In message ,
lid writes
Brainwashed, if the infrastructure greatly assists in economic growth
then the next generation can easily pay for it.
That's one big "if"
--
hugh

In message ,
lid writes

"hugh" ] wrote in message
...

Brown never did that at all. Stop reading the Daily Mail.

I was wondering when the Daily Mail would resurface.

You must stop reading the Daily Mail, Express, Torygraph, etc.
What would you recommend? - the drivel you quote from New Statesman.
--
hugh

In message ,
lid writes

"hugh" ] wrote in message
...

Gordon Brown saved the world? Don't make me laugh.

He put together the world rescue plan.
Hahahahaha - you HAVE made me laugh.
--
hugh

In message ,
lid writes

"hugh" ] wrote in message
...
In message , "Dave Plowman (News)"
writes
In article ,
Tim Watts wrote:
Brown failed to regulate the banks and Blair dissappeared up his own
arse with his desire to become an "international statesman" (ie get
involved in everyone's wars).

And where is the emergency legislation brought in immediately by the
Tories to regulate the banks? Pigs might sooner fly...

Responsibility for that particular item lies with - err - Vince Cable

Brainwashed, no Cameron!!!!!
No, Cable.
--
hugh

In message ,
lid writes

"hugh" ] wrote in message
...

Brown left the country in a better position than others and this fool
Cameron takes credit. But he has made millions unemployed in only 18
months.

Most of them doing total non-jobs in the public sector

Brainwashed again....."Brown left the country in a better position than
others and this fool Cameron takes credit. But he has made millions
unemployed in only 18 months."

Your knowedge of basic economics is ZERO!

Still ahead of you then.
--
hugh

In message
,
harry writes
On Dec 31 2011, 9:09*am, Steve Firth wrote:
"Dave Plowman (News)" wrote:

In article ,
* *hugh ] wrote:
But how many of those eligible to vote were at that meeting?

Never actually counted them but in those days the meetings were
generally held in the open air just off site during lunch breaks so I
guess the turn out would be pretty high.

If, as is claimed, there was massive successful intimidation, surely those
wimps who couldn't stand up for themselves would simply stay away from the
meeting?

Those who did stand up for themselves in King Arthur's. Coal War continue
to suffer abuse and ostracism to this day. Calling those who didn't want to
see their families suffering because the bread winner was "a scab" wimps
shows a massive lack of understanding on your part or a massive dose of
cynicism if you were actually aware of how dissenters within the unions are
treated.

Bricks through your window on a daily basis tend to cause even strong
independent individuals to toe the line.

That is true. I have seen it myself. In the S Wales coalfields it is
carried down the generations, even though the mines are long closed.
The scabs and non scabs have to live in separate places. And their
children and grandchildren.

These Welsh know how to hold a grudge.

Ironic as the Welsh were the original "blacklegs"
--
hugh

In message ,
lid writes

"harry" wrote in message
...

In the S Wales coalfields it is
carried down the generations, even
though the mines are long closed.
The scabs and non scabs have to
live in separate places. And their
children and grandchildren.

When scabbing you have to consider the consequences. A SCAB is a SCAB!

The following was written by Jack London in 1915.

Another piece of my advice you have followed - quoting your source
rather than claiming it as your own.
I'll have you reading the Daily mail yet - but then you already do,
otherwise how would you know about what's in it?
--
hugh

In message ,
lid writes

"Tim Watts" wrote in message
...
harry wrote:

On Dec 31 2011, 9:09 am, Steve Firth wrote:
"Dave Plowman (News)" wrote:

In article ,
hugh ] wrote:
But how many of those eligible to vote were at that meeting?

Never actually counted them but in those days the meetings were
generally held in the open air just off site during lunch breaks so I
guess the turn out would be pretty high.

If, as is claimed, there was massive successful intimidation, surely
those wimps who couldn't stand up for themselves would simply
stay away
from the meeting?

