The longest signal failure

[Deleted]

Does anyone know of any time when the signalling has failed and remained broken for a very long time?

ISTR reading something solidbond once posted about a failure at Bayswater inner rail where the signal was red for eight days...

[Deleted]

i have had a 29 hour shut down on the east london line


recently there has been a massive problem with OP2 (i think OP is the cabin code for edgware road) which has been failing intermittently for about 9 months now

[Harsig]

aetearlscourt said:

i have had a 29 hour shut down on the east london line


recently there has been a massive problem with OP2 (i think OP is the cabin code for edgware road) which has been failing intermittently for about 9 months now

I can name a signal in the Marlborough Road area that has been failing intermittently for two years at least and one in the Finchley Road area that has carried a defect for at least five years. Both faults relate to the approach control function on the signal and only result in delaying clearance of the signal. The latter failure did however once cause the signal to remain at danger when a second separate failure occurred in the same area where as it would have cleared if it had been working correctly; trains had to trip past four signals instead of two because of this long standing failure. Allegedly the problem with fixing this fault is that the signal and track side equipment are the responsibility of Metronet while the relays controlling the signal are the responsibility of TubeLines.

In general all the really long failures will be intermittent in nature because this makes them very hard to pin down.

[Deleted]

There is a defective with the "time departure stored" on the programme machine at Watford. It sticks up on platform one, again its intermittent, but has been on and off for ages.

There was an indication problem for the track circuit at Chorelywood Sb platform, where by the cabin board at Ricky was showing as though there was a train there. That went on for a good year, until one day a TO was fixing something else and as if by magic it sorted itself!!

[Deleted]

MIE318 was out for around 3 weeks some years ago.... Apparently one of the inter car barriers was loose and smashed the signal to smithereens...

[Deleted]

harsig said:

I can name a signal in the Marlborough Road area that has been failing intermittently for two years at least and one in the Finchley Road area that has carried a defect for at least five years. Both faults relate to the approach control function on the signal and only result in delaying clearance of the signal. The latter failure did however once cause the signal to remain at danger when a second separate failure occurred in the same area where as it would have cleared if it had been working correctly; trains had to trip past four signals instead of two because of this long standing failure. Allegedly the problem with fixing this fault is that the signal and track side equipment are the responsibility of Metronet while the relays controlling the signal are the responsibility of TubeLines.

How in the h*ll did that sort of lashup happen? Who in their right mind would assign part of the setup to one infraco and another part to another one?!?

Also, why would trains have to trip past four signals instead of two? "Marlborough Road" area could be anywhere between the outer homes for Swiss Cottage or the autos near Lords...

harsig said:

In general all the really long failures will be intermittent in nature because this makes them very hard to pin down.

Indeed, but I was more curious as to whether or not anything like solidbond's experiences at Bayswater had ever re-occurred.

[Tom]

aetearlscourt said:

recently there has been a massive problem with OP2 (i think OP is the cabin code for edgware road) which has been failing intermittently for about 9 months now

'Tis true. You can't move in the lower Relay room for all the monitoring equipment. I had to investigate a wire count anomlaly in there on Tuesday and there was only just enough room to swing a cat.

harsig said:

I can name a signal in the Marlborough Road area that has been failing intermittently for two years at least and one in the Finchley Road area that has carried a defect for at least five years. Both faults relate to the approach control function on the signal and only result in delaying clearance of the signal.

A879 per chance?

tubeoperator92 said:

MIE318 was out for around 3 weeks some years ago.... Apparently one of the inter car barriers was loose and smashed the signal to smithereens...

Errr... no. Inter car barriers can take lenses out quite easily but signal heads are a little bit more robust.

Besides, there is no MIE318, and even if such an incident did occur it wouldn't be left in that state for any longer than to that night's engineering hours.

[Deleted]

programme machines do not cause signal failures as the signal operator is supposed to supervise them and interveen when necessary just for my two pennys worth in then

if there is approach controlled signals which require a inductor speed check then 45% of them do not work due to lack of spares so they rely on the second shot system to work but if that also failures then the signal will remain at danger

only trouble i have known at bayswater is in the mornings a circuit called the GYR (Signal Special Relay) drops because of the tracks not dropping in the right sequence this is the same circuit they have on single line working i.e olympia so to get round it they just run a train up and tripping the past the signals then after that it works correctly

[Tom]

aetearlscourt said:

only trouble i have known at bayswater is in the mornings a circuit called the GYR (Signal Special Relay)

It's a Signal Disengaging Relay Pat , a signal special relay would be a GZR.

The original 'failure' at Bayswater was the trackbed flooding which gave concern over shunting performance of the track circuits. This was the reason for the GYR circuits being fitted, and the signal at danger was maintained in that state quite deliberately.

[Chris M]

theonekea said:

How in the h*ll did that sort of lashup happen? Who in their right mind would assign part of the setup to one infraco and another part to another one?!?

I could be really cynical here and just replace the word "setup" with the word "Underground"

[Deleted]

What about all those signal failures down the Wimbo branch... is that caused by equipment failure itself, or is it to do with the drainage and consequent flooding... Has that problem been eliminated yet?

[Deleted]

the problem down wimbledon well southfields really has been sorted at last about a year ago now when network rail sorted out there drainage problem