"Mr Thant" wrote in message
...
An hour or two ago the Crossrail Bill became the Crossrail Act, which
means as soon as the funding agreement is signed (due in September)
the thing might actually see the light of day.

Hm,

On this basis we would have had a Channel tunnel built by 1978 [1]

It means nothing.

tim

[1], OK I guessed I can't remember the actual date

On 23 Jul, 17:19, 1506 wrote:
On Jul 23, 5:02*am, Jamie *Thompson wrote:



On 23 Jul, 12:28, wrote:

On Jul 22, 8:23 pm, Mr Thant
wrote:

An hour or two ago the Crossrail Bill became the Crossrail Act, which
means as soon as the funding agreement is signed (due in September)

Given the governments record level of borrowing and deficit its
building I wouldn't get too excited just yet. Just because its
approved doesn't mean it'll happen.

B2003

Quite. The history of the railways (and indeed, London Transport
itself) is littered with Acts that never got built. *Sigh* The Watford
& Edgware is my personal poster child for that scenario.

This is not the same thing. *The Watford and Edgware debacle is a
result of WWII followed by the implementation of London's greenbelt.

The W&ER was authorised in 1903. WW2 started, as I'm sure you are
aware, in 1939, with the green belt following around 1946-1950. 36
years of procrastination and insufficient attempts to raise funding
puts even Crossrail to shame, WW2 only halted the first stage to
Bushey Heath that London Transport was interested in building. They
had a notion of later going on to Bushey village if funding came about
after the war (see the redesign of Bushey Heath Station in 1943-44),
but AFAIK they never had the will (or means) to go as far as the full
route to Watford.

Crossrail is needed and it was needed yesterday.

I'd wager yesterday would be to late, TBH.

A closer parallel might be Chelsey to Hackney, now there IS a tale of
procrastination!

You may have me there. I believe that the various proto-plans for the
Chelsea-Hackney line were proposed as sibling schemes of those that
became the Victoria and Jubilee Lines, which would put it somewhere
around the 1930s, I think. What will they come up with once they've
sorted that out?

On Jul 23, 1:28*pm, Jamie Thompson wrote:
On 23 Jul, 17:19, 1506 wrote:



On Jul 23, 5:02*am, Jamie *Thompson wrote:

On 23 Jul, 12:28, wrote:

On Jul 22, 8:23 pm, Mr Thant
wrote:

An hour or two ago the Crossrail Bill became the Crossrail Act, which
means as soon as the funding agreement is signed (due in September)

Given the governments record level of borrowing and deficit its
building I wouldn't get too excited just yet. Just because its
approved doesn't mean it'll happen.

B2003

Quite. The history of the railways (and indeed, London Transport
itself) is littered with Acts that never got built. *Sigh* The Watford
& Edgware is my personal poster child for that scenario.

This is not the same thing. *The Watford and Edgware debacle is a
result of WWII followed by the implementation of London's greenbelt.

The W&ER was authorised in 1903.

Thanks I didn't know that. Your knowledge of history is remarkable.

WW2 started, as I'm sure you are
aware, in 1939, with the green belt following around 1946-1950. 36
years of procrastination and insufficient attempts to raise funding
puts even Crossrail to shame, WW2 only halted the first stage to
Bushey Heath that London Transport was interested in building. They
had a notion of later going on to Bushey village if funding came about
after the war (see the redesign of Bushey Heath Station in 1943-44),
but AFAIK they never had the will (or means) to go as far as the full
route to Watford.

Pitiful eh!

Crossrail is needed and it was needed yesterday.

I'd wager yesterday would be to late, TBH.

:-)

A closer parallel might be Chelsey to Hackney, now there IS a tale of
procrastination!

You may have me there. I believe that the various proto-plans for the
Chelsea-Hackney line were proposed as sibling schemes of those that
became the Victoria and Jubilee Lines, which would put it somewhere
around the 1930s, I think. What will they come up with once they've
sorted that out? -

The one good thing to come out of this is that, if Chelsea-Hackney is
ever built, it is likely to be mainline loading gauge. An earlier
incarnation would have been tube gauge.

Charles Ellson wrote:
On Wed, 23 Jul 2008 11:13:12 -0700 (PDT), Mr Thant
wrote:

On 23 Jul, 18:27, Tom Anderson wrote:
As i mentioned then, there are cross-section diagrams of the CTRL
which also show station humps, although i imagine this is less
about saving energy and more about getting an otherwise very deep
tunnel into shallow cut-and-cover stations.

Crossrail vertical alignment diagram, showing tunnels dodged:
http://www.crossrail.co.uk/80256B090053AF4C/Files/centralareaverticalalignment/$FILE/vertical+alignment.jpg

There's an alternate version on the last page of this PDF, showing
geology:
http://billdocuments.crossrail.co.uk...ethodology.pdf


Hmmm. I hope they've remembered all the other "pipework" that is down
there.

