On Jun 17, 7:05*pm, "Paul Scott"
wrote:
"Tom Anderson" wrote in message

rth.li...

On Wed, 16 Jun 2010, Andy wrote:
The central London tunnels will be built to an increased loading gauge..
The planned running tunnel diameter of 6.2m is nearly as large as the
6.3m RER tunnels in Paris and certainly big enough for most continental
stock.

Any idea what that corresponds to in either W6/8/12 etc terms or UIC
A/B/C? And whether other constraints for those gauges (or kinematic
envelopes or whatever we're supposed to call them now), like radius, will
be met?

Another relevant point, is that Crossrail has continuous walkways in the
tunnels, so the running line is not centred in the bore. That presumably
means all the theoretical height gained is not actually usable?


Having a side walkway doesn't preclude having the track in the centre
of the tunnel. Remember that the walkway won't be at track level, but
at the height of the train floor/doorway, so there will be the
'triangluar' space between track level, floor level and the tunnel
wall to fit the walkway (with a similar space on the other side of
course). The larger the tunnel, the bigger this space will be.

But as I said in an earlier post, the trains have to fit the existing
tunnelled parts of the route, especially the single track Connaught tunnels
under the docks beyond Custom House...


I was under the impression that these tunnels are being enlarged. I
can't find the information on the Crossrail website, but there is
information from other sites, from announcement of the bidding last
week (e.g. http://www.cnplus.co.uk/news/contrac...01056.article).
This mentions that the tunnels will have the linings removed, filled
with concrete and then excavated again to give a larger gauge, but
doesn't mention what the size will be.