"Peter Lawrence" wrote in message
...

Its only getting 2 platforms for now, and continues with 2 in the
present TL Program.

I'm not sure what has happened to the 4 car SPILL layout. The station
box is big enough AIUI.

I don't think that a 4 platform station was ever envisaged here. That
was a different plan with a new station roughly on the Kings Cross
Hotel site.

While that may be correct, the failure to provide a 4-platform layout (or at
least 3 - see below) was a piece of penny-pinching which will come back to
haunt us. Remember that we were told that the provision of the station box
was an engineering masterpiece that could never be done (or changed) in the
future - it had to be done while St P was being dug up, so it was a case of
"right first time". But even with this warning, no provision was made for
island platforms. This station cries out for islands - because station dwell
time is going to be longer than any other station on the line, so the
ability to signal the next train into the opposite face of the island (even
if both faces are not occupied simultaneously) would have been excellent
even in the northbound direction, and may prove essential to the promised
frequency. Southbound it would have enabled trains to arrive simultaneously
from Bedford and Peterborough. They got this right in the 1930s at Baker
Street, with two southbound platforms, one for each branch (as it then was)
of the Bakerloo. We appear to have learnt nothing in the intervening years.

Regards

Jonathan

On Dec 2, 12:55 pm, "Jonathan Morton"
wrote:

I'm not sure what has happened to the 4 car SPILL layout. The station
box is big enough AIUI.

I don't think that a 4 platform station was ever envisaged here. That
was a different plan with a new station roughly on the Kings Cross
Hotel site.



While that may be correct, the failure to provide a 4-platform layout (or at
least 3 - see below) was a piece of penny-pinching which will come back to
haunt us.



I must be confusing things then - I thought the sequence went
something like

- 2 islands under the KX hotel site (TL2000 pre-CTRL)
- 2 islands under the present site (TL2000 modified CTRL)
- TL2000 project slippage
- TL2000 project economy 2 islands but initially equipped on inner
faces only
- still not funded
- then incorporation of box only with CTRL but no station
- late preparation of box into SPILL to coincide (as far as practical)
with CTRL opening
- but still 2 faces only and the 2 outer faces ''blanked off''
- on signalling upgrade for 24 TPH / 12 cars *points only* to be
installed
- on incorporation of GN servcies installtion of outer tracks and use
of all 4 faces


I'm sure I got that from somewhere - the term ''blanked off'' is in my
mind as I was never clear if they meant a vertical partition wall or
horizontal making a very wide platform. About 2 years ago now I was
able to visit the SPILL works site and I'm sure they were talking
islands then.


Whatever, for all the reasons in the preceding message are vaild, I
am not sure SPILL is the headway throttle. I think the very close
stations Blackfriars - City - Farringdon will be the throttle. True
you can have trains one up behind the other - as the almost do now at
Blackfriars - but the very close spacing and short distance means
there is no possibity to do any more than slow speed.

--
Nick

Jonathan Morton wrote:
"Peter Lawrence" wrote in message
...

Its only getting 2 platforms for now, and continues with 2 in the
present TL Program.

I'm not sure what has happened to the 4 car SPILL layout. The station
box is big enough AIUI.
I don't think that a 4 platform station was ever envisaged here. That
was a different plan with a new station roughly on the Kings Cross
Hotel site.

While that may be correct, the failure to provide a 4-platform layout (or at
least 3 - see below) was a piece of penny-pinching which will come back to
haunt us. Remember that we were told that the provision of the station box
was an engineering masterpiece that could never be done (or changed) in the
future - it had to be done while St P was being dug up, so it was a case of
"right first time". But even with this warning, no provision was made for
island platforms. This station cries out for islands - because station dwell
time is going to be longer than any other station on the line,

Why will the dwell times here be longer than other stations? I'd have
thought somewhere like City Thameslink or London Bridge would have just
as much excuse to have long dwell times, and wherever the location of
the voltage change also has a good reason to offer long dwell times,
what's so special about this station?

Robin

On Sun, 2 Dec 2007, Jonathan Morton wrote:

"Peter Lawrence" wrote in message
...

Its only getting 2 platforms for now, and continues with 2 in the
present TL Program.

I'm not sure what has happened to the 4 car SPILL layout. The station
box is big enough AIUI.

I don't think that a 4 platform station was ever envisaged here. That
was a different plan with a new station roughly on the Kings Cross
Hotel site.

