On Thu, Jun 27, 2019 at 01:38:13PM +0100, Basil Jet wrote:

I've always wondered if there is any advantage in having a multi-track
bridge as opposed to several single track bridges with inch gaps between
them. You'd think narrow bridges would be preferable with respect to
maintenance, and also preferable in most conceivable catastrophes, but
one wide bridge seems to be the usual choice.

I would expect one wide bridge to do a better job of distributing load.

Here http://www.semgonline.com/RlyMag/ReconstructionOfGrosvenorBridge.pdf
is a non-technical article about how the current bridge(s) was built.

If you can get access then there are a lot more details he
https://www.icevirtuallibrary.com/doi/10.1680/iicep.1967.8471

--
David Cantrell | top google result for "topless karaoke murders"

engineer: n. one who, regardless of how much effort he puts in
to a job, will never satisfy either the suits or the scientists

On 23/06/2019 13:44, wrote:
Saw this as I took a rare trip up to cockfosters today, never noticed it
before - must have been behind vegetation. There's very little about in
online other than it was meant to defend the depot. I'm no military expert
but I can't really see what its purpose would have been. If the germans
had got to cockfosters then it would have been game over for the tube and
probably the country so what was the point?

Anyway here's a google maps link:

https://goo.gl/maps/i4A26d931KctSoVy7




I doubt that it was railway-related. There were many pillboxes nearby,
forming part of a defensive ring around London. Tank traps, too. There
were three in nearby Trent Park, alone. The one you've seen's only
railway link is probably that, because it is surrounded by railway
tracks, it hasn't been demolished !

PA

"David Cantrell" wrote in message
k...
On Tue, Jun 25, 2019 at 04:02:38PM +0100, Guy Gorton wrote:

The only links Gatehampton has with transport.London is that the
Thames is flowing towards London and the railway is running away from
Paddington! But that is my excuse for mentioning this lovely viaduct
by Brunell which was built at two diffrent times, using different
brickwork techniques, the two being attached to each other their full
length.

The Grosvenor bridges crossing the Thames outside Victoria were built
similarly, one track at a time, so that the old structure could be
replaced without having to close Victoria station.


The current London Bridge was built as four bridges: the outer spans were
built first, either side of the old bridge, and the traffic was transferred
onto them. Then the old bridge was dismantled and the inner spans built to
fill the gap.

--
DAS