Those who did stand up for themselves in King Arthur's. Coal War
continue
to suffer abuse and ostracism to this day. Calling those who didn't want
to see their families suffering because the bread winner was "a scab"
wimps shows a massive lack of understanding on your part or a massive
dose of cynicism if you were actually aware of how dissenters within the
unions are treated.

Bricks through your window on a daily basis tend to cause even strong
independent individuals to toe the line.

That is true. I have seen it myself. In the S Wales coalfields it is
carried down the generations, even though the mines are long closed.
The scabs and non scabs have to live in separate places. And their
children and grandchildren.

These Welsh know how to hold a grudge.

I doubt it applies to the Welsh in general, but I'm happy to label
those it
does apply to as a socio-retard.

A scab is a SCAB.
And by the same token, Drivel is drivel.
--
hugh

Onetap wrote:
On Jan 1, 11:35 am, The Natural Philosopher
wrote:

probaly because your newreader is broken..looks ok from here

No newsreader, I'm using Google Groups.

well there you are.

On Jan 1, 1:16*pm, The Natural Philosopher
wrote:

well there you are.

Here I am indeedy; it hasn't happened before so I didn't know what
was going on..
I must assume Google Groups has a glitch.

On Jan 1, 1:52*pm, Onetap wrote:
On Jan 1, 1:16*pm, The Natural Philosopher
wrote:

well there you are.

*Here I am indeedy; it hasn't happened before so I didn't know what
was going on..
*I must assume Google Groups has a glitch.

Based on all previous slags of Google Groups we are now in for another
round of such. Having pursued some of the other options for reading
usenet, I have found that GG does in fact produce the best
presentation - and I cannot believe that the other suppliers do not
have their glitches either.

Rob

On Jan 1, 11:31*am, Onetap wrote:
Why are all the green public transport posts showing up as new topics?

*It doesn't happen with other topics, so what's going on with this
one?

We have gone over 1000 replies. Google groups doesn't seem to like it.

"Terry Casey" wrote in message
...
In article om,
says...

"Terry Casey" wrote in message
...
In article , lid
says...

dennis@home wrote:


Extra mass doesn't help when going up and down hills unless you
think
doing 1 mph on the level and rolling down a hill up to 70(or
whatever
the speed limit is) and then slowing down to 1 mph as you go up the
other side is actually useful. Driving at the speed limit means
there
is
nowhere to store any extra kinetic energy without speeding up which
is
probably both illegal and dangerous.

Some tube train lines use this principle by having tubes that go down
between stations.

But its an expensive way to save electricity.

A bit of oversimplification there! Which would mean that long tube
lines
would end up with a vast disparity in tunnel depth at the ends!

In practice, the method used is to build the stations on 'hills' in the
tunnel network with a sharp incline on the approach to assist fast
stopping and a longer, shallower gradient beyond the station to aid
rapid acceleration on departure.

I don't see how this is any more expensive than boring tunnels without
the gradients ...

I can, unless the trains only run one way.
You would need two tunnels to do it in both directions.

But you still need two tubes (tubular tunnels) if there were no
gradients!

Its cheaper to bore one tunnel these days.


Perhaps you should refresh your knowledge of the (London) tube system?

I don't really care about the London tube system.

On Jan 1, 5:56*pm, harry wrote:


We have gone over 1000 replies. *Google groups doesn't seem to like it.

Aha! Coconut for Harry.

1001 posts in the first Green Public Transport thread shown on Google
groups; thereafter many 'new threads' on the same subject, most with
only 1 or 2 posts.

"Doctor Drivel" wrote in message
...


Brainwashed I gave the figures, tax NEVER went up with Nu Labour. Read it
again and you can move your lips when reading it.

We already know that is a lie.
They increased the NI tax to start with.

Virtually everyone was paying more tax under labore and they still had to
sink us into debt to satisfy their egos.
Now we are having to pay even more tax as a direct result of the idiots like
you that voted labore.

"hugh" ] wrote in message
...