I hope they've remembered that half of the Connaught Tunnel is flooded! How
flooded is it, anyway - ankle deep ?

Mr Thant wrote:
On 23 Jul, 18:19, Tom Anderson wrote:
Why does it stick up so much? Why does it need to go any further than
ground level (or, say, three metres above ground level)?

It includes pedestrian entrances, and it also incorporates the
ventilation outlets/emergency stairs at either end.

Does it contain mirrors or lenses to gather sunlight and direct it downward?
Or even a movable white sheet?

On Wed, 23 Jul 2008, Mr Thant wrote:

On 23 Jul, 18:27, Tom Anderson wrote:
As i mentioned then, there are cross-section diagrams of the CTRL which
also show station humps, although i imagine this is less about saving
energy and more about getting an otherwise very deep tunnel into shallow
cut-and-cover stations.

Crossrail vertical alignment diagram, showing tunnels dodged:
http://www.crossrail.co.uk/80256B090053AF4C/Files/centralareaverticalalignment/$FILE/vertical+alignment.jpg

There's an alternate version on the last page of this PDF, showing
geology:
http://billdocuments.crossrail.co.uk...ethodology.pdf

Oh, brilliant! The details on how the tunnels will be dug are fascinating.
IOW, boring is interesting.

London, it seems, sits on five layers of different materials. At the
bottom is chalk; on top of that, Thanet Sands, and then Lambeth Group
(which i read is a mixture of clays and sands of various kinds, with
pebble beds at the bottom in some places), on top of which is the famous
London Clay, and then a dusting of river terrace and superficial deposits
right at the surface (or, as laymen call it, 'earth').

Everything west of the junction between the eastern branches at Stepney
Green is going to be bored through London Clay, with a minor excursion
into the Lambeth Group beneath the Fleet valley. Most of the way, the
tunnel is near or at the base of the Clay - it's only west of Bond Street
that it's any distance above it, as that's where the Clay becomes much
deeper. Between Stepney Green Junction and Pudding Mill Lane, things are
much the same. Between the junction and the Victoria Dock portal, though,
the tunnel is deeper, and largely bored right through the Lambeth Group,
mostly at its base, where it rests on the Thanet Sands. For the hop across
the river, where the London basin ends and these layers fade away, the
tunnel is right through chalk.

Anyway, the upshot of all that is that, with the possible exception of the
far eastern end of the core tunnel, there isn't a geological constraint on
depth. It's clearly possible to tunnel through the Lambeth Group, as that
happens in the east, so i see no reason why that wouldn't be possible in
the west. I assume the real constraint is therefore the presence of
specific awkward things underground, which are not shown on those maps.

I note from another diagram that the core tunnel will be dug in three big
drives, and one little one. One comes from Royal Oak in to Farringdon, one
from the Limmo Peninsula in Docklands into Farringdon, one from the
Pudding Mill Lane portal to the Stepney Green junction, and then there's a
little one from Limmo to the Victoria Dock portal - don't know why. Now,
clearly, the branched tunnel has to be done with two drives, one starting
at either eastern portal, only one of which will continue to Farringdon.
But i find the choice of which that is interesting in comparison to the
geology: the central stretch is mostly through London Clay, as is the
Pudding Mill Lane stretch, whereas the Victoria Dock stretch is mostly
through Lambeth Group. I would naively have thought that you'd want to
customise your TBM for the kind of material you're digging through, and in
that case, it would make more sense for the Pudding Mill Lane drive to be
the one that carries on to Farringdon, so that you could have a
Clay-specific machine on that one, and a Group-specific machine on the
Victoria Dock drive. Evidently, though, i know nothing about this.

tom

--
Optical illusions are terrorism of the mind.

"John Rowland" wrote in message
...
Charles Ellson wrote:
On Wed, 23 Jul 2008 11:13:12 -0700 (PDT), Mr Thant
wrote:

On 23 Jul, 18:27, Tom Anderson wrote:
As i mentioned then, there are cross-section diagrams of the CTRL
which also show station humps, although i imagine this is less
about saving energy and more about getting an otherwise very deep
tunnel into shallow cut-and-cover stations.

Crossrail vertical alignment diagram, showing tunnels dodged:
http://www.crossrail.co.uk/80256B090053AF4C/Files/centralareaverticalalignment/$FILE/vertical+alignment.jpg

There's an alternate version on the last page of this PDF, showing
geology:
http://billdocuments.crossrail.co.uk...ethodology.pdf


Hmmm. I hope they've remembered all the other "pipework" that is down
there.

I hope they've remembered that half of the Connaught Tunnel is flooded!
How flooded is it, anyway - ankle deep ?


