Le Crocodile

Le Crocodile

The French (SNCF), Belgian (NMBS/SNCB) and Luxemburger (CFL) railways use an train protection system more or less equal to the British Automatic Warning System (AWS), called the Répétition du Signal en Cabine (French for "Signal Repetition in Driver's Cab").

The signal repetition is done by the crocodile, an electrical contact placed between the rails (in the four-foot or 1.22m way) to provide warnings in the locomotive cab. It is distinctively French, originating on the Chemins de Fer du Nord around 1872, spreading throughout France and penetrating even into Belgium and Luxembourg after 1900. It was intended principally to provide evidence of the alertness of the driver, not to act to control a train automatically. Contact is made with a metallic brush mounted beneath an engine passing over it.

The crocodile is an invention of the engineers Lartigue and Forest. Originally it was placed 100-200 metres in rear of a distant signal, usually a red disc of "deferred stop".When recording of cab signals was introduced, the crocodile was moved closer to the signal, often directly opposite it, to reduce the chance of a change of the signal between the time the locomotive passed over the crocodile and when the locomotive actually passed the signal. If a signal changed suddenly to a warning aspect in the face of the driver, it would appear that he had not noticed it and had been surprised, when that was not the case.

The crocodile can send two different pieces of information to the driver, according to the aspect of the corresponding signal:

- the "Répétition Signal Fermé" ("which literally means:" repetition of closed (=on) signal), corresponding to a warning signal, applies a +20V voltage to the crocodile and sounds a horn in the driver's cab. Then unless the driver presses a button within 5 seconds, a penalty brake is applied.

- the "Répétition Signal Ouvert" ("which literally means:" repetition of opened (=off) signal), corresponding to a cleared signal, applies a -20V voltage to the crocodile and sounds a gong in the driver's cab.

ee also

* Train protection system

External links

* [http://www.carreweb.fr/dsp/kvbrsc.html Page about the Crocodile and the KVB train protection system "(in French)"]
* [http://www.du.edu/~jcalvert/railway/croco.htm#Croc An introduction to French cab signals and speed recorders]


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • crocodile — [ krɔkɔdil ] n. m. • 1538; cocodrille XIIe; lat. crocodilus, gr. krokodeilos 1 ♦ Grand reptile amphibien (crocodiliens) des rivières tropicales et équatoriales, au museau large et long (par opposition au gavial et à l alligator); abusivt Tout… …   Encyclopédie Universelle

  • Crocodile attack — Crocodile attacks on people are common in places where large crocodiles are native and human populations live. Only six of the 23 crocodilian species are considered dangerous to adult humans, and only individuals 2 metres (6.6 ft) in length… …   Wikipedia

  • Crocodile (animal) — Crocodile Pour les articles homonymes, voir Crocodile (homonymie) …   Wikipédia en Français

  • Crocodile shark — Conservation status Near Threatened  …   Wikipedia

  • Crocodile (song) — Crocodile Single by Underworld from the album Oblivion with Bells Released …   Wikipedia

  • "Crocodile" Dundee — Theatrical release poster Directed by Peter Faiman Produced by John Cornell …   Wikipedia

  • Crocodile cracking — Crocodile cracking, also called fatigue cracking or alligator cracking, is a common type of distress in asphalt pavement. It is usually studied under the transportation section of civil engineering. Crocodile cracking is characterized by… …   Wikipedia

  • Crocodile Lake National Wildlife Refuge — IUCN Category V (Protected Landscape/Seascape) …   Wikipedia

  • Crocodile Dundee in Los Angeles — Theatrical release poster Directed by Simon Wincer …   Wikipedia

  • Crocodile (2000 film) — Crocodile Directed by Tobe Hooper Produced by Ryan Carroll Frank Strausser Ronnie Truss Mark Wooding Starring Mark McLachlan Caitlin Martin Summer Knight Chris Solari …   Wikipedia

  • Crocodile (Homonymie) — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”