A catch point is aspecial type of point that will de-rail any train that passes over it, unless a route has been set over it. They are also used to derail trains rolling backwards down a hill, to prevent them crossing a junction and potentially hitting another train. There are 3 main types of catch point:
Motorised catch points have their blades (the rails that move on a point) motorised, so trains can legitimately pass over them in either direction. These are typically found at the exits of yards or platforms to derail runaways.
Sprung catch points have their blades moved by the weight of a train's wheen on the blade, which closes it. Obviously, trains can only pass over in one direction. This type is normally used to derail trains rolling backwards down a hill.
Wide-to-guage catch points derail a train by 'dropping' it into the middle of the track. They are always motorised, and are used where confined space means that derailing the train to either side of the track would be likely to cause a crash.
See this page to see how they are represented in SimSig.
Last edited by GeoffM on 15/09/2016 at 03:00