They did a walk-through a few weeks ago- we were on holiday, otherwise I
could give an eye-witness account from my wife.
Brian

On Jul 23, 9:28 pm, Jamie Thompson wrote:
Bushey Heath that London Transport was interested in building. They
had a notion of later going on to Bushey village if funding came about
after the war (see the redesign of Bushey Heath Station in 1943-44),
but AFAIK they never had the will (or means) to go as far as the full
route to Watford.

Probably a good thing in hindsight. Now its still fairly green around
that area. If the tube had gone out that way it would have been
another few miles of urban sprawl. Though who knows, in a parallel
universe maybe its been built ... )

Anyway , the northern line has enough trouble coping with its length
as it is. Can you imagine the service if it had another 5 miles on
track bolted on north of edgware and perhaps the line from mill hill
east to edgware too?

B2003

On 24 Jul, 12:37, wrote:
Probably a good thing in hindsight. Now its still fairly green around
that area. If the tube had gone out that way it would have been
another few miles of urban sprawl. Though who knows, in a parallel
universe maybe its been built ... )

I'm in a mixed mind about that. I agree, it is still lovely and green
around here, but so is Elstree & Borehamwood, with a mainline
connection no less. The main utility of the extension would not be
through commuting, but local domestic journeys (e.g. I have family
around Colindale, Burnt Oak, Hendon, etc. that I don't see as much as
I probably should unless I drive as the bus journey from Bushey takes
too long). There was a quote by Frank Pick who claimed that they'd
like a nice rural (different?) stretch of line as it wouldn't increase
pressure on the central section. Really, they only really wanted the
line for the depot; the stations were pretty much an afterthought. On
a vaguely related note, when the Northern line gets upgraded they're
going to find themselves back in the 1930s again...namely they'll need
room for a lot more trains with no obvious contenders for stabling on
their existing route. They may well come to regret selling of the
Aldenham Bus facility (redeveloped from the Bomber Factory, itself
developed from the unused, abet completed, Bushey Heath Depot) in the
1990s yet. They may have to revert to the unfavoured alternatives such
as Mill Hill (aka. Copthall Sports Grounds) or Edgwarebury Park (aka.
Brockley Hill Station's site), so they'd both be quite good green
spaces fights), or expanding Highgate Depot by cutting down lots of
the trees in Highgate Wood (again, that'll be a nice political bit of
environmental fighting).

Anyway , the northern line has enough trouble coping with its length
as it is. Can you imagine the service if it had another 5 miles on
track bolted on north of edgware and perhaps the line from mill hill
east to edgware too?

Ironically, I think the extension wouldn't have increased loadings as
much as you'd think though, the Bushey services were to run via Mill
Hill & the Finchley branch, so I'd imagine most sane commuters would
have changed at Mill Hill Broadway/The Hale for the Midland Suburban
(Thameslink) services (so you might have even got Finchley commuters
heading contraflow if the Thameslink service was good enough). As is,
they generally drive to Elstree and Borehamwood or Watford anyway
(though I go via H&W).

On Jul 24, 1:21 pm, Jamie Thompson wrote:
connection no less. The main utility of the extension would not be
through commuting, but local domestic journeys (e.g. I have family

Maybe in 1940 , not now. It would be prime commuter belt country. Or
not-so-much country rather. As soon as the piccadilly line was
extended to Cockfosters in the 30s the houses followed it. I can't see
any reason why Bushey would have been different.

1990s yet. They may have to revert to the unfavoured alternatives such
as Mill Hill (aka. Copthall Sports Grounds) or Edgwarebury Park (aka.

Extended beyond Mill Hill East would be a no brainer. They'd only have
to knock down 2 houses and level the trackbed which surprisingly (to
me) is all in situ as far as Page Street. In fact just beyond MHE
station they could probably squeeze in 3 or 4 sidings before the
bridge.

B2003
Brockley Hill Station's site), so they'd both be quite good green
spaces fights), or expanding Highgate Depot by cutting down lots of
the trees in Highgate Wood (again, that'll be a nice political bit of
environmental fighting).

Anyway , the northern line has enough trouble coping with its length
as it is. Can you imagine the service if it had another 5 miles on
track bolted on north of edgware and perhaps the line from mill hill
east to edgware too?

Ironically, I think the extension wouldn't have increased loadings as
much as you'd think though, the Bushey services were to run via Mill
Hill & the Finchley branch, so I'd imagine most sane commuters would
have changed at Mill Hill Broadway/The Hale for the Midland Suburban
(Thameslink) services (so you might have even got Finchley commuters
heading contraflow if the Thameslink service was good enough). As is,
they generally drive to Elstree and Borehamwood or Watford anyway
(though I go via H&W).