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29-481: It has two subsystems: ground subsystem and onboard subsystem. The ground subsystem may based on balise , track circuit , radio communication network ( GSM-R ), and Radio Block Center (RBC). The onboard subsystem includes onboard computer and communication module. There consists of 5 different levels (Level 0 to Level 5). Levels 2, 3, and 4 are back-compatible with lower levels. For railway lines where operational speeds are below 120 km/h (75 mph): Level 0

58-515: A more accurate supplement to GPS , to enable safe operation of automatic selective door opening . The balise is typically mounted on or between sleepers or ties in the centre line of the track. A train travelling at maximum speed of 500 km/h (310 mph) will transmit and receive a minimum of three copies of the telegram while passing over each Eurobalise. The earlier KER balises (KVB, EBICAB, RSDD) were specified to work up to 350 km/h (220 mph). The train's on-board computer uses

87-478: A passing train, for in cab display. If the trains control system failed to receive an update, within 1km of the last signal, the displayed speed limit would be blanked an audio tone the driver had to respond to generated, else the trains brakes were automatically applied, the system would be see revenue service from December 1981, with the introduction of the British Rail Class 370 . The development of

116-619: 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. Balises are used in the KVB signalling system installed on main lines of the French railway network, other than the high-speed Lignes à Grande Vitesse . Balises constitute an integral part of the European Train Control System , where they serve as "beacons" giving

145-440: A redundant system to CTCS-3. Train positions can be accurately calculated using balises and onboard odometers which are transmitted to Radio Block Centres (RBCs). Authorisation of train movement is created by RBCs and transmitted onto on-board cab equipment using GSM-R. Using both trackside equipment and onboard equipment, ATP can be achieved. Trackside signalling is not mandatory and can be replaced with cab signalling using DMI. It

174-518: A result, the LZB system was not only used on high-speed tracks but also in commuter rail to increase throughput. Due to the deployment costs of the system however it was restricted to these application areas. During the 1970s British Rail developed the C-APT, the system utilised passive transponders (balises) placed at no more than 1km track intervals, that would transmit the track speed (in an 80bit packet) to

203-462: A stop signal but due to excessive speed still crashed despite the automatic stop. Multiple systems were invented to show the speed in the driver's cab and to provide an electronic system on the train that would prevent speeding. With the advent of high-speed trains it was generally expected that a speed indicator on line-side signals is not sufficient beyond 160 km/h (99 mph) so that all these trains need cab signalling . A combined solution to

232-691: A successor to the PZB signalling that was deployed as ZUB 121  [ de ] in Switzerland since 1992 and ZUB 123  [ de ] in Denmark since 1992. ABB improved the external balises in the EBICAB 900 system which as then adopted in Spain and Italy. Siemens had presented a study on balise systems in 1992 which influenced the choice of using a technology based on KVB and GSM instead of LZB when

261-540: A system using the principle of passive balises with fixed or controlled information started in 1975 by LMEricson and SRT, following an incident in Norway in 1975 (Tretten). The LME/SRT system became the Ebicab system. The Ebicab system established the principles of using magnetic coupling, 27 MHz downlink from the antenna on the locomotive to energize the balises, and an uplink using 4,5 MHz to transmit information telegrams from

290-439: A train passing at any speed up to 500 km/h. A balise may be either a 'Fixed Data Balise', or 'Fixed Balise' for short, transmitting the same data to every train, or a 'Transparent Data Balise' which transmits variable data, also called a 'Switchable' or 'Controllable Balise'. (Note that the word 'fixed' refers to the information transmitted by the balise, not to its physical location. All balises are immobile). A fixed balise

319-435: Is called a Eurobalise . A balise typically needs no power source. In response to radio frequency energy broadcast by a Balise Transmission Module mounted under a passing train, the balise either transmits information to the train ( uplink ) or receives information from the train ( downlink , although this function is rarely used). The transmission rate of Eurobalises is sufficient for a complete 'telegram' to be received by

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348-408: Is connected to a Lineside Electronics Unit (LEU), which transmits dynamic data to the train, such as signal indications. Balises forming part of an ETCS Level 1 signalling system employ this capability. The LEU integrates with the conventional (national) signal system either by connecting to the lineside railway signal or to the signalling control tower. Balises must be deployed in pairs so that

377-602: Is considered to be a "quasi-moving-block" system. This is currently in use for all of the 200–250 km/h (120–160 mph) lines on China's high-speed railway system , with a backup system of CTCS-2. CTCS-3 is equivalent to ETCS-2 . It would feature the complete elimination of track circuits , moving blocks and self-train-integrity-check, which would significantly reduce the number of conventional track signalling equipment needed. Train integrity would be completely detected entirely through CTCS-3. Data transmission would be performed on GSM-R or LTE-M . Trackside signalling

406-439: Is enabled on CTCS level 1. Drivers use cab signals as primary signals. Train circuits are responsible for detecting track occupancy and integrity. Temporary speed restrictions, train positions and track data are provided intermittently. For high-speed railways where operational speeds are below 250 km/h (160 mph): The track circuit is used both for train occupation detection and movement authorization, its architecture

