Swedish railway signalling

Swedish railway signalling system
The signalling system used on the standard gauge railway network in Sweden is based on that of the traditional mechanical semaphore signals. Currently only colour light signals are used, together with the Ansaldo L10000 Automatic Train Control system.

Some road crossing signals have a distant signal (Vägkorsningsförsignal (V försignal)), placed at a distance (usually not braking distance) from the road crossing signal. Signal Meaning Expect Stop before crossing(Crossing not clear) The road crossing is not secured. The train must stop before the crossing if possible. Expect Pass(Crossing clear) The road crossing is secured. The distant road crossing signal is nicknamed "skull" (döskalle).

Because the aspects are in reverse with more green lights meaning slower the aspects are not fail safe, so lamp proving is needed to prevent lamp failure giving a faster aspect. Single and Double Green signals work the other way with Norwegian railway signalling and and it would be unsafe for drivers to cross the border, unless ATP were fitted. It is not permitted for Swedish drivers to drive into Norway and opposite where there is no ATC, unless extra education is taken (and before ATC was introduced everywhere in the other country except for a few kilometers from the border where crew change stations were located). This meant that freight trains Oslo–Narvik passed Hallsberg southeast of Oslo until the shortcut Kil–Ställdalen was upgraded to ATC in 2017.

European Rail Traffic Management System(ERTMS/ETCS) has been introduced on a few railways in Sweden such as Botniabanan where it is actively being used. Mainly ERTMS level 2 is used, in which basically no light signals exist and all messages are shown on a display in the driver's compartment of the train. Two railways, Citybanan and Citytunneln use signalling according to ERTMS level 1, although ATC is still used there, not ERTMS (for now).

An unauthorized stop signal passage (OSPA), ie the passage without permission of a signal or sign meaning stop (red main signal, vertical dwarf signal, ERTMS arrow sign and more) is considered a serious incident. They are divided into three categories, A where the signal showed stop even before the process, which may be due to the driver, failure of the train brakes, slipping and more, category B, where the signal was inadvertently set to stop due to technical error or mistake of the signalman, and category C, where the signal was intentionally stopped, for example due to a sudden danger such as a car at a level crossing. If it is suspected to be due to the driver, he may not drive any more until the investigation has been completed, and another driver may drive the train after an investigator has collected information about the train's route, usually causing a multiple hour delay. A driver who has caused several OSPAs permanently loses the license.