What would you recommend? - the drivel you quote from New Statesman.

I thought he was getting it from the Beano.

On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:



Its cheaper to bore one tunnel these days.


How much would it cost to bore, says, one mile of dual tunnel capable of
carrying two tracks, and how much for one tunnel large enough for both
tracks? Make any assumption you like about the specification of the trains
- e.g. Circle line standard.

--
Rod

"John Williamson" wrote in message
...
dennis@home wrote:


"Terry Casey" wrote in message
...
In article , lid says...

dennis@home wrote:


Extra mass doesn't help when going up and down hills unless you think
doing 1 mph on the level and rolling down a hill up to 70(or whatever
the speed limit is) and then slowing down to 1 mph as you go up the
other side is actually useful. Driving at the speed limit means
there is
nowhere to store any extra kinetic energy without speeding up which
is
probably both illegal and dangerous.

Some tube train lines use this principle by having tubes that go down
between stations.

But its an expensive way to save electricity.

A bit of oversimplification there! Which would mean that long tube lines
would end up with a vast disparity in tunnel depth at the ends!

In practice, the method used is to build the stations on 'hills' in the
tunnel network with a sharp incline on the approach to assist fast
stopping and a longer, shallower gradient beyond the station to aid
rapid acceleration on departure.

I don't see how this is any more expensive than boring tunnels without
the gradients ...

I can, unless the trains only run one way.
You would need two tunnels to do it in both directions.

You've obviously never used the Underground then. That's *exactly* how it
works.

And that has what to do with what I said?

"Tony Bryer" wrote in message
...
On Sat, 31 Dec 2011 15:33:14 -0000 Dennis@home wrote :
You do understand that the pension holidays were required by the revenue.
The funds were deemed to be overfunded and the revenue required action to
stop them being overfunded.

So? Shareholders and management got an unexpected bonus in good times but
weren't prepared to meet their moral obligation to employees when things
changed.

Or just weren't able to.
It can take a lot to recover five years worth of input when the government
steals a few billion and the economy goes down.
The authorities should have allowed the companies to carry on paying in the
good times even if the funds were overfunded.

"Doctor Drivel" wrote in message
...

I don't see how this is any more expensive than boring tunnels without
the gradients ...

I can, unless the trains only run one way.
You would need two tunnels to do it in both directions.

That is what they do. Two tunnels is also for safety reasons.

Which is more expensive, making me correct.

Tim Streater wrote:
In article , Doctor Drivel wrote:

A scab is a SCAB.

So tell us, drivel, what should happen to a scab (or be done to them)?


pick them and eat them.

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:



Its cheaper to bore one tunnel these days.


How much would it cost to bore, says, one mile of dual tunnel capable of
carrying two tracks, and how much for one tunnel large enough for both
tracks? Make any assumption you like about the specification of the
trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

In article ,
says...

On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:



Its cheaper to bore one tunnel these days.


How much would it cost to bore, says, one mile of dual tunnel capable of
carrying two tracks, and how much for one tunnel large enough for both
tracks? Make any assumption you like about the specification of the trains
- e.g. Circle line standard.

The Circle is an Underground (sub surface) line - mainly cut and cover.

The deep tubes are bored.

You can take a tube train on the underground but you can't take an
underground train down the tube ...

--

Terry

The Natural Philosopher wrote:
Tim Streater wrote:
In article , Doctor Drivel
wrote:

A scab is a SCAB.

So tell us, drivel, what should happen to a scab (or be done to
them)?

pick them and eat them.

That's warts.

--
Adam

On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel capable
of carrying two tracks, and how much for one tunnel large enough for
both tracks? Make any assumption you like about the specification of
the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

--
Rod

On Sun, 01 Jan 2012 21:12:10 -0000, Terry Casey
wrote:

In article ,
says...

On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:



Its cheaper to bore one tunnel these days.


How much would it cost to bore, says, one mile of dual tunnel capable of
carrying two tracks, and how much for one tunnel large enough for both
tracks? Make any assumption you like about the specification of the
trains
- e.g. Circle line standard.

