Signal Question

[fairysdad]

The attached file is a location near me (the approach to Poole station). I walk over the road bridge on a pretty much daily basis, and 99% of the time the signal shown is red.

My question is why this signal is red all the time. I've narrowed it down to a few options:

1. All railway signals are red unless a train is approaching
2. The signal is linked to the points and is red until the signaller says the points are correct
3. The signal is linked to the level crossing gates, so will show red unless the barriers are down
4. Whenever I walk across the bridge, there happens to be a train in section
5. Some other reason entirely

I am quite curious to know what this signal signals exactly.

(Not shown on diagram is another road bridge between the level crossing and the station platforms.)

 

[ainsworth74]

It's protecting the level crossing and will be red unless the barriers are down and the section is clear for a train to enter it.

 

[Old Timer]

From the diagram you have provided, the signal is a main running signal and it controls two routes into the station.

The first route is the straight ahead route, and the second route, which is indicated by the fitting atttached to the signal head at an angle on the right hand side, is towards the platform via the crossover points.

The signal will always remain at Red until the level crossing barriers have been lowered and the route is set. The signal should clear to at least a single yellow.

When a train is routed to the platform via the crossover, the signal will only clear when the train is closely approaching it. The indicator will also light up witha row of 5 white lights to indicate to the Driver that he will take this route.

I am sure one of the Drivers who work that line will be able to add to this.

 

[fairysdad]

Thanks for that

So it's kind of 2 and 3 then. I knew about the signal route display, which is why I wasn't sure if it was that bit that the signal was signalling or the crossing. I've only once seen the route aspect lit once, with the green signal showing as well - previously I didn't think that the signal could be 'protecting' the points.

 

[142094]

Depends where the station is, but the signal might also be there for a sequential turnback, so the train arrives from the left, and goes into the plaform on the bottom side to reverse.

 

[driver9000]

1. All railway signals are red unless a train is approaching
2. The signal is linked to the points and is red until the signaller says the points are correct
3. The signal is linked to the level crossing gates, so will show red unless the barriers are down
4. Whenever I walk across the bridge, there happens to be a train in section
5. Some other reason entirely

1. The normal position for a controlled signal is Danger unless it has been pulled off for an approaching train. Given the location on your diagram and there are multiple routes available from it, this signal will be controlled.

2. Yes, signals are interlocked to pointwork on running lines. The points have a detection system to ensure they are 'fitting' (ie moved fully across). If the points are not detected by the system then it isn't possible to pull the signal off.

3. Yes.

4. Again, possible. Also possible is that no train has been signalled when you see it.