Tom
Administrator
Signalfel?
Posts: 4,198 
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Post by Tom on Jan 3, 2011 12:39:39 GMT
Why they're kept, I don't know, but as long as they're in situ they must be detected. If they close and they're not detected it could be a bit embarassing!
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Post by londonse on Jan 3, 2011 16:19:21 GMT
Why they're kept, I don't know, but as long as they're in situ they must be detected. If they close and they're not detected it could be a bit embarassing! I understand that but if the floodgates are still there and the signalling as such caters for that fact why not just remove them or is there another reason, North End stated that the Central line still have the floodgates but there is no interlocking in the signalling for them or are they still in circuit? Paul |
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Deleted
Deleted Member
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Post by Deleted on Jan 3, 2011 23:18:40 GMT
They're left as de-commissioned / manually operated and still interlocked with the signalling because it's difficult / expensive to do the work to remove / permanently secure them - plus the associated signalling modifications.
As part of the NL TBTC commissioning the electrically driven gates which slide across the track will be secured and will not be detected by the new TBTC system. The hydraulic driven gates which are in the roof of the tunnel and drop down to close off the tunnel will still be detected by the TBTC in case there is a mechanical failure, but there is no system in place any more to drive them.
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North End
Beneath Newington Causeway
Posts: 1,769
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Post by North End on Jan 3, 2011 23:55:39 GMT
Why they're kept, I don't know, but as long as they're in situ they must be detected. If they close and they're not detected it could be a bit embarassing! I understand that but if the floodgates are still there and the signalling as such caters for that fact why not just remove them or is there another reason, North End stated that the Central line still have the floodgates but there is no interlocking in the signalling for them or are they still in circuit? Paul Particularly the 1950s floodgates, I think removing them would be a big task. With the gates being larger than the tunnels, I presume they would have to be cut up on site, the 1950s gates are pretty hefty, so I guess it's getting into the territory of not worth the hassle. The Thames Barrier may reduce the risk of Thames flooding, but I don't think it caters for one of the original purposes of the gates, namely the under-river tunnels becoming breached. During WW2, I believe only one under-river tunnel was hit in this way - the disused Embankment Loop of the Northern Line, which had already been plugged with a brick wall, and the under-river section remains plugged to this day. I wonder if it is still flooded? The below-land section of the Loop still exists, complete with some impressive stalagtites, though can only be accessed from trackside so isn't easily visitable. |
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Post by jmm on Jan 5, 2011 15:47:31 GMT
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