In message .com, MIG
writes

At London Bridge (and still at Bank) the wall between (or in the
middle of the island) platorms was much thinner than at most similar
stations.

In the case of London Bridge, the gap between the tunnels was small
because there was no station there at all on the original line -
presumably the City and South London thought that people would find it
quicker to walk over London Bridge than take a very short one-stop
journey to their King William Street terminus at the north end of the
bridge.

--
Paul Terry

Paul Terry wrote:

At London Bridge (and still at Bank) the wall between (or in the
middle of the island) platorms was much thinner than at most similar
stations.

In the case of London Bridge, the gap between the tunnels was small
because there was no station there at all on the original line -
presumably the City and South London thought that people would find it
quicker to walk over London Bridge than take a very short one-stop journey
to their King William Street terminus at the north end of the bridge.

I thought London Bridge was on the replacement tunnel when it was decided to
extend the line north and abandon King William Street? Isn't the original
tunnel directly above, providing ventilation?

On 9 Feb, 10:16, "Tim Roll-Pickering"
wrote:
Paul Terry wrote:
At London Bridge (and still at Bank) the wall between (or in the
middle of the island) platorms was much thinner than at most similar
stations.
In the case of London Bridge, the gap between the tunnels was small
because there was no station there at all on the original line -
presumably the City and South London thought that people would find it
quicker to walk over London Bridge than take a very short one-stop journey
to their King William Street terminus at the north end of the bridge.

I thought London Bridge was on the replacement tunnel when it was decided to
extend the line north and abandon King William Street? Isn't the original
tunnel directly above, providing ventilation?


That's more plausible. It if had been just running tunnels there
would be no room for platforms at all. They'd have to be on the
outside, as when a new station was built round the running tunnels at
Holborn on the Central.

Incidentally, most of the Bakerloo stations were built without island
platforms, perhaps because the whole thing was done on the cheap,
except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini, but I
wonder why Trafalgar Square was built differently from the others?

On 9 Feb, 13:37, "MIG" wrote:
On 9 Feb, 10:16, "Tim Roll-Pickering"
wrote:

Paul Terry wrote:
At London Bridge (and still at Bank) the wall between (or in the
middle of the island) platorms was much thinner than at most similar
stations.
In the case of London Bridge, the gap between the tunnels was small
because there was no station there at all on the original line -
presumably the City and South London thought that people would find it
quicker to walk over London Bridge than take a very short one-stop journey
to their King William Street terminus at the north end of the bridge.

I thought London Bridge was on the replacement tunnel when it was decided to
extend the line north and abandon King William Street? Isn't the original
tunnel directly above, providing ventilation?

That's more plausible. It if had been just running tunnels there
would be no room for platforms at all. They'd have to be on the
outside, as when a new station was built round the running tunnels at
Holborn on the Central.

Incidentally, most of the Bakerloo stations were built without island
platforms, perhaps because the whole thing was done on the cheap,
except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini, but I
wonder why Trafalgar Square was built differently from the others?


Why does the Bakerloo not having island platforms mean it was done on
the cheap? It's not like a passenger needs cross-platform interchange
just so they can go back the other way (though obviously it's useful
if you miss your stop but that's not a primary design consideration).

...a few moments of thought...

I guess an island platform can mean that an escalator can scoop people
up directly without them having to climb any stairs to a lobby, which
I guess makes the whole experience of entering and exiting a station a
bit more seamless.

On Fri, 9 Feb 2007, Mizter T wrote:

On 9 Feb, 13:37, "MIG" wrote:

Incidentally, most of the Bakerloo stations were built without island
platforms, perhaps because the whole thing was done on the cheap,
except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini, but I
wonder why Trafalgar Square was built differently from the others?

Why does the Bakerloo not having island platforms mean it was done on
the cheap?

This doesn't make sense to me either. I can't think of any reason an
island platform would be more expensive - rather, it should be cheaper,
since you need to build half as many stairways, chocolate machines, etc.

It's not like a passenger needs cross-platform interchange just so they
can go back the other way (though obviously it's useful if you miss your
stop but that's not a primary design consideration).

...a few moments of thought...

I guess an island platform can mean that an escalator can scoop people
up directly without them having to climb any stairs to a lobby, which
I guess makes the whole experience of entering and exiting a station a
bit more seamless.

Another benefit of an island is that in the same space as two separate
platforms each with a narrow staircase, you can have an island with one
wide staircase. Since trains tend not to arrive simultaneously at both
platforms, that means each arriving trainload of passengers has a nice
wide staircase to escape the platforms, rather than a narrow one.

tom

--
inspired by forty-rod whiskey

On Fri, 9 Feb 2007, MIG wrote:

Incidentally, most of the Bakerloo stations were built without island
platforms, perhaps because the whole thing was done on the cheap, except
at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini, but I
wonder why Trafalgar Square was built differently from the others?

Perhaps because it was expected to be the busiest station? I'm guessing,
but if Trafalgar Square was more of a destination than the Oxford or
Piccadilly Circenses at the time, that could be an explanation.

tom

--
inspired by forty-rod whiskey

Tom Anderson wrote:
On Fri, 9 Feb 2007, Mizter T wrote:
On 9 Feb, 13:37, "MIG" wrote:

Incidentally, most of the Bakerloo stations were built without
island platforms, perhaps because the whole thing was done on the
cheap, except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini,
but I wonder why Trafalgar Square was built differently from the
others?

