|The Sv system (Signalverbindung, Signal Combination) was
created in 1928 as the first German colour light signalling system for the urban railways
of Berlin and Hamburg, where it is still used, although it
is in the process of being replaced by Ks signals. As with the Hl system
and the Ks system, main and distant signal aspects are displayed in
a single head.
The main signal aspect is shown on the left half of the signal head, while the right half indicates the aspect the signal in advance will show.
Note that some signals are searchlight type, i.e. instead of a number of differently coloured lamps, rotating colour blends are used to change colours from amber to green; so a signal head may be equipped with just two or three lights, or the red light may be at the low centre. Also the shape of the signal head may vary, sometimes the lower corners are cut off angular.
If the next signal is closer than the usual distance, a white vertical arrow (Bremspfeil, "brake arrow") is displayed. On newer signal heads the white arrow may instead be represented as a dot-matrix bar.
|Pictures:||Hamburg Sv surface and tunnel signals|
|Berlin Sv and subway signals|
These are the aspects an Sv signal may display:
|Sv 1: clear, expect clear||Sv 2: clear, expect stop||Sv 3: clear, expect slow||Sv 4: slow, expect clear||Sv 5: slow, expect slow|
|Sv 6: slow, expect stop||Sv 0: stop, then proceed on sight||Hp 0: (absolute) stop
See also post plates
|Sv 2, next signal is closer than braking distance||Sv 1, signal positioned to left of track|
Some signals are capable of showing Hp 0 (stop) as their most restrictive indication, while others may just be able to indicate Sv 0 (proceed on sight).
The rule for passing a signal showing stop or a failed signal is determined by the signal's post plate.
|home||home & distant signals|
|Sk signals||LZB Cab signalling|