Train speed optimization
Encyclopedia
Train speed optimization, also known as Zuglaufoptimierung, is a system that reduces the need for train
s to brake and accelerate, resulting in smoother and more efficient operation.
While train speed optimization needs some technical infrastructure, it is more of an operational concept than a technical installation. One can relatively easily implement train speed optimization using for instance cab signalling
(e.g. using ETCS), but the presence of a cab signalling system does not necessarily mean that it uses train speed optimization. Train speed optimization may also be implemented using conventional signalling
.
of next occupied block. This is inefficient in many cases, because this way the train comes to a halt in front of the red signal and has to accelerate again from zero.
may replace these installations). Further, the track must be equipped with inductive loops that detect the presence of trains with sufficient precision (or other means of detecting the positions of the trains). Finally a computer system is needed that is able to reasonably predict the movements of the trains for the next few minutes.
Swiss Federal Railways:
Train
A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...
s to brake and accelerate, resulting in smoother and more efficient operation.
While train speed optimization needs some technical infrastructure, it is more of an operational concept than a technical installation. One can relatively easily implement train speed optimization using for instance cab signalling
Cab signalling
Cab signalling is a railway safety system that communicates track status information to the cab, crew compartment or driver's compartment of a locomotive, railcar or multiple unit, where the train driver or engine driver can see the information....
(e.g. using ETCS), but the presence of a cab signalling system does not necessarily mean that it uses train speed optimization. Train speed optimization may also be implemented using conventional signalling
Railway signalling
Railway signalling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Being guided by fixed rails, trains are uniquely susceptible to collision; furthermore, trains cannot stop quickly, and frequently operate at speeds that do not enable them to stop...
.
Conventional signal operation
Usually, trains are allowed to run at the maximum speed the track allows until the distant signalRailway signal
A signal is a mechanical or electrical device erected beside a railway line to pass information relating to the state of the line ahead to train/engine drivers. The driver interprets the signal's indication and acts accordingly...
of next occupied block. This is inefficient in many cases, because this way the train comes to a halt in front of the red signal and has to accelerate again from zero.
Advantages using train speed optimization
If the train slows down much earlier, it reaches, given the right timing, the distant signal just when the home signal switches to green. This way, the train does not need to stop. Thus, wear on the brakes is reduced and the train uses less energy. But the main reason, especially for trains that accelerate slowly, is that the train passes the home signal at high speed, compared to the conventional case where the train often has to accelerate from standstill. This effectively increases track capacity, because the time it takes for the train to run from the distant signal (that has just turned green) to the home signal is often much less than the time it takes for a train to accelerate from the home signal.Equipment
For a train speed optimization system to work, it is necessary to have a signalling system which is capable of displaying several different speeds, for instance 40, 60, 90 km/h and the full line speed, which also requires an train protection system that is able to handle these cases (cab signallingCab signalling
Cab signalling is a railway safety system that communicates track status information to the cab, crew compartment or driver's compartment of a locomotive, railcar or multiple unit, where the train driver or engine driver can see the information....
may replace these installations). Further, the track must be equipped with inductive loops that detect the presence of trains with sufficient precision (or other means of detecting the positions of the trains). Finally a computer system is needed that is able to reasonably predict the movements of the trains for the next few minutes.
Train speed optimization in practice
The expensive and complicated installations usually only make sense for heavily used routes.Swiss Federal Railways:
- LenzburgLenzburgLenzburg is a town in the central region of the Swiss canton Aargau and is the capital of the district of the same name. The town, founded in the Middle Ages, lies in the Seetal valley, about 3 kilometres south of the Aare river. Lenzburg and the neighbouring municipalities of Niederlenz and...
-KillwangenKillwangenKillwangen is a municipality in the district of Baden in the canton of Aargau in Switzerland.-History:The town was first known as Chullewangen as early as 1227. The name is alemannish in origin. For nearly 600 years, Killwangen was dependent on the monastery in nearby Wettingen. In 1798, Napoleon's...
(since 2000) - ZurichZürichZurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...
-AltstettenAltstettenAltstetten may refer to:*Altstetten, Erdweg, Bavaria, Germany*Altstetten, Rennertshofen, Bavaria, Germany*Altstetten , Canton of Zürich, SwitzerlandSee also Altstätten.... - Around OltenOltenOlten is a town in the canton of Solothurn in Switzerland and capital of the district of the same name.Olten's railway station is within 30 minutes of Zurich, Bern, Basel, and Lucerne by train, and is a rail hub of Switzerland.-History:...
(installed 2004, current status unknown) - Probably other places (Zürich S-BahnZürich S-BahnThe Zurich S-Bahn system is a network of rapid transit rail lines that has been incrementally expanded to cover the ZVV area, which comprises the entire canton of Zurich and portions of neighboring cantons The Zurich S-Bahn system is a network of rapid transit rail lines that has been...
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