Why does the Bakerloo not having island platforms mean it was done on
the cheap?

This doesn't make sense to me either. I can't think of any reason an
island platform would be more expensive - rather, it should be
cheaper, since you need to build half as many stairways, chocolate
machines, etc.

I'm guessing that it's to do with the fact that you had to remain under
public ground or pay wayleaves to the land owners above. Outside platforms
only require rectangular pieces of land either side of the running tunnels,
whereas an island platform requires a long javelin-shaped piece of land
which includes unused triangles between the platform ends and the point
where the running tunnels come together. If the line was running under a
wide road, then an island platform would be cheapest, but under a narrow
road, outside platforms would be cheaper.

On 9 Feb, 14:48, "Mizter T" wrote:
On 9 Feb, 13:37, "MIG" wrote:





On 9 Feb, 10:16, "Tim Roll-Pickering"
wrote:

Paul Terry wrote:
At London Bridge (and still at Bank) the wall between (or in the
middle of the island) platorms was much thinner than at most similar
stations.
In the case of London Bridge, the gap between the tunnels was small
because there was no station there at all on the original line -
presumably the City and South London thought that people would find it
quicker to walk over London Bridge than take a very short one-stop journey
to their King William Street terminus at the north end of the bridge.

I thought London Bridge was on the replacement tunnel when it was decided to
extend the line north and abandon King William Street? Isn't the original
tunnel directly above, providing ventilation?

That's more plausible. It if had been just running tunnels there
would be no room for platforms at all. They'd have to be on the
outside, as when a new station was built round the running tunnels at
Holborn on the Central.

Incidentally, most of the Bakerloo stations were built without island
platforms, perhaps because the whole thing was done on the cheap,
except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini, but I
wonder why Trafalgar Square was built differently from the others?

Why does the Bakerloo not having island platforms mean it was done on
the cheap? It's not like a passenger needs cross-platform interchange
just so they can go back the other way (though obviously it's useful
if you miss your stop but that's not a primary design consideration).

...a few moments of thought...

I guess an island platform can mean that an escalator can scoop people
up directly without them having to climb any stairs to a lobby, which
I guess makes the whole experience of entering and exiting a station a
bit more seamless.-


There is certainly now a handy step-free exit at Paddington, since the
escalator to the concourse. Sadly, you still have to do steps at
Trafalgar Square.

The thing about on the cheap: I don't know why. We know that the
Bakerloo was done relatively on the cheap (short platforms later
having to be extended etc), and also that it didn't mostly have island
platforms, like most of the Central did. I was guessing that there
might be a link between the two.

One possibility is the engineering requirements of moving the tunnels
apart rather than keeping them adjacent. I don't think they had the
slight rise at stations that the Central had either.

In article ,
Tim Roll-Pickering wrote:

I thought London Bridge was on the replacement tunnel when it was decided to
extend the line north and abandon King William Street? Isn't the original
tunnel directly above, providing ventilation?

Yes - see pics from before the tunnels were servered at
http://www.leverton.org/tunnels/cslr/ though unfortunately I didn't
capture the actual slots in the floor(CSLR)/roof(Northern), and nor has
anyone else that I can find on a quick Google.

The former southbound Northern line platform is seen here on Richard
Griffin's site after conversion to pedestrian use but before it was
completely panelled over: http://www.squarewheels.org.uk/rly/LUgenPhots/

I have read that you can still see up the ventilation slots from the
Northbound platform, but I rarely visit London these days so haven't
checked for myself. I imagine it must need a very tightly focussed
Maglight to reach the upper tunnel roof.

If anyone ever gets any hint of another visit to the CSLR, please please
please let me know ! :-)

Nick
--
http://www.leverton.org/ ... So express yourself

On 9 Feb, 17:41, "John Rowland"
wrote:
Tom Anderson wrote:
On Fri, 9 Feb 2007, Mizter T wrote:
On 9 Feb, 13:37, "MIG" wrote:

Incidentally, most of the Bakerloo stations were built without
island platforms, perhaps because the whole thing was done on the
cheap, except at Paddington, Elephant and Trafalgar Square.

The first two may have been different because they were termini,
but I wonder why Trafalgar Square was built differently from the
others?

Why does the Bakerloo not having island platforms mean it was done on
the cheap?

This doesn't make sense to me either. I can't think of any reason an
island platform would be more expensive - rather, it should be
cheaper, since you need to build half as many stairways, chocolate
machines, etc.

I'm guessing that it's to do with the fact that you had to remain under
public ground or pay wayleaves to the land owners above. Outside platforms
only require rectangular pieces of land either side of the running tunnels,
whereas an island platform requires a long javelin-shaped piece of land
which includes unused triangles between the platform ends and the point
where the running tunnels come together. If the line was running under a
wide road, then an island platform would be cheapest, but under a narrow
road, outside platforms would be cheaper.


Which sounds like a good bit of reasoning to me.

Perhaps foolishly I'm now going to ask what I guess amounts to a
rather big question - when were the wayleave laws changed? I
understand the basic concept of wayleaves, and also that they don't
apply to Underground railways anymore in the UK - at least not to deep-
level tube railways (as evidenced by the Jubilee and Victoria lines,
and the DLR and CTRL tunnels).

This perhaps speaks for the fact that I'm not in possession of a
library of reference books on the Underground system - I shall take a
look at the bibliography of CULG and pick out a few appropriate books
to obtain.