Magic Wall at Farringdon
 

The new Thameslink station has been opened. There are some nice old
bits that I don't ever remember being there (http://
http://www.southernelectric.org.uk/t...age201211.jpg),
but there's also this : http://www.southernelectric.org.uk/t...hall201211.jpg

That's a nice marble-like wall on one side of the ticket hall. Except,
the thing is, the ticket hall is also supposed to be an entrance to
Crossrail, with the escalators going straight through that wall.

So either they've built a huge expensive glossy wall, just before they
need to demolish part of it, or the wall somehow has the ability to
easily vanish, without drilling.

So what's going on with the wall?

Magic Wall at Farringdon
 

In message
,
lonelytraveller writes

That's a nice marble-like wall on one side of the ticket hall. Except,
the thing is, the ticket hall is also supposed to be an entrance to
Crossrail, with the escalators going straight through that wall.

Is it just a "marble-effect" wall? It's many years before the Crossrail
part of Farringdon will open, so they presumably need something fairly
substantial to separate passengers from the ongoing works in the
meantime.

--
Paul Terry

Magic Wall at Farringdon
 

"lonelytraveller" wrote in
message
...
The new Thameslink station has been opened. There are some nice old
bits that I don't ever remember being there (http://
http://www.southernelectric.org.uk/t...age201211.jpg),

You wouldn't remember that area, because it wasn't accessible to the public.
Previously it was mostly a solid pier supporting the two arched bridges that
support the station above, with a store room or something in its north end,
but it was beyond the normal stop position of an 8 car train heading
southbound, and alongside the Moorgate junction pointwork. From the
planning drawings it looks as though the south end of that passageway has
been opened out from the original solid construction.

The stairs just next to it on the central island have also moved northwards
a few metres as part of the northward expansion of the LU ticket hall, which
makes it more visible, and the area immediately to the south of it has been
opened right out, because they were able to demolish the bridge that
supported Cowcross St and replace it with a modern equivalent in concrete.
To have got rid of the narrow sections completely would have meant
demolition and rebuild of the whole of the LU ticket hall - and this was not
permitted by the local authority.

The effect of all this is that the platform width alongside these original
brick arches is marginally under the minimum, something like 2.3m
(where the required width is 2.5m), and this has been given a derogation...

Paul S

Magic Wall at Farringdon
 

"lonelytraveller" wrote in
message
...

So either they've built a huge expensive glossy wall, just before they
need to demolish part of it, or the wall somehow has the ability to
easily vanish, without drilling.

So what's going on with the wall?

Found this picture of the works at Blackfriars, since posting the earlier
reply, which may be relevant to this. Shows how a fairly solid looking
stone wall can be fabricated. No guarantees that the wall at Farringdon is
exactly the same but it seems quite possible:

http://www.flickr.com/photos/ianvisi...n/photostream/

Paul S

Magic Wall at Farringdon
 

"Paul Scott" wrote:

"lonelytraveller" wrote in
message
...

So either they've built a huge expensive glossy wall, just before they
need to demolish part of it, or the wall somehow has the ability to
easily vanish, without drilling.

So what's going on with the wall?

Found this picture of the works at Blackfriars, since posting the earlier
reply, which may be relevant to this. Shows how a fairly solid looking
stone wall can be fabricated. No guarantees that the wall at Farringdon is
exactly the same but it seems quite possible:

http://www.flickr.com/photos/ianvisi...n/photostream/


The picture is a very good illustration of a technique known as
"curtain walling" which is used very extensively in modern office
buildings. A light and very efficient steel or aluminium structure
carries glass or thin stone panels or a combination of the two. There
is some adjustment available in the metal structure to cater for the
tolerances of the (usually) reinforced concrete structure and give a
near-perfect finished building.

It has also been used to re-clad some older buildings, changing their
appearance and adding modern standards of weather protection. Some
pretty awful 1960s offices and blocks of flats have been brought up to
date in this way.

The stone panels are mostly produced in Italy and Norway. Large stone
blocks are very carefully quarried so they come out square. Then the
blocks - usually either granite or marble - are precision sawn using
large diameter diamond-tipped circular saws. The thickness is
typically a couple of centimetres, but the finished job often looks as
though it is made of solid granite or marble that is tens of
centimetres thick.