The Circle is an Underground (sub surface) line - mainly cut and cover.

The deep tubes are bored.

You can take a tube train on the underground but you can't take an
underground train down the tube ...


But I did offer him the choice of any size - Central line if he wishes. Or
Glasgow's orange worms.

--
Rod

On Sun, 01 Jan 2012 20:00:24 -0000, dennis@home
wrote:



"polygonum" wrote in message
news
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:



Its cheaper to bore one tunnel these days.


How much would it cost to bore, says, one mile of dual tunnel capable
of carrying two tracks, and how much for one tunnel large enough for
both tracks? Make any assumption you like about the specification of
the rains - e.g. Circle line standard.

That depends on the boring machine and the stuff its boring through.

But at a rough guess..

One machine + crew vs. two machines + crew so probably near double for
two tunnels.
It might be one machine + one crew boring two miles in which case it
might work out a bit less than double but take twice as long.

I can't see why a large machine would need a bigger crew so its not
going to cost significantly more.

A large tunnel would also mean a lot more space for services, etc. so
may well work out even cheaper.

Might not the number of people involved have some relation to the volume
to be extracted? Sort of one person to drive one lorry carry one
lorryload, or two people to drive out twice as much? Obviously not a
perfect scaling - indeed lorry sizes might vary - but it is likely to be
soothing like that.

Trying to recoup extra costs by providing extra facilities is fine on
overall project costs -but you were going on about costs of boring.

--
Rod

"polygonum" wrote in message
news
Might not the number of people involved have some relation to the volume
to be extracted? Sort of one person to drive one lorry carry one
lorryload, or two people to drive out twice as much? Obviously not a
perfect scaling - indeed lorry sizes might vary - but it is likely to be
soothing like that.

Bigger tunnel allows bigger lorries/conveyors in the tunnel so no extra crew
needed.
Dumping the spoils depends on where and how, a train would still have the
same number of crew, lorries may need more.


Trying to recoup extra costs by providing extra facilities is fine on
overall project costs -but you were going on about costs of boring.

Well I suppose you could try and win by doing half a job.

Doctor Drivel wrote:

"hugh" ] wrote in message
...
In message , "Dave Plowman (News)"
writes
In article ,
Doctor Drivel wrote:
Nonsense. Heavy trucks roll down hills and up the other side very well.

Yet another example to prove you can't even drive.

Trucks on a motorway run at a constant governed speed. If they
haven't got
enough power, they slow down on hills. Hence crawler lanes. Any kinetic
energy can safely be ignored in practice.

When going down hill the brakes may be applied to prevent them
exceeding the governed speed so there is little excess KE to carry
them forward.

Freewheeling the roll down and up very well.

I've done the experiment. Now *you* go and do it. Report back. My
results can be found upthread aways.

--
Tciao for Now!

John.

polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel
capable of carrying two tracks, and how much for one tunnel large
enough for both tracks? Make any assumption you like about the
specification of the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

Four times, as doubling the bore diameter increases the bore area by
four times. So, boring a double track tunnel costs twice as much
(roughly) per route mile as two single track tunnels. The tunnel walls
also have to be built stronger, increasing the costs further.

There is also the disadvantage, if it's a new scheme under a city, that
the larger tunnel has far more restricted routing options, as it is
harder to avoid obstacles like sewers, pipes and cables, not to mention
the fact that any building it goes under will need much more expensive
underpinning work than with two single track tunnels.

The *only* time a double track tunnel is cheaper to build than two
singles is when you use a cut and cover system, as used for much of the
Paris Metro, and most of that follows the surface street layout, so
dodging the problems of access under buildings and supporting them after
you dig the hole.

--
Tciao for Now!

John.

dennis@home wrote:


"Doctor Drivel" wrote in message
...

I don't see how this is any more expensive than boring tunnels without
the gradients ...

