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Post by dave1 on Nov 7, 2015 14:49:47 GMT
Can anyone tell me what the audible alarms were in the sidings? They all had them Walthamstow/Kings Cross/Victoria/Brixton. I don't think other lines are the same but might be wrong.
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Post by Nortube on Nov 8, 2015 9:57:17 GMT
I don't know about the Vic line, but many sidings (and other places) had overrun detection by means of a Track Circuit Interrupter. In some places, this sounded an alarm locally (platform or office). I assume that most tunnel sidings were alarmed because, unlike open sidings, it would not be easy to see if a train had hit the buffers or gone into the sand drag. I'm not sure when this was introduced. At the link below, there is a booklet that contains brief information about the operation of TCIs and other things - scroll down the page at the link [ Click here ]
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Post by Nortube on Nov 8, 2015 10:38:01 GMT
Looking it up, the siding alarms you mention are different to an alarm that might be given by an overrun detector (Brixton didn't have TCIs).
It appears that the audible warning is triggered by the train as it approaches the 2 car countdown marker in the siding. I assume that the warning is an audible warning that sounds in the siding (and thus heard by the T/Op in the cab) as a warning to the T/Op that the train is approaching a dead end.
I don't know if these alarms were installed at the opening of the Vic line or were a later addition. They didn't have them on the Northern line sidings.
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Post by Nortube on Nov 8, 2015 11:01:16 GMT
There was protection of trains entering sidings work and warnings carried out on the combine in the early / mid seventies. Some of this, such as the yellow lights entering the siding came about following the Motorman entering Tooting Broadway siding at speed and being killed in the crash. Other, such as policemen in the siding, probably came about after the Moorgate crash
It seems strange that the same audible alarm on the Vic line wasn't used elsewhere, although with a policeman in operation and thus forcing the driver to be below 10mph, the driver would be aware that they are approaching a dead end and at that speed, the fixed trainstop before the buffer / sand drag would normally stop the train before any collision.
As I type this, I've just realised that the Vic line doesn't have trainstops and thus there are no policemen in the sidings. Driving an auto train in manual mode in a siding would limit the speed to around 10mph. ATO / ATP would have no need of a policeman because no code would give an emergency stop in the same way as the train getting tripped. Therefore, the audible warning must just be the equivalent of a "wake up you're almost there"!
Even though not necessary and probably not workable, a similar warning would no doubt have saved many a "kissed buffer" or playing in the sand in depots and sidings where a driver has got distracted for whatever reason at the last minute.
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Post by dave1 on Nov 9, 2015 12:33:04 GMT
Thanks for the reply's, I thought that the alarms were for intruders or something. At first I thought why not in other sidings on other lines but being a different system and no track side equipment to stop the train. I wonder if there is something like it on the other lines which have automatic working.
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Post by hellocontrol on Nov 9, 2015 14:53:57 GMT
Thanks for the reply's, I thought that the alarms were for intruders or something. At first I thought why not in other sidings on other lines but being a different system and no track side equipment to stop the train. I wonder if there is something like it on the other lines which have automatic working. They are not for intruders they are for telling the T/Op that the end of the tunnel is approaching. I don't know if other lines have anything like it.
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Post by hellocontrol on Nov 9, 2015 14:58:51 GMT
There was protection of trains entering sidings work and warnings carried out on the combine in the early / mid seventies. Some of this, such as the yellow lights entering the siding came about following the Motorman entering Tooting Broadway siding at speed and being killed in the crash. Other, such as policemen in the siding, probably came about after the Moorgate crash It seems strange that the same audible alarm on the Vic line wasn't used elsewhere, although with a policeman in operation and thus forcing the driver to be below 10mph, the driver would be aware that they are approaching a dead end and at that speed, the fixed trainstop before the buffer / sand drag would normally stop the train before any collision. As I type this, I've just realised that the Vic line doesn't have trainstops and thus there are no policemen in the sidings. Driving an auto train in manual mode in a siding would limit the speed to around 10mph. ATO / ATP would have no need of a policeman because no code would give an emergency stop in the same way as the train getting tripped. Therefore, the audible warning must just be the equivalent of a "wake up you're almost there"! Even though not necessary and probably not workable, a similar warning would no doubt have saved many a "kissed buffer" or playing in the sand in depots and sidings where a driver has got distracted for whatever reason at the last minute. When the Vic line first opened movement into/out of the sidings was done in slow manual, but it was realised that should an emergency happen the train would not be able to be stopped by anyone other than the T/Op. The procedure was changed and movement was then done in coded manual, somewhere in the back of my mind something was done to do with the codes which acted like a speed control trainstop but for the love of money I can not remember what it was.
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Post by dave1 on Nov 10, 2015 12:13:21 GMT
Thanks even more I wonder what the other lines do.
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Post by Nortube on Nov 11, 2015 0:53:57 GMT
I posted earlier that a train being driven in manual mode would limit the speed to around 10mph. However, whilst this is true for the 95 stock (around 8mph), I don't think that the Vic line had this restriction, and so would be able to motor up to 25mph. Just doing a quick google, I found what you might be looking for on Tubeprune's site: [ Click here ]See under Slow Manual. I'd forgot about the vigilance button. That would allow a train to move right to the end of the siding as long as the speed was slow in the same way as conventional policemen physically limited the speed. Similarly, SCAT introduced an enforced (approx.) 10mph speed restriction for three minutes by retro-fitted equipment on conventional stock and, later on, this evolved into the enforced 8mph on 96 and 95 stock when the Master Control Switch was put into the Forward position - used when in depot or sidings, after being tripped, and various other reasons.
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