largest. The European system has been in operation since 2002 and uses GSM digital radio with continuous connectivity.
The newer systems use cab signalling, where the trains constantly receive information regarding their relative positions to other trains. The computer shows the driver how fast they may drive, instead of them relying on exterior signals. Systems of this kind are in common use in France, Germany and Japan, where the high speeds of the trains made it impossible for the train driver to read exterior signals, and distances between distant and home signals are too short for the train to brake.
These systems are usually far more than automatic train protection systems; not only do they prevent accidents, they also actively support the train driver and detect blind spots around trains. Some systems are able to drive the train nearly automatically.
| System | Country |
|---|---|
| ACSES | United States of America |
| ALSN | Russian Federation, Belarus, Estonia, Latvia, Lithuania, Ukraine |
| ASFA | Spain |
| ATB | Netherlands |
| ATC | Sweden, Denmark, Norway, Brazil, South Korea, Japan, Australia (Queensland), United Kingdom |
| ATCS | United States of America |
| ATACS | Japan |
| ATP | United Kingdom, United States of America, Brazil, Australia (Queensland), Hong Kong, Indonesia, Ireland, Dominican Republic, Denmark |
| AWS | United Kingdom, Queensland, South Australia |
| BACC-RS4 Codici /-SCMT | Italy |
| CAWS | Ireland |
| CBTC | Brazil, United States of America, Canada, Singapore, Spain, Gabon, Hong Kong, Indonesia, Denmark, United Kingdom |
| CONVEL | Portugal |
| Crocodile/Memor | Belgium, France |
| CTCS | China |
| EBICAB | Bulgaria, Finland, Norway, Portugal, Spain, Sweden |
| EVM 120 | Hungary |
| HKT | Denmark |
| I-ETMS | United States of America |
| Integra-Signum | Switzerland |
| ITARUS-ATC | Russian Federation |
| ITCS | United States of America |
| Kavach | India |
| KLUB | Russian Federation |
| KVB | France |
| LKJ 2000 | China, Ethiopia |
| LS | Czech republic, Slovakia |
| LZB | Germany, Austria, Spain |
| PTC | United States of America |
| PZB Indusi | Germany, Indonesia, Austria, Romania, Slovenia, Croatia, Bosnia-Herzegovina, Serbia, Montenegro, Macedonia, Israel, United Kingdom |
| SACEM | France, Hong Kong |
| SHP | Poland |
| TASC | Japan |
| TBL | Belgium, Hong Kong |
| TPWS | United Kingdom, Victoria |
| TVM | High speed lines in: France, Belgium, United Kingdom, Channel Tunnel, South Korea |
| VEPS | Estonia |
| ZUB 123 | Denmark |
| ZUB 262 | Switzerland |
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. If it is not, ATP activates an emergency brake to stop the train.
The Train Protection & Warning System (TPWS) is a train protection system used throughout the British passenger main-line railway network, and in Victoria, Australia.
A balise is an electronic beacon or transponder placed between the rails of a railway as part of an automatic train protection (ATP) system. The French word balise is used to distinguish these beacons from other kinds of beacons.
Automatic Warning System (AWS) is a railway safety system invented and predominantly used in the United Kingdom. It provides a train driver with an audible indication of whether the next signal they are approaching is clear or at caution. Depending on the upcoming signal state, the AWS will either produce a 'horn' sound, or a 'bell' sound. If the train driver fails to acknowledge a warning indication, an emergency brake application is initiated by the AWS. However if the driver correctly acknowledges the warning indication by pressing an acknowledgement button, then a visual 'sunflower' is displayed to the driver, as a reminder of the warning.
Cab signaling is a railway safety system that communicates track status and condition information to the cab, crew compartment or driver's compartment of a locomotive, railcar or multiple unit. The information is continually updated giving an easy to read display to the train driver or engine driver.
Automatic train control (ATC) is a general class of train protection systems for railways that involves a speed control mechanism in response to external inputs. For example, a system could effect an emergency brake application if the driver does not react to a signal at danger. ATC systems tend to integrate various cab signalling technologies and they use more granular deceleration patterns in lieu of the rigid stops encountered with the older automatic train stop (ATS) technology. ATC can also be used with automatic train operation (ATO) and is usually considered to be the safety-critical part of a railway system.
A crocodile is a component of train protection systems used in France and Belgium. It works similarly to the Automatic Warning System (AWS) used in the United Kingdom.
Automatic train stop or ATS is a system on a train that automatically stops a train if certain situations occur to prevent accidents. In some scenarios it functions as a type of dead man's switch. Automatic train stop differs from the concept of Automatic Train Control in that ATS usually does not feature an onboard speed control mechanism.
Linienzugbeeinflussung is a cab signalling and train protection system used on selected German and Austrian railway lines as well as on the AVE and some commuter rail lines in Spain. The system was mandatory where trains were allowed to exceed speeds of 160 km/h (99 mph) in Germany and 220 km/h (140 mph) in Spain. It is also used on some slower railway and urban rapid transit lines to increase capacity. The German Linienzugbeeinflussung translates to continuous train control, literally: linear train influencing. It is also called linienförmige Zugbeeinflussung.
PZB or Indusi is an intermittent cab signalling system and train protection system used in Germany, Austria, Slovenia, Croatia, Romania, Israel, Serbia, on two lines in Hungary, on the Tyne and Wear Metro in the UK, and formerly on the Trillium Line in Canada.
Transmission Voie-Machine is a form of in-cab signalling originally deployed in France and is mainly used on high-speed railway lines. TVM-300 was the first version, followed by TVM-430.
Railway signals in Germany are regulated by the Eisenbahn-Signalordnung. There are several signalling systems in use, including the traditional H/V (Hauptsignal/Vorsignal) system.
Integra-Signum is a Swiss train protection system introduced in 1933. Originally it was called Signum; the name Integra was added later. It transmits data inductively and is simple, robust and reliable also in snow.
The Deutsche Reichsbahn Class 250 is a German electric locomotive used on freight trains. It is nicknamed the "Electric Container" or "Powercontainer" due to its distinctive carbody shape. It was the most powerful locomotive in the former GDR and is still in use with Deutsche Bahn AG.
Advanced Civil Speed Enforcement System (ACSES) is a positive train control cab signaling system developed by Alstom. The system is designed to prevent train-to-train collisions, protect against overspeed, and protect work crews with temporary speed restrictions. The information about permanent and temporary speed restrictions is transmitted to the train by transponders (Balises) lying in the track, coded track circuits and digital radio. It was installed beginning in 2000 on all of Amtrak's Northeast Corridor between Washington and Boston, and has been fully active since December 2015, a few months after the 2015 Philadelphia train derailment which it would have prevented.
EBICab is a trademark registered by Alstom for the equipment on board a train used as a part of an Automatic Train Control system. Three different families exist, which are technically unrelated.
The Chinese Train Control System is a train control system used on railway lines in People's Republic of China. CTCS is similar to the European Train Control System (ETCS).
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 ZUB 1xx system is a family of train protection systems produced by Siemens. Its ZUB balises were deployed in the ZUB 121 train protection system in the Swiss railway network, in the ZUB 122 tilting control system in the German railway network, and in the ZUB 123 train protection system in the Danish railway network. Some of these were adapted for other railway lines before the next generation ZUB 2xx family was introduced which is based on Eurobalises - the earlier ZUB balises are not compatible with those.