I can, unless the trains only run one way.
You would need two tunnels to do it in both directions.

That is what they do. Two tunnels is also for safety reasons.

Which is more expensive, making me correct.

I wouldn't be so sure.

polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel
capable of carrying two tracks, and how much for one tunnel large
enough for both tracks? Make any assumption you like about the
specification of the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

yerss but the bigger tunnel doesn't have to be 1.4 the diameter..its an
interesting thing really..I don't know how the actual tunnel 'fits' the
trains.

John Williamson wrote:
polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel
capable of carrying two tracks, and how much for one tunnel large
enough for both tracks? Make any assumption you like about the
specification of the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

Four times, as doubling the bore diameter increases the bore area by
four times. So, boring a double track tunnel costs twice as much
(roughly) per route mile as two single track tunnels. The tunnel walls
also have to be built stronger, increasing the costs further.

Not necessarily.

Single tunnels have a lot more diameter than the train, but a double
tunnel will be a lot closer to 2 trains.

There is also the disadvantage, if it's a new scheme under a city, that
the larger tunnel has far more restricted routing options, as it is
harder to avoid obstacles like sewers, pipes and cables, not to mention
the fact that any building it goes under will need much more expensive
underpinning work than with two single track tunnels.

The *only* time a double track tunnel is cheaper to build than two
singles is when you use a cut and cover system, as used for much of the
Paris Metro, and most of that follows the surface street layout, so
dodging the problems of access under buildings and supporting them after
you dig the hole.

Not true. It is a very complex mix of machine sizes, cutting speeds
materaial and labour costs.

For sure when you go straight down with a cut and cover you get the
least material removed and the smallest footprint from a single tunnel.

So that will in general be CHEAPER than two.

When tunelling - well maybe the machines only do a single train sized
tunnel.

"John Williamson" wrote in message
...
polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel capable
of carrying two tracks, and how much for one tunnel large enough for
both tracks? Make any assumption you like about the specification of
the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

Four times, as doubling the bore diameter increases the bore area by four
times. So, boring a double track tunnel costs twice as much (roughly) per
route mile as two single track tunnels. The tunnel walls also have to be
built stronger, increasing the costs further.

That isn't always true.
To start with you don't need twice the diameter to run two tracks.
The boring machine would be bigger and will be capable of boring faster as
you can get more works into the machine than a small one.


There is also the disadvantage, if it's a new scheme under a city, that
the larger tunnel has far more restricted routing options, as it is harder
to avoid obstacles like sewers, pipes and cables, not to mention the fact
that any building it goes under will need much more expensive underpinning
work than with two single track tunnels.

This is a tunnel, you normally go under the services.
Its cut and cover where you hit big problems with sewers, traffic, etc. It
also disturbs a lot of surrounding ground as it buggers up the water table.
You really wouldn't want to do a 100 foot deep cut and cover in London.

You don't need to underpin if the tunnel is done properly at a sensible
depth.



The *only* time a double track tunnel is cheaper to build than two singles
is when you use a cut and cover system, as used for much of the Paris
Metro, and most of that follows the surface street layout, so dodging the
problems of access under buildings and supporting them after you dig the
hole.

On Sun, 01 Jan 2012 18:43:53 -0000 Polygonum wrote :
How much would it cost to bore, says, one mile of dual tunnel capable
of carrying two tracks, and how much for one tunnel large enough for
both tracks? Make any assumption you like about the specification of
the trains - e.g. Circle line standard.

Wouldn't one larger tunnel have safety issues - thinking of the Channel
Tunnel where you escape from the running tunnels into the service tunnel

--
Tony Bryer, Greentram: 'Software to build on',
Melbourne, Australia www.greentram.com

"Terry Casey" wrote in message
...
In article ,
says...

On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:

Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel capable of
carrying two tracks, and how much for one tunnel large enough for both
tracks? Make any assumption you like about the specification of the
trains
- e.g. Circle line standard.

