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Post by principlesdesigner on Apr 5, 2018 4:26:30 GMT
Is it between White city & East Acton ? +1
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Guards
Apr 5, 2018 3:09:25 GMT
Post by principlesdesigner on Apr 5, 2018 3:09:25 GMT
Experienced guards closed there door well before the headwall as any distraction could be fatal. Also it deterred passengers trying to get in as the train was moving off though some did. The head story is true. This is quite good. Even in open sections they did not keep the door open very long. Just an observation in this video; the guard more often sat in a passenger seat between stations. Guards were supposed to monitor the platform until one third out of the platform, to ensure safe departure. the red handle above the guards panel is an emergency brake handle which was pulled down to stop the train, hence the expression "pulling him down"
Interestingly the guard acts incorrectly at the five minute point, you see him push the button to close the guards door as the train moves off then continue to watch the platform, presumably keeping the door open with his shoulder or foot.. He should not do this for safety reasons. Should he happen to fall off the train the door would close and might trap his foot dragging him along the platform, if button not pushed then he would just fall clear. I remember seeing many a guard do this on the Northern - I thought it was standard practice!
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Post by principlesdesigner on Apr 3, 2018 3:50:07 GMT
The District line originally used AC track circuits, and in some areas still does, the frequency of these tracks was 33 1/3Hz. The signal relays, trainstop valves, points valves & detection etc. are also AC.
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Post by principlesdesigner on Mar 29, 2018 5:46:35 GMT
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Post by principlesdesigner on Mar 15, 2018 8:18:55 GMT
Exterior shot of Kenton from Kenton Lane? +1
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Post by principlesdesigner on Mar 8, 2018 0:18:15 GMT
There were a few - WER and some of the sites in the east which had early M63 replacements Sorry, I know these acronyms are generally station codes and I can usually figure them out, but I can't get WER! Sorry WEst Ruislip
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Post by principlesdesigner on Mar 7, 2018 7:41:24 GMT
Don’t remember the central having clamplocks at all There were a few - WER and some of the sites in the east which had early M63 replacements
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Post by principlesdesigner on Mar 7, 2018 5:55:58 GMT
I thought that BEG had an EH power-pack but I could well be wrong One end at Bethnal Green was converted to Surelocks (electric) a few years ago. There's never been an EH unit there. I must have been dreaming then! I was sure that the EH was tried in "the hole" somewhere. I do recall the Surelock conversion vaguely
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Post by principlesdesigner on Mar 6, 2018 7:37:53 GMT
Not all outside points were M63’s where you had 4ft EP points the air motor was replaced with one that worked with hydraulics. This was not done down the tunnel areas as hydraulic oil is flammable and poses a greater risk. I thought that BEG had an EH power-pack but I could well be wrong
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Post by principlesdesigner on Feb 16, 2018 2:51:27 GMT
Although to be pedantic the "lever" exists only in the brain of the WESTRACE interlocking computer at GRH. I did say lever (or equivalent), would have been a bit harder to explain in terms of the .RU being set HI, point .NL HI, .RL LO and stopping the RLR from picking up etc... Sorry - I missed the (or equivalent)!
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Post by principlesdesigner on Feb 16, 2018 2:47:05 GMT
Thanks tut & DWS, my memory is a bit hazy, Central line re-sig was a long time ago
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Post by principlesdesigner on Feb 15, 2018 0:34:55 GMT
Would the purpose be to prevent a set of points from moving if a train was over them? Surely that couldn't happen anyway, e.g. even under ordinary circumstances ATO in the rain might cause a train to stop over a set of points due to the unreliability of ATO in poor rail adhesion conditions, and the train is just restarted? (I am asking from the perspective of a complete amateur but curious passenger...) If you mean once you've had a SPAD and are over a set of points, well in theory yes, but the points would need to be immediately beyond the signal such that the rear of the train is still on the approach track circuits. In any case, you're quite right that the points shouldn't move under a train as they would be locked by the presence of the train, but we generally don't like to rely on just one level of locking for a train movement. RS requires the signal lever (or equivalent) to be reversed as if the signal was clearing normally, thus it applies mechanical locking to the point lever to that the point lever cannot be moved. (The point lever is also electrically locked by the train occupying the track circuits over the points.) Once the signal lever is reversed it is then locked electrically just as it would be for a normal signalled move, therefore maintaining the locking on the point lever. In some cases, the requirements for unlocking the signal lever are actually more complicated than they would be for a colour light move! Although to be pedantic the "lever" exists only in the brain of the WESTRACE interlocking computer at GRH. The N (& V) style frames are and were a thing of beauty! I can't remember whether the original interlocking at GRH was a slave frame operated from HAI, a la Harrow or whether there was just 1 frame covering all of HAI & GRH, IIRC the cabin was adjacent to the HAI entrance to the depot.
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Post by principlesdesigner on Feb 8, 2018 1:49:39 GMT
Met line at Croxley Green?
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Post by principlesdesigner on Oct 18, 2017 8:40:54 GMT
You are correct with braking rate!
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Post by principlesdesigner on Oct 17, 2017 11:01:12 GMT
IIRC the reason for LOB EB repeater being "timed" was that it was visible too early and would impede headway when at caution, so was set to "pop-up" when at caution. This was later modified so that it always "popped-up" as the drivers got used to creeping if they couldn't see it! The problem with signal sighting in the past is that the sighting point is calculated, and if this is not then proved to be valid for all circumstances, the problems which drainrat reports can arise.
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Post by principlesdesigner on Aug 4, 2017 14:14:48 GMT
Everything else which has nothing to do with track circuits 33 1/3hz was considered to interfere with the S stock traction system, before the S stock was cleared to run everywhere track circuits were changed to either 125hz but they soon ran out of relays. Completely changed to either Westinghouse FS2550 or Bombardier Ebi200 otherwise known as Ti21. Other way round - S Stock traction package generates frequencies in the 33 1/3 Hz range, so could falsely energise the track relay
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Post by principlesdesigner on Aug 1, 2017 9:11:25 GMT
Thanks all
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Post by principlesdesigner on Aug 1, 2017 7:36:45 GMT
Morning everyone. Quick question : do ballast trains and the like have a loco at each end?
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