So here’s another guide on signalling, this time for crossovers (ie where two or more lines are joined together with switches/points). The terminology I’m using here relates to British signalling but standard practices are used throughout the world but using different words to describe the same thing. However, in these guides, British trains travel on the left so I have transposed the operation of signalling to the right hand side to correspond to the native direction of trains in Train Fever.

First, consider the diagram below:

Figure A – If you’re the arrow travelling in the direction the arrow is showing on the line it’s positioned on, the junction ahead is considered to be trailing, in that the direction of travel is trailing away from you

Figure B – Again, if you’re the arrow travelling in the appropriate direction, the junction ahead is considered to be leading, in that the direction of travel is leading away.

Consider the diagram below of a simple crossover from a mainline to a bi-directional (travelling in both directions) branch line.



You can click the above image for a larger, clearer view of the signal placements.

Figure A – If the green train wishes to cross from the main line to the branch line, it needs to cross over the red line. However, doing so would then represent a danger to on-coming traffic (red trains). Therefore the signals are positioned in such a way to protect the flow of traffic on all three lines. Note that it’s only important to protect trailing junctions – this means that any traffic joining the line from the trailing junction gets right of way. Additionally, traffic on each respective line is given way to by traffic crossing its path but on a first come, first served basis (in reality it would depend upon the priority of specific trains ie freight trains would yield to passenger trains, passenger trains would yield to express trains and so on). Note that for this to work effectively, the bi-directional branch line should only have one signal protecting the entire line, however the main line also needs to be protected from traffic approaching it from the branch.

Figure B – In the UK, and indeed throughout the world, it’s customary for the signals to switch to red as soon as the front of the train passes into it’s protecting block. In this case, the green train has passed the signal which forces the red train to stop before the branch line’s trailing junction. The green train is now safe to proceed along the dotted line toward its destination. Once the green train enters the branch line block, the signal turns to red and hence protects the entire branch line and no other trains can enter the branch until the train has cleared. In normal working, no other trains would ever be sent to the line so it could never block the any of the main lines – this is an important consideration and you need to be sure you only ever use one train on the line, except where you use passing loops along the branch (see my guide on passing loops here http://www.train-fever.com/forums/topic/increasing-line-capacity).

Figure C – In the case where a train is blocking the path of the green train, it is normal for the green train to halt before the trailing main line junction and await a clear path. It’s important that you take into consideration the number of blocks you have available following a cross over so that junctions always remains clear and passable. Should the red train on the far right need to turn around, it can safely traverse the junction and proceed along the green main line without causing an obstruction.

Figure D – In this case a train has approached the main line and is waiting to join the main line and travel along the red line to its destination, however both the main line train and the branch line train met at the signals at the same time. In this case, the main line traffic should always get priority unless it is of a lower priority in terms of train class (whether it’s a freight train, passenger train or express). Note that the green line remains unaffected by any movements of the red trains.

A fairly detailed look at signalling for crossovers and I know it seems a little daunting but if you just remember a simple rule “to always protect trailers”, then you can’t go wrong with signalling.

Hope this helps but should anyone have any questions, comments or suggestions, please feel free to comment.