Sifa is a type of
deadman's control system used on German-influenced European railways.
[{{cite web , url = http://www.virtualmarket.innotrans.de/index.php5?id=1022238&highlight=&fid=523&offset=0&Action=showProduct , title = Deadman's control system UDB , accessdate=2008-12-24] Although
deadman's pedals are commonly used on railways worldwide, Sifa systems are specifically those codified by
German Industrial Norms VDE 0119-207-5.
In
Switzerland
Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...
the equivalent system is called 'safety control' (''Sicherheitssteuerung'').
[Eidgenössisches Departement für Umwelt, Verkehr, Energie und Kommunikation]
''Ausführungsbestimmungen zur Eisenbahnverordnung (AB-EBV)''
as at: 1 July 2016
Description
Sifa is short for ''Sicherheitsfahrschaltung'', German for "safety driving circuit". It is usually a pedal and/or large press button, which monitors the alertness of the driver. The driver has to repeatedly press a button after a fixed interval; if they fail to do so, the train will carry out an emergency stop. It complements the external train safety systems:
PZB,
LZB
Linienzugbeeinflussung (or LZB) is a cab signalling and train protection system used on selected Deutsche Bundesbahn, German and Austrian Federal Railways, Austrian railway lines as well as on the AVE and some commuter rail lines in Rail transpo ...
and
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 ...
.
[Ernst Anderegg: ''Sicherheitssteuerungen für Triebfahrzeuge''.]
Schweizerische Bauzeitung, Vol. 68 (1950), Issue 15
(E-Periodica, pdf3.0 MB)
In
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
the ''Zeit-Zeit-Sifa'' (time-time Sifa) is common. In this system, the engine driver holds a pedal or button down for 30 seconds and must then briefly release the pressure. Thus the system can confirm that the driver is still able to react. If the driver does not react after 30 seconds, the system warns the driver, at first optically, then for a few seconds acoustically. After a further short period of time without any reaction the train is automatically stopped. The ''Zeit-Weg-Sifa'' (time-distance Sifa) system takes account of the distance travelled, as well as time, since the last activation.
In electric trains such as those working on
U- and
S-Bahn
The S-Bahn ( , ), , is a hybrid urban rail, urban–suburban rail system serving a metropolitan region predominantly in German language, German-speaking countries. Some of the larger S-Bahn systems provide service similar to rapid transit syst ...
lines the Sifa has for a long time been combined with the
driving switch
Driving is the controlled operation and movement of a land vehicle, including cars, motorcycles, trucks, and buses. A driver's permission to drive on public highway
A highway is any public or private road or other public way on land. It in ...
. This is where the concept of the dead man's switch first arose. If the button was released (due to the driver becoming incapacitated) the train was automatically stopped.
Drivers must carry out a Sifa test before using a train, to check that the automatic braking is functioning correctly.
Following some serious accidents in which drivers fell asleep but somehow the pedal was still being activated, the
Deutsche Reichsbahn
The ''Deutsche Reichsbahn'' (), also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the Weimar Republic, German national Rail transport, railway system created after th ...
in
East Germany
East Germany, officially known as the German Democratic Republic (GDR), was a country in Central Europe from Foundation of East Germany, its formation on 7 October 1949 until German reunification, its reunification with West Germany (FRG) on ...
introduced a special type of Sifa (''Sifa86''). Here the driver has to acknowledge, by pressing a button, an optical signal given at random times and distances.
See also
*
Automatic train protection
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 ...
(ATP)
*
Dead man's switch
A dead man's switch is a switch that is designed to be activated or deactivated if the human operator becomes incapacitated, such as through death, loss of consciousness, or being bodily removed from control. Originally applied to switches on a ...
*
Dead-man's vigilance device
A dead man's switch is a switch that is designed to be activated or deactivated if the human operator becomes incapacitated, such as through death, loss of consciousness, or being bodily removed from control. Originally applied to switches on 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 ...
*
Watchdog timer
A watchdog timer (WDT, or simply a ''watchdog''), sometimes called a ''computer operating properly timer'' (''COP timer''), is an electronic or software timer that is used to detect and recover from computer malfunctions. Watchdog timers are wide ...
*
Emergency brake
*
Hand brake
In road vehicles, the parking brake, also known as a handbrake or emergency brake (e-brake), is a mechanism used to keep the vehicle securely motionless when parked. Parking brakes often consist of a pulling mechanism attached to a cable which ...
References
External links
Why it's safe to take the train
Occupational safety and health
Railway safety
Safety switches