Braking distance
The braking distance is a term used in railway operations and describes the distance at which the distant signal and main signal on a railway line are usually apart. This distance corresponds to the braking distance of a train, which is reached when a so-called service braking is carried out (the rapid braking distance is shorter).
If a train driver receives a term at a distant signal that indicates a reduction in speed or the stop at the associated main signal, he must immediately initiate braking in order to either brake the train down to the prescribed speed within a specified distance or to bring this main signal to a standstill before the stop bring.
Braking distances in Germany
The laws and ordinances valid in Germany for rail operations such as the General Railway Act , the Railway Construction and Operating Regulations and the Railway Signal Regulations as well as guidelines from infrastructure companies such as B. Ril 408 - driving service regulation of DB Netz AG and Ril 301 - signal book of Deutsche Bahn AG know different speeds and distances for this distance. These usually differ between 1000 meters for main lines and 400 meters for secondary lines with a corresponding reduction in the maximum permissible speed for the latter. In the case of unfavorable route conditions, such as steep gradients or restricted signal visibility due to curves, buildings, vegetation, etc., the distant signal distance can be greater than the standard distance. The length of the deviating distance is noted separately in the preliminary remarks on the book timetable .
In Germany, with a braking distance of 1000 m, the distant signal may generally be at a distance of 950 to 1500 m in front of the main signal, with a braking distance of 700 m between 665 and 1050 m and with a braking distance of 400 m between 380 m and 600 m. If the smallest distance is not reached, the distant signal is more than 5% shorter than the braking distance. Individual light pre-signals, pre-signals on the mast of a main signal and Ks main signals with pre-signal function then have an additional white light that informs the driver of the shortfall in the distance. Form pre-signals have a white triangle with a black border on the pre-signal board. If the monitoring signal of a level crossing is at a braking distance of more than 5% shorter than the distance in front of the level crossing, this is marked with a white triangle with a black border on the diamond board (Bü 2) and on the monitoring signal.
In the case of trains with a speed higher than 160 km / h, the train driver is no longer informed of braking orders or braking distances by signals on the route, but rather via the liner train control display in the driver's cab.
In the area of BOStrab , valid for example for all German underground trains , trams and light rail vehicles away from the railway tracks, special system-specific braking distances apply.