Rame inox de banlieue - KVB sur le pupitre de conduite

(''Speed control by beacons''), abbreviated to KVB is a

train protection system A train protection system is a railway technical installation to ensure safe operation in the event of human error. Development Train stops The earliest systems were train stops, as still used by the New York City Subway, the Toronto rapid ...

used in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

and in London St. Pancras International station. It checks and controls the speed of moving trains. KVB consists of: *The on-board installation, known as (aboard), which comprises: **An on-board computer (UEVAL) containing a processor, a communication unit and recording equipment **A visual interface for the use of the driver, which ***permits data entry regarding the train's speed, length and category. ***displays information about the state of the system. It does not replicate trackside signals for the driver (for example, the speed limits are not indicated). This is because the KVB is a train protection system, not a cab-signalling system. **An antenna, placed under the locomotive, to receive information sent by the ground installations. *The ground-based or (ground) installations, made up of: **Beacons or

balise 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. Bali ...

s - digital or analogue transponders placed between the two track rails. These can be fixed beacons (sending a single set of information, e.g. placed at a point where there is a change of speed limit) or switchable beacons (sending a variety of messages, so that one signal can send different sets of information as required). **A coder used as an interface between the existing signal and the switchable beacons. 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 the train. The system is an adaptation of a similar system that was used in

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

, which uses an

Intel 8085 The Intel 8085 ("''eighty-eighty-five''") is an 8-bit microprocessor produced by Intel and introduced in March 1976. It is software-binary-code compatibility, binary compatible with the more-famous Intel 8080. It is the last 8-bit microprocesso ...

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

. The first generation French KVB also used this technology. The next revisions evolved towards a

Motorola 68020 The Motorola 68020 is a 32-bit microprocessor from Motorola, released in 1984. A lower-cost version was also made available, known as the 68EC020. In keeping with naming practices common to Motorola designs, the 68020 is usually referred to as t ...

processor and the software was re-written using the

B-Method The B method is a method of software development based on B, a tool-supported formal method based on an abstract machine notation, used in the development of computer software. Overview B was originally developed in the 1980s by Jean-Raymond Abr ...

. The decision to implement this technology was made at the beginning of the 1990s following accidents such as the Flaujac crash in 1985 and the 1991

Melun Melun () is a commune in the Seine-et-Marne department in the Île-de-France region, north-central France. It is located on the southeastern outskirts of Paris, about from the centre of the capital. Melun is the prefecture of Seine-et-Marne, ...

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 The TGV (; , , 'high-speed train') is France's intercity high-speed rail service. With commercial operating speeds of up to on the newer lines, the TGV was conceived at the same period as other technological projects such as the Ariane 1 rocke ...

is equipped with this system for all of its routes over conventional rail lines. A European system for train control, called

ETCS The European Train Control System (ETCS) is a train protection system designed to replace the many incompatible systems used by European railways, and railways outside of Europe. ETCS is the signalling and control component of the European ...

, will replace this and many other diverse systems in the various member states of the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

. KVB is comparable to ETCS Level 1 Limited Supervision because it offers a beacon-based speed control without any indication for the driver.

Notes

References

External links

*
Page about the KVB and the Crocodile
* (PDF
Lines in France equipped with KVB
2009 *
Avis du conseil général des ponts et chaussées
2008 *
Bilan LOTI du KVB
2008 {{DEFAULTSORT:Controle de vitesse par balises

Railway signalling in the United Kingdom Train protection systems