Magic Wall at Farringdon
 

On Feb 25, 6:53*pm, Bruce wrote:
The stone panels are mostly produced in Italy and Norway. *Large stone
blocks are very carefully quarried so they come out square. *Then the
blocks - usually either granite or marble - are precision sawn using
large diameter diamond-tipped circular saws. *The thickness is
typically a couple of centimetres, but the finished job often looks as
though it is made of solid granite or marble that is tens of
centimetres thick.

So its is actual stone, just very thin?

Clever. So when did they start using this instead of those blue mdf
walls? Will they be doing this in future, when they have building
works (at bond street, for example, or TCR) ?

Magic Wall at Farringdon
 

In message
, at
04:36:41 on Sun, 26 Feb 2012, lonelytraveller
remarked:
The stone panels are mostly produced in Italy and Norway. *Large stone
blocks are very carefully quarried so they come out square. *Then the
blocks - usually either granite or marble - are precision sawn using
large diameter diamond-tipped circular saws. *The thickness is
typically a couple of centimetres, but the finished job often looks as
though it is made of solid granite or marble that is tens of
centimetres thick.

So its is actual stone, just very thin?

Not much different to floor tiles (applied to the wall).
--
Roland Perry

Magic Wall at Farringdon
 

lonelytraveller wrote:

On Feb 25, 6:53*pm, Bruce wrote:
The stone panels are mostly produced in Italy and Norway. *Large stone
blocks are very carefully quarried so they come out square. *Then the
blocks - usually either granite or marble - are precision sawn using
large diameter diamond-tipped circular saws. *The thickness is
typically a couple of centimetres, but the finished job often looks as
though it is made of solid granite or marble that is tens of
centimetres thick.

So its is actual stone, just very thin?


Yes, that's exactly what it is. The diamond tipped circular saws are
huge and cut extremely accurately. After cutting, the stone panels
are polished on one side and the edges. The thinnest panels I have
seen were 10mm thick, but there may be thinner ones - they make
granite and marble tiles that are probably thinner.

My interest in the subject came from buying tens of thousands of
tonnes of granite waste from the Norwegian and Swedish stone quarries
to be used in sea defence works. The wastage is tremendous; the
quarry I dealt with most only managed to turn 7% of its output into
monumental stone, so 93% went to waste. They originally offered the
waste for free, so all we had to do was send barges to collect it, but
they subsequently got very organised and sorted it into weight bands,
and charged for it. But it was still comparatively cheap as all they
wanted to do was get rid of it so their quarries weren't choked with
waste stone.


Clever. So when did they start using this instead of those blue mdf
walls? Will they be doing this in future, when they have building
works (at bond street, for example, or TCR) ?


I have no idea, sorry.

Magic Wall at Farringdon
 

wrote:
On Sat, 25 Feb 2012 18:53:23 +0000, Bruce
wrote:
The picture is a very good illustration of a technique known as
"curtain walling" which is used very extensively in modern office
buildings. A light and very efficient steel or aluminium structure
carries glass or thin stone panels or a combination of the two. There
is some adjustment available in the metal structure to cater for the
tolerances of the (usually) reinforced concrete structure and give a
near-perfect finished building.

It has also been used to re-clad some older buildings, changing their
appearance and adding modern standards of weather protection.

Leaning on the wall of an 18th century house in a Dorset town this
week, while the missus did some shopping I passed the time as I often
do by looking at the buildings ,rooflines are often interesting but
this case a modern drainpipe repair had damaged the materials of the
front and showed that it was not Brick but Mathematical Tiles a
forerunner of these modern techniques.
More details here for those who are interested
http://en.wikipedia.org/wiki/Mathematical_tile

Often buildings are not what they seem at first glance.


I have had a fascination with mathematical tiling ever since staying
in a house in Brighton that was faced with them.

The Wikipedia article is interesting and is illustrated with some
excellent examples, however it completely avoids any mention of the
derivation of the term "mathematical".

The term comes from the great precision with which the tiles needed to
be made. Unlike roof tiles, which overlap and can cope with quite
large variations in dimensions, and bricks, whose unevenness is
routinely corrected by each mortar layer, mathematical tiles need to
be fairly precisely made.

As the obsessive pedants will no doubt point out, there are probably
better terms than 'mathematical', but that is what they were called.