It's a long-standing problem on the Wimbledon branch with all of the train indicators between Wimbledon Park and Parsons Green displaying whatever they want!
I came through a few nights ago on a C stock and they were all indicating: 1. Not Stopping - Stand Clear 2. Not Stopping - Stand Clear!
I think they did try to improve their reliability a few years back, but when trains are running in the wrong order for whatever reasons, then it confuses the indicators and they just display what they think is right. I think Parsons Green is the first place they can be corrected by Earl's Court.
This sounds like the old problem of the train indicators being out of step. It used to occur at the east end of the District quite a lot. It's caused by some sort of lock-up in the individual stations describer cupboard whereby when a train puts the starting signal to danger the indicator does not 'step' to the next description. So the last one shown remains on the board. I.E. If the last train was an Upminster that description will remain on show even if the next train is going elsewhere. The AET's used to come along and step it manually in the cupboard or by bridgeing the running rails after the starting signal blockjoint with a bit of wire. This would put the track down and would restore the balance.
the signalman can put right the t/d's at putney bridge but seldom do, there is a reson why it shows the wrong descriptions but all i know its something to do with the WARS computer it was explained once why it don't work correctly but since then i have slept ;D ;D ;D i believe the dot matrix sign on the e/b at west brompton has been turned off due to it not showing the correct information not due to a local fault.
before i forget this the WARS computer has the current timetable programme into it and will only put up the t/d's what it thinks it should be the network rail signaller has no input to change the description so justs leaves it to the signalman at earl's court to sort out
q8 you was saying when a aet shorted the running rails out to over come the problem with a extra t/d but at most locations at the east end (past whitechapel) the t/d's get transmitted via a trainstop contact except in controlled signalled sites.
Well I don't know what contacts the circuit goes through aet but I do remember the tech coming along and simply bridging the running rails. The trainstop would raise and the description would be wiped off the board. I don't think that is adviable south of Putney Bridge though, given the running rail return.