The Circle is an Underground (sub surface) line - mainly cut and cover.

The deep tubes are bored.

You can take a tube train on the underground but you can't take an
underground train down the tube ...

That is rather pedantic. Both are tunnels no matter how they are
constructed. Cut and cover is superb, as in Paris, as the stations are just
below ground level and can be only be a few steps down. Some Paris platforms
can be seen from the street pavement. People just hop and off the quiet
trains with rubber wheels.

The first deep level underground railway was the Mersey Railway under a very
deep and wide estuary - 90 foot deep at low tide at one point. The stations
at each end are so deep, around 130 foot, that only lifts could be used -
the escalator was not in general use at the time. The stations were also
the first deep stations - not cut & cover.

Two tunnels are used for obvious safety reasons. With an accident in one
tunnel there is access to the next via fire doors for evacuation and
emergency services access - look at the Liverpool Kingsway road tunnel.
Tunnels is cheap these days -no land purchases and NIMBY court cases making
delays.

The Natural Philosopher wrote:
polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel
capable of carrying two tracks, and how much for one tunnel large
enough for both tracks? Make any assumption you like about the
specification of the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

yerss but the bigger tunnel doesn't have to be 1.4 the diameter..its an
interesting thing really..I don't know how the actual tunnel 'fits' the
trains.

Very tightly:-

http://en.wikipedia.org/wiki/File:Wh...The_Tube. jpg

--
Tciao for Now!

John.

On Mon, 02 Jan 2012 09:17:12 -0000, John Williamson
wrote:

The Natural Philosopher wrote:
polygonum wrote:
On Sun, 01 Jan 2012 21:00:46 -0000, The Natural Philosopher
wrote:

polygonum wrote:
On Sun, 01 Jan 2012 18:30:22 -0000, dennis@home
wrote:


Its cheaper to bore one tunnel these days.

How much would it cost to bore, says, one mile of dual tunnel
capable of carrying two tracks, and how much for one tunnel large
enough for both tracks? Make any assumption you like about the
specification of the trains - e.g. Circle line standard.

essentially about 50% more material at a wet finger guess has to be
removed if the tunnel is circular.

I guessed around twice as much using simplistic pi r squared.

yerss but the bigger tunnel doesn't have to be 1.4 the diameter..its
an interesting thing really..I don't know how the actual tunnel 'fits'
the trains.

Very tightly:-

http://en.wikipedia.org/wiki/File:Wh...The_Tube. jpg

Certainly the clearance between the trains and the inner tunnel wall is
incredibly small. But when tunnelling it is surely necessary to consider
the outer wall? What does that add? Maybe a metre or two to diameter?

--
Rod

On Mon, 02 Jan 2012 04:22:31 -0000, Tony Bryer
wrote:

On Sun, 01 Jan 2012 18:43:53 -0000 Polygonum wrote :
How much would it cost to bore, says, one mile of dual tunnel capable
of carrying two tracks, and how much for one tunnel large enough for
both tracks? Make any assumption you like about the specification of
the trains - e.g. Circle line standard.

Wouldn't one larger tunnel have safety issues - thinking of the Channel
Tunnel where you escape from the running tunnels into the service tunnel

Indeed it would. But I started out questioning the assertion that one
larger tunnel is cheaper to bore than two small. Your point adds to the
rationale. Though if there needs to be a parallel safety tunnel, maybe
that could be the same whether for one large tunnel or both both small
tunnels.

--
Rod

On Sun, 01 Jan 2012 21:12:10 -0000, Terry Casey
wrote:


The Circle is an Underground (sub surface) line - mainly cut and cover.

The deep tubes are bored.

You can take a tube train on the underground but you can't take an
underground train down the tube ...


Actually I remember hearing about a British Rail track recording coach
being taken through part of the LU network. Must have been in the 1980s.
Did a little damage at the ends of the coach - and to the tunnel - but
nothing too bad. Not sure if they pursued the idea of sharing the resource.

--
Rod