
Crossrail: The monster tunnelling under London streets - tommoor
http://www.bbc.com/future/story/20150602-crossrail-the-monster-tunnelling-under-london-streets
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kitd
The BBC did a fascinating series of programmes on Crossrail over the winter.

At one point, the new tunnel was being cut past an existing underground
station (I forget which one). It had to be threaded in 3D between a few access
tunnels carrying passengers on their way up or down, and at one stage came
within 5-6 feet of them, all without them knowing.

Edit: for those who can access it
[http://www.bbc.co.uk/programmes/b04b7h1w](http://www.bbc.co.uk/programmes/b04b7h1w)

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jsingleton
It was Tottenham Court Road station when they were boring under Soho Square.
It had to go below the escalators but above the Northern Line.

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kitd
That's the one. Thanks!

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Eric_WVGG
Reading about this sucked me into an hour of reading about Seattle’s “Bertha”
debacle. If you want to hear about a parallel universe account of a project
like this going straight to hell…

disaster predicted: [http://www.thestranger.com/seattle/what-could-possibly-
go-wr...](http://www.thestranger.com/seattle/what-could-possibly-go-
wrong/Content?oid=4399657)

disaster realized:
[http://slog.thestranger.com/slog/archives/2014/12/16/guest-e...](http://slog.thestranger.com/slog/archives/2014/12/16/guest-
editorial-seattle-pull-the-plug-on-the-tunnel-unless-you-can-answer-these-
seven-questions)

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curtis
I think claiming that the "disaster" has been "realized" is premature. They're
repairing the tunnel boring machine now. If they are able to restart the
machine and complete the tunnel, then is it a disaster? Heck, even if they end
up completing the tunnel several years late and a billion dollars over-budget,
it still wouldn't be a disaster.

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Eric_WVGG
I hope you're right, but they've experienced all these problems and setbacks
and got only 10% of the tunnel dug. The remaining 90% of the dig had better be
nearly problem free or maybe even hollow...

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andyjohnson0
Interesting article. I was surprised by how mature and automated the
technology was, given how relatively few tunnelling operations of this scale
have been attempted.

Also, the concrete slabs, and presumably therefore the tunnel, have a
projected lifespan of 120 years [1]. I wonder what use the tunnels will be put
to in 2120?

[1] [http://www.railtechnologymagazine.com/Rail-News/Concrete-
seg...](http://www.railtechnologymagazine.com/Rail-News/Concrete-segments-
produced-for-Crossrail)

~~~
pjc50
_relatively few tunnelling operations of this scale have been attempted_

More than you think, I suspect; TBMs are a fairly mature technology. Crossrail
is not as impressive as the Channel Tunnel, which is a major feat of alignment
as it was tunneled from both directions to meet in the middle.

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andyjohnson0
_" More than you think, I suspect"_

That is very likely.

Wikipedia has a list of long tunnels [1]. And "Tunnel Talk" lists what the
world's "mega TBMs" are up to [2] (frustratingly they quote tunnel diameters
but not lengths). Seems like these machines are kept very busy, which makes
sense given their cost.

Edit: Even more tunnel-related stuff at
[http://tunnelbuilder.com/](http://tunnelbuilder.com/)

[1]
[http://en.wikipedia.org/wiki/List_of_longest_tunnels_in_the_...](http://en.wikipedia.org/wiki/List_of_longest_tunnels_in_the_world)

[2] [http://www.tunneltalk.com/Discussion-Forum-Mega-
TBMs.php](http://www.tunneltalk.com/Discussion-Forum-Mega-TBMs.php)

~~~
omh
_Seems like these machines are kept very busy_

I believe that many of them are actually single-use. Some (or perhaps all?) of
the Crossrail TBMs are being buried at the end of their tunnel. Apparently the
effort of removing them isn't worth their resale value?

That tunnel talk page does mention that several TBMs are being reused though
so perhaps this is changing with newer/larger machines.

~~~
nly
At least one of the Chunnel TBMs was also driven in to its own grave.

~~~
Someone
If you do not take them out (which would have meant dismantling them and
dragging the parts through kilometers of tunnel), they have to be, or they
would block the tunnel they dug.

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dvdcxn
While it is pretty cool, Crossrail and HS2 piss me off to no end as despite
being an project that only affects england, the entire UK foots the bill.
Wales, Northern Ireland and Scottish taxpayers foot the bill, under the
pretense that this affects the entire UK, that it is a project that benefits
the whole country.

And that's half right, most cities untouched by these projects have been
predicted to lose out economically, as the south east beast grows ever more
engrossing.

[http://www.bbc.co.uk/news/uk-24589652](http://www.bbc.co.uk/news/uk-24589652)

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growse
So you're saying infrastructure projects which definitively cannot benefit
everywhere equally should never be funded by central taxation?

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jamescun
They are probably referring more to infrastructure projects being
disproportionately focused on the south east, rather than only executing
infrastructure project with macro economic effects.

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growse
Crossrail, I can understand - it overtly benefits London alone.

However, given that one of HS2's main objectives is to free up freight
capacity on the WCML which benefits most places from London up through to the
North West and beyond, I'm struggling to see parent post's perspective.

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matthewmacleod
I'm fascinated by the idea of exploring the underground layout of cities
interactively in 3D. Is there anything that offers that experience? I expect
geographic data might be available for tube lines, for example.

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Brakenshire
There are 3D tube maps:

[http://brunoimbrizi.com/experiments/#/07](http://brunoimbrizi.com/experiments/#/07)

[https://vimeo.com/67869313](https://vimeo.com/67869313) (last one seems to be
only available as a video)

Also, just as a tangential point, you may be interested in the BBC documentary
from last week about underground spaces in Rome, which was excellent. It's
called "Rome's Invisible City", and there are a couple of copies on youtube:

[https://www.youtube.com/watch?v=6QAaYi0Zt4I](https://www.youtube.com/watch?v=6QAaYi0Zt4I)

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mauricemir
Interesting I was walking near mansion house (in the City) yesterday and could
feel something rumbling underneath my feet through the pavement which I assume
was Crossrail.

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justincormack
More likely the underground I would think.

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jblok
Most likely that was the circle/district line. It's only one flight of stairs
down from Cannon Street and Mansion House. Not sure how many metres, but it
isn't far down at all.

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cxz
Someone managed to run between them actually, leaving the train at Mansion
House and catching up to it again at Cannon Street!
[https://www.youtube.com/watch?v=PH_Z8Ghuq6E](https://www.youtube.com/watch?v=PH_Z8Ghuq6E)

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Graham24
you wait to crossrail 2 if that ever happens, the same sort of thing, but from
the SW to the NE.

