Grouped Exit Signals

In Switzerland (possibly also in other countries?) it is usual for smaller stations to have only one exit signal in each direction. Because the station tracks are bidirectional, the signal refers to multiple tracks. This means that the exit signal is normally beyond the points where the tracks converge.

Simplest case

It is easy to model this situation in Rail3D - all you have to do is place a Hidden Signal on each track (S1, S2), and the real exit signal (S3) beyond the station. The exit signal (S3) should have Lock Through set, to avoid the possibility that the signalling system sets a route ending at S3.

 
    S1(h)
-----------
           \     Lock through
    S2(h)   \    S3
--------------------------------

Variants

In this simple set-up, if there are two trains waiting to depart in the same direction, the signal doesn’t tell them which of them is allowed to depart when the signal clears.

There are a number of ways to avoid this ambiguity when using a common exit signal. The most common is for the signal to display a different proceed aspect for each track. In the example above the signal might display Fahrbegriff 1 (clear) for the straight track (route from S2) and Fahrbegriff 2 (40km/h) for the curved track. A sign next to the track tells drivers the number of the signal aspect they can treat as a signal applying to their track.

This is not completely trivial to model in Rail3D — you would have to script S1 and S2 to modify the aspect shown by S3.

MRG 11/06/2013 16:32:12