"Bondee" wrote in message
...

"Paul Scott" wrote in message
...

Where does that underpass come out then, I can't see any sign of it on
the north of the tracks?

I'm not sure. I've never really paid any attention to the area until I
read about the bridge collapse. It's not a footpath from the golf course,
is it? I guess the entrance on the other side would be hidden by the
trees.


A good quality picture of the failure has appeared on the Network Rail site
now:

http://www.nationalrail.co.uk/servic...idge_Nov09.JPG

Paul S

In message
"Paul Scott" wrote:


"Bondee" wrote in message
...

"Paul Scott" wrote in message
...

Where does that underpass come out then, I can't see any sign of it on
the north of the tracks?

I'm not sure. I've never really paid any attention to the area until I
read about the bridge collapse. It's not a footpath from the golf
course, is it? I guess the entrance on the other side would be hidden by
the trees.


A good quality picture of the failure has appeared on the Network Rail site
now:

http://www.nationalrail.co.uk/servic...idge_Nov09.JPG


Nasty!

--
Graeme Wall

This address not read, substitute trains for rail
Transport Miscellany at www.greywall.demon.co.uk/rail

On Wed, 18 Nov 2009 16:02:37 -0000, "Paul Scott"
wrote:
A good quality picture of the failure has appeared on the Network Rail site
now:
http://www.nationalrail.co.uk/servic...idge_Nov09.JPG


A couple of tubes of decorator's filler, and the job's a good 'un.

On Fri, 20 Nov 2009 02:07:19 -0600,
wrote:

Hmm. Looks to me like part of the top of the arch was filled with rubble.
LSWR jerry building?


The spandrels were always filled with rubble.

Next question?

In article ,
(Bruce) wrote:

On Fri, 20 Nov 2009 02:07:19 -0600,
wrote:

Hmm. Looks to me like part of the top of the arch was filled with
rubble. LSWR jerry building?

The spandrels were always filled with rubble.

Next question?

OK as long as there is enough structural brickwork containing it, Clearly
there wasn't here.

--
Colin Rosenstiel

wrote:
In article ,
(Bruce) wrote:

On Fri, 20 Nov 2009 02:07:19 -0600,
wrote:

Hmm. Looks to me like part of the top of the arch was filled with
rubble. LSWR jerry building?

The spandrels were always filled with rubble.

Next question?

OK as long as there is enough structural brickwork containing it,
Clearly there wasn't here.

Quite, what sort of cowboys would build a bridge that would only last 161
years.

--
We are the Strasbourg. Referendum is futile.

On Wed, 18 Nov 2009 16:19:28 -0600,
wrote:

In article ,
(Bruce) wrote:

On Fri, 20 Nov 2009 02:07:19 -0600,
wrote:

Hmm. Looks to me like part of the top of the arch was filled with
rubble. LSWR jerry building?

The spandrels were always filled with rubble.

Next question?

OK as long as there is enough structural brickwork containing it, Clearly
there wasn't here.


"Clearly" there was, because the spandrel walls have successfully
contained their rubble fill for a very long time.

Basil Jet suggests 361 years! ;-)

wrote on 18 November 2009 23:19:28 ...
In article ,
(Bruce) wrote:

On Fri, 20 Nov 2009 02:07:19 -0600,
wrote:

Hmm. Looks to me like part of the top of the arch was filled with
rubble. LSWR jerry building?

The spandrels were always filled with rubble.

Next question?

OK as long as there is enough structural brickwork containing it, Clearly
there wasn't here.

You're talking as though the problem is insufficient brickwork at the
top of the arch. But it's clear from the photo that the failure occurred
lower down, where a great mass of brickwork has moved. Looks like a
gross failure of the foundations.

I wonder why it was necessary to renew so much of the brickwork at the
top of the arch (different colour bricks obvious in photo). This is
pure speculation, but I'm wondering whether there was some earlier
instability of the foundations that resulted in some movement higher up,
which was just patched up rather than properly investigated.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)

On Wed, 18 Nov 2009 23:18:36 GMT, "Richard J."
wrote:

You're talking as though the problem is insufficient brickwork at the
top of the arch. But it's clear from the photo that the failure occurred
lower down, where a great mass of brickwork has moved. Looks like a
gross failure of the foundations.


Indeed it does. It is probably a result of scour under the
foundations as a result of the extreme flows of water.


I wonder why it was necessary to renew so much of the brickwork at the
top of the arch (different colour bricks obvious in photo). This is
pure speculation, but I'm wondering whether there was some earlier
instability of the foundations that resulted in some movement higher up,
which was just patched up rather than properly investigated.


More likely, a combination of gradual long term settlement of the
structure (it appears to be very old) and frost damage to the
brickwork. Problems can then be caused by using hard modern bricks
and hard cement mortar, rather than the hand made clay bricks and
slightly flexible lime mortar that would have been used in the
original structure.

Bruce wrote:
On Wed, 18 Nov 2009 23:18:36 GMT, "Richard J."
wrote:
You're talking as though the problem is insufficient brickwork at the
top of the arch. But it's clear from the photo that the failure occurred
lower down, where a great mass of brickwork has moved. Looks like a
gross failure of the foundations.


Indeed it does. It is probably a result of scour under the
foundations as a result of the extreme flows of water.


I wonder why it was necessary to renew so much of the brickwork at the
top of the arch (different colour bricks obvious in photo). This is
pure speculation, but I'm wondering whether there was some earlier
instability of the foundations that resulted in some movement higher up,
which was just patched up rather than properly investigated.


More likely, a combination of gradual long term settlement of the
structure (it appears to be very old) and frost damage to the
brickwork. Problems can then be caused by using hard modern bricks
and hard cement mortar, rather than the hand made clay bricks and
slightly flexible lime mortar that would have been used in the
original structure.

I don't go with 'constant change' theory. More like a typical foundation
that has been undermined by a particular rainfall event. In the photo
you can see the head loss in the stream and associated turbulence with
eroding power. Once the foundations start to go, there is nothing to
hold up abutment, and then the arch fails.
Numbers of such brick culverts fail, often to be replaced by piled
foundations set further back, and concrete beams spanning the gap and
redundant footings. I remember a serious failure near Godalming, in
'68?, and i know of a place where it is possible to walk beneath a main
line on the footings of an old culvert, with concrete beams of a good
few metres now spanning a much larger gap.

Jim Chisholm