"asdf" wrote

I'm not familiar with the economics involved, but I suppose tunnelling
would be out of the question?

Not a motorway, but a very busy D3 trunk road - a railway has just been
tunnelled under the A2 at Southfleet (CTRL Phase 2). Not that long ago, the
Thames Flood Relief Channel was constructed under the M4 and the GWML at
Taplow.

Peter

TheOneKEA wrote:

Graeme Wall wrote:
(unsnip)
John B wrote:

That would be the cause of the disruptive alterations. It's generally
frowned upon to build a new bridge over an operating motorway...

???

What about all those motorway junctions that acquired extra bridges when
they were roundaboutized above the motorway?

Easy enough, prefabricate the thing alongside, close the road overnight and
swing the thing into position when ready. Not exactly rocket science.

Ah, but no one has yet mentioned the fact that the M40 crosses the
formation _on_the_level_. The A40 does not, and still has the bridge
abutments to prove it, but the M40 apparently foes right over the
formation, and too closely to the A40 to allow for easy gradients.

So unless a horrific gradient was contemplated, the M40 would have to
be lowered to the same level as the A40, which would cost $WAY_TOO_MUCH.

That's a very strange conclusion!

Obviously the new track would be higher than the old formation, to
enable it to bridge both roads easily. Is there any good reason why
cranes could not lift the prefabricated deck into position overnight (or
even over several nights)?

--
Aidan Stanger
http://www.bettercrossrail.co.uk

In message .com
"TheOneKEA" wrote:

Graeme Wall wrote:
Easy enough, prefabricate the thing alongside, close the road overnight
and swing the thing into position when ready. Not exactly rocket
science.

Ah, but no one has yet mentioned the fact that the M40 crosses the
formation _on_the_level_. The A40 does not, and still has the bridge
abutments to prove it, but the M40 apparently foes right over the
formation, and too closely to the A40 to allow for easy gradients.

So unless a horrific gradient was contemplated, the M40 would have to
be lowered to the same level as the A40, which would cost $WAY_TOO_MUCH.


AHBLC :-)

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

In message
Tom Anderson wrote:

On Thu, 2 Mar 2006, Graeme Wall wrote:

In message . com
"John B" wrote:

Aidan Stanger wrote:

And a new/relaid line from Princes Risborough to Oxford.

will never happen, as it would require too many disruptive
alterations to the M40 at Junction 8.

Why would it require any at all? Surely it could just bridge it?

That would be the cause of the disruptive alterations. It's generally
frowned upon to build a new bridge over an operating motorway...

Easy enough, prefabricate the thing alongside, close the road overnight
and swing the thing into position when ready.

I'd hesitate to say it's that simple - things on that scale never are -
but then that's not so far from what they did with the Bishops Bridge at
Paddington:

http://www.paddingtonbridge.com/view...ion/index.html

Love the whip pans at the start!

Not exactly rocket science.

No, civil engineering - much harder!


But something civil engineers have been doing for decades. I agree that
rocket science is easy, it's rocket technology that's complicated.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

Peter Masson wrote:

"TheOneKEA" wrote

I suspect that with extensive improvements to the LNWR route between
Oxford and Bicester Town, combined with a decent curvature and gradient
on the chord, you could get competitive journey times between Oxford
and Marylebone. Plus of course, you get the onward links between Oxford
and High Wycombe, Risborough and Aylesbury.

Unfortunately though I think FGW has cornered the Oxford-London market,
so the chord might only get built on the strength of depopulating the
M40 of people driving from Buckinghamshire to Oxford for work or school.

I can't see how Chiltern can possibly compete for London to Oxford traffic.
FGW can get there in 52 minutes, and if it had to compete on speed could do
the journey non-stop in no more than 45 minutes. Chiltern's best time,
non-stop, to Bicester is 50 minutes. It seems to me that Chiltern, like the
Metropolitan before them, have got mesmerised with Oxford as a destination.
They realise that they've got no chance of reopening via Thame; Aston Rowant
Parkway seems to be a non-starter, and going via Bicester comes into the
category of Great Way Round. Perhaps Chiltern need to build a spur on to the
trackbed of the Brill Tramway and dust off the Met's scheme for extending
this to Oxford. ;-)

Peter

When this topic came up on an earlier thread I suggested that if
Chiltern were to build a North Oxford Parkway station on the Bicester
line, it might prove attractive to residents of Witney, Woodstock,
Kidlington and surrounding areas. They could get a train to London
without having to negotiate Oxford's traffic and the door-to-door
journey time might be competative.

Andy

Peter Masson ) gurgled happily, sounding much
like they were saying :

I can't see how Chiltern can possibly compete for London to Oxford
traffic. FGW can get there in 52 minutes, and if it had to compete on
speed could do the journey non-stop in no more than 45 minutes.
Chiltern's best time, non-stop, to Bicester is 50 minutes. It seems to
me that Chiltern, like the Metropolitan before them, have got
mesmerised with Oxford as a destination.

Look at the popularity of the Oxford Tube coaches - no WAY are they getting
to central london in 50 mins at rush hour...

"Approx travel time 100mins, longer in rush hour". But - they're cheap.
£11/£13 return.

"Graeme Wall" wrote in message
...
In message

Not exactly rocket science.

No, civil engineering - much harder!


But something civil engineers have been doing for decades. I agree that
rocket science is easy, it's rocket technology that's complicated.

As an undergrad, I had to live with a couple of civil engineer undergrads
too. They would frequently use the expression "It's not rocket science!" -
until one day they had to do coursework on matlab. It was completely beyond
one of them, and the expression was rapidly changed to "It's not matlab!"


--
Ronnie
--
www.greatcentralrailway.com
Adjust the farmyard animals before replying

Ronnie Clark wrote:
"Graeme Wall" wrote in message
...
In message

Not exactly rocket science.

No, civil engineering - much harder!


But something civil engineers have been doing for decades. I agree that
rocket science is easy, it's rocket technology that's complicated.

As an undergrad, I had to live with a couple of civil engineer undergrads
too. They would frequently use the expression "It's not rocket science!" -
until one day they had to do coursework on matlab. It was completely beyond
one of them, and the expression was rapidly changed to "It's not matlab!"


--
Ronnie
--
www.greatcentralrailway.com
Adjust the farmyard animals before replying

Given that with the exception of the Begal Martian probe they can send
something into deep space over many years and it function correctly
then the saying should be changed to "it isn't Goverment IT contract
science".

Kevin

In uk.railway Graeme Wall wrote:
Easy enough, prefabricate the thing alongside, close the road overnight and
swing the thing into position when ready. Not exactly rocket science.

A bridge launch can be pretty quick. Some of the GCR engineering folk
visited the CTRL works in London a few years back on Xmas day to watch
one of their bridges being launched over existing rail lines. They
said that it was all over in a couple of hours - a metre or so every
few minutes.

Jim'll

"Andy Kirkham" wrote:

When this topic came up on an earlier thread I suggested that if
Chiltern were to build a North Oxford Parkway station on the Bicester
line, it might prove attractive to residents of Witney, Woodstock,
Kidlington and surrounding areas. They could get a train to London
without having to negotiate Oxford's traffic and the door-to-door
journey time might be competative.


It was, and still is, a *very* good idea.