Discussion:
Bakerloo line tunnel
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b***@cylonHQ.com
2018-03-12 10:00:09 UTC
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I took my first ride on the bakerloo line for years this morning and I noticed
that southbound from charing X to waterloo the tunnel lining suddenly changes
into rather old looking concrete for a fair distance. Is this due to WW2
bombing or something else? The iron rings resume just before waterloo.
Peter Able
2018-03-12 19:27:22 UTC
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Post by b***@cylonHQ.com
I took my first ride on the bakerloo line for years this morning and I noticed
that southbound from charing X to waterloo the tunnel lining suddenly changes
into rather old looking concrete for a fair distance. Is this due to WW2
bombing or something else? The iron rings resume just before waterloo.
I believe that the sections of the Bakerloo Thames tunnels in gravel were
lined in the 1920s with a steel liner, the gap inbetween the liner and the
original cast iron segments being filled with concrete. Later on (1940s),
when the track base was being rebuilt (in concrete) the steel liner was
removed. The 1920s work was meant to stiffen and improve waterproofing in
the tunnel. I guess that it was thought that the enhanced concrete on its
own could do the job.

Further work was carried out in the 1990s, though that was mostly to prevent
undermining of the tunnel (?)

The WW2 under-Thames casualty was the direct hit on an unused bit of the
Northern line.

PA
Richard J.
2018-03-12 21:40:18 UTC
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Post by Peter Able
Post by b***@cylonHQ.com
I took my first ride on the bakerloo line for years this morning and I noticed
that southbound from charing X to waterloo the tunnel lining suddenly changes
into rather old looking concrete for a fair distance. Is this due to WW2
bombing or something else? The iron rings resume just before waterloo.
I believe that the sections of the Bakerloo Thames tunnels in gravel were
lined in the 1920s with a steel liner, the gap inbetween the liner and the
original cast iron segments being filled with concrete. Later on (1940s),
when the track base was being rebuilt (in concrete) the steel liner was
removed. The 1920s work was meant to stiffen and improve waterproofing in
the tunnel. I guess that it was thought that the enhanced concrete on its
own could do the job.
Further work was carried out in the 1990s, though that was mostly to prevent
undermining of the tunnel (?)
The WW2 under-Thames casualty was the direct hit on an unused bit of the
Northern line.
There was also an incident in 2012 when a Bakerloo train "hit a tunnel", which I think meant that some extremity on the train hit a piece of quick-dried cement grout that had been applied in overnight maintenance, but had oozed out before it had dried.
See https://www.telegraph.co.uk/news/uknews/road-and-rail-transport/9228164/Bakerloo-line-suspended-after-tube-hits-tunnel-no-casualties.html
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)
b***@cylonHQ.com
2018-03-13 09:25:25 UTC
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On Mon, 12 Mar 2018 21:40:18 +0000
Post by Richard J.
Post by Peter Able
The WW2 under-Thames casualty was the direct hit on an unused bit of the
Northern line.
There was also an incident in 2012 when a Bakerloo train "hit a tunnel", which
I think meant that some extremity on the train hit a piece of quick-dried
cement grout that had been applied in overnight maintenance, but had oozed out
before it had dried.
See
https://www.telegraph.co.uk/news/uknews/road-and-rail-transport/9228164/Bakerlo
-line-suspended-after-tube-hits-tunnel-no-casualties.html
FTA:
"Geoff Martin, an RMT spokesman, said: "There has been a build-up of rain water
behind the tunnel wall and on the ceiling of the tunnel as well. "

Rain from when, the ice age?? Another RMT rocket scientist keeping us informed.
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