435-454: Is not mandatory and can be replaced with cab signalling using DMI. Currently, Level 4 is not in use on any tracks and exists only as a conceptual system equivalent to ETCS-3 . It is being developed and defined by signalling manufacturers in China. Balise A balise ( / b ə ˈ l iː z / bə- LEEZ ) is an electronic beacon or transponder placed between the rails of

464-460: Is programmed to transmit the same data to every train. Information transmitted by a fixed balise typically includes: the location of the balise; the geometry of the line , such as curves and gradients; and any speed restrictions. The programming is performed using a wireless programming device. Thus a fixed balise can notify a train of its exact location, and the distance to the next signal, and can warn of any speed restrictions. A controllable balise

493-554: Is similar to TVM-300 . Balises and track circuit serves to provide intermittent trackside information and automatic train protection (ATP) to cab equipment. Trackside signalling is not mandatory and can be replaced with cab signalling using DMI. LKJ can be equipped as redundancy on CTCS-0 lines. Minimum headways on CTCS-2 is 180 seconds. This system is compatible with ETCS-1 . For high-speed railway of above 250 km/h (160 mph): CTCS-3 introduces GSM-R radio for bidirectional data transmission . Track circuits are used as

522-613: Is used on lines with conventional trackside signalling. Train drivers follow trackside signals primarily, with cab signals as back-up. UCS receives train fixed block occupation signals from track circuits and is shown as cab signals using digital signal processes. TOSU/LKJ is used to supervise speed limits and can only advise train drivers on braking curves. The drives are mainly responsible for maintaining train speed protection. For railway lines where operational speeds are below 160 km/h (99 mph): Balises are installed in addition to track circuits. Automatic train protection (ATP)

551-698: The European Rail Traffic Management System was researching a possible train signalling for Europe. The first Eurobalises were tested in 1996 and later train protection systems used them as a basis for their signalling needs. Contr%C3%B4le de vitesse par balises Contrôle de Vitesse par Balises ( Speed control by beacons ) , abbreviated to KVB is a train protection system used in France and in London St. Pancras International station . It checks and controls

580-674: The Flaujac crash in 1985 and the 1991 Melun rail crash. Every locomotive unit on the French national railway network , except those that operate connected to other locomotives, must be equipped with this system. More than 5,000 engines, including foreign locomotives that travel within France, are equipped. The TGV is equipped with this system for all of its routes over conventional rail lines. A European system for train control, called ETCS , will replace this and many other diverse systems in

609-485: The ERTMS ETCS balises. During the 1980s, other cab computers were introduced to read the older signalling and to overlay it with better control. The German PZ80 was able to check the speed in steps of 10 km/h (6.2 mph). The French KVB replaced the external system with balises in the early 1990s to transmit a combined information for oncoming signal aspects and the allowed train speed. Siemens did also invent

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638-507: The balises. The controlled information in the balises is encoded from statuses in the signalling system. The telegrams contains information about permitted speeds, and distances. The information is used in the on-board computer to calculate brake curves, monitor speed and eventually apply brakes. In Norway, the first line equipped with Ebicab as ATP was operational in 1983. The Ebicab principles are subsequently used in KVB and RSDD systems and also for

667-446: The data from the balises to determine the safe speed profile for the line ahead. Enough information is needed to allow the train to come to a safe standstill if required. The data in the balise can include the distance to the next balise. This is used to check for missing balises which could otherwise lead to a potential wrong-side failure . At the start and end of ATP-equipped territory, a pair of fixed balises are often used to inform

696-630: The exact location of a train. The ETCS signalling system is gradually being introduced on railways throughout the European Union . Balises are also used in the Chinese Train Control System versions CTCS-2 and CTCS-3 installed on high-speed rail lines in China, which is based on the European Train Control System . A balise which complies with the European Train Control System specification

725-411: The onboard ATP equipment to start or stop supervision of the train movements. Eurobalises are used in: Balises other than Eurobalises are used in: The earliest automatic train protection system were purely mechanical with a tripcock which could be connected directly to the braking system by releasing the opening a switch in the hydraulic system. There were multiple incidents where trains had overrun

754-506: The requirements was the German LZB system that was presented in 1965. The original installations were all hard-wired logic. The first real cab electronics was presented in 1972 (named LZB L72) and a cab computer was introduced by 1980 (LZB 80). The LZB system uses a wire in the middle of the tracks that had loops at a distance of 100 m (330 ft) so that the position of a train was known more precisely than in any earlier system. As

783-426: The speed of moving trains. KVB consists of: The on-board computer generates two speed-thresholds based on the received signals from the balises. If the train is over the speed limit, passing the first speed-threshold, an audible alarm sounds and the control panel indicates to the driver to adjust the train speed without delay. If the second speed threshold is passed, the KVB automatically engages emergency brakes on

812-437: The train can distinguish the direction of travel 1→2 from direction 2→1, unless they are linked to a previous balise group in which case they can contain only one balise. Extra balises can be installed if the volume of data is too great. Balises operate with equipment on the train to provide a system that enhances the safety of train operation: at the approaches to stations with multiple platforms fixed balises may be deployed, as

841-529: The train. The system is an adaptation of a similar system that was used in Sweden , which uses an Intel 8085 microprocessor . The first generation French KVB also used this technology. The next revisions evolved towards a Motorola 68020 processor and the software was re-written using the B-Method . The decision to implement this technology was made at the beginning of the 1990s following accidents such as

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