While that may be correct, the failure to provide a 4-platform layout
(or at least 3 - see below) was a piece of penny-pinching which will
come back to haunt us. Remember that we were told that the provision of
the station box was an engineering masterpiece that could never be done
(or changed) in the future - it had to be done while St P was being dug
up, so it was a case of "right first time". But even with this warning,
no provision was made for island platforms. This station cries out for
islands - because station dwell time is going to be longer than any
other station on the line, so the ability to signal the next train into
the opposite face of the island (even if both faces are not occupied
simultaneously) would have been excellent even in the northbound
direction, and may prove essential to the promised frequency.

With you 100%.

Even building the station as an island platform and two bank platforms [1]
surrounding just two tracks, so passengers can get on on one side and off
on the other, would have been really helpful, as it would move people
faster and reduce dwell times.

Southbound it would have enabled trains to arrive simultaneously from
Bedford and Peterborough. They got this right in the 1930s at Baker
Street, with two southbound platforms, one for each branch (as it then
was) of the Bakerloo. We appear to have learnt nothing in the
intervening years.

Hang on, though - at Baker Street, the junction between the southbound
lines of the Watford and Stanmore branches is *south* of the platforms,
isn't it? That means you really can have trains from each arriving
simultaneously, with one then waiting at the platform for the other to
leave. At St Pancras, the junction of the Great Northern and Midland
branches of Thameslink has to be north of the station box, doesn't it? You
can still bring a second train in sooner than if you only had one platform
(as soon as the first train's cleared the junction, rather than left the
platform), but it's not quite the same situation.

tom

[1] Or whatever you call a normal platform - bank by riverine analogy to
island!

--
Like Kurosawa i make mad films; okay, i don't make films, but if i did
they'd have a samurai.

In message , at 13:30:27 on Mon, 3
Dec 2007, R.C. Payne remarked:

Why will the dwell times here be longer than other stations? I'd have
thought somewhere like City Thameslink or London Bridge would have just
as much excuse to have long dwell times, and wherever the location of
the voltage change also has a good reason to offer long dwell times,
what's so special about this station?

It's where two lines meet and merge. So you can only get the maximum
throughput if trains arrive from the two branches interleaved exactly on
time.
--
Roland Perry

Roland Perry wrote:
In message , at 13:30:27 on Mon, 3
Dec 2007, R.C. Payne remarked:

Why will the dwell times here be longer than other stations? I'd have
thought somewhere like City Thameslink or London Bridge would have
just as much excuse to have long dwell times, and wherever the
location of the voltage change also has a good reason to offer long
dwell times, what's so special about this station?

It's where two lines meet and merge. So you can only get the maximum
throughput if trains arrive from the two branches interleaved exactly on
time.

Is it? I thought they met and merged north of the station, and shared a
single 2 track approach from the north. If that is the case, then they
will have to interleave exactly regardless of whether the station has 2
or 4 platforms. They will be sharing a two track route through the
centre, anyway, so departure from St.P. will be intollerant anyway.

But all of this misses the point of my question, which was to query the
assertion that dwell times at St.P. will be longer than at other
stations on the route. The mere fact of lines merging shouldn't cause
longer dwell times, after all Rochester has no longer a dwell time than
Chatham, Hitchin no longer than Letchworth, so why should Kings Cross
have a longer dwell time than City Thameslink or Blackfriars?

Robin

In message , at 15:03:14 on Mon, 3
Dec 2007, R.C. Payne remarked:

Why will the dwell times here be longer than other stations? I'd
have thought somewhere like City Thameslink or London Bridge would
have just as much excuse to have long dwell times, and wherever the
location of the voltage change also has a good reason to offer long
dwell times, what's so special about this station?
It's where two lines meet and merge. So you can only get the maximum
throughput if trains arrive from the two branches interleaved exactly
on time.

Is it? I thought they met and merged north of the station, and shared
a single 2 track approach from the north. If that is the case, then
they will have to interleave exactly regardless of whether the station
has 2 or 4 platforms.

The lines from the ECML aren't in place yet, but if they merge before
the station it would make things worse.

They will be sharing a two track route through the centre, anyway, so
departure from St.P. will be intollerant anyway.

Once they have left StP, then the regulation into equal headways has
happened.

But all of this misses the point of my question, which was to query the
assertion that dwell times at St.P. will be longer than at other
stations on the route.

Is it that they will be longer, or that they will be more critical? If a
train arrives a little bit late, then you need to be able to dwell
shorter than usual to catch up.

--
Roland Perry

R.C. Payne wrote:
Roland Perry wrote:
In message , at 13:30:27 on Mon, 3
Dec 2007, R.C. Payne remarked:

Why will the dwell times here be longer than other stations? I'd have
thought somewhere like City Thameslink or London Bridge would have
just as much excuse to have long dwell times, and wherever the
location of the voltage change also has a good reason to offer long
dwell times, what's so special about this station?

It's where two lines meet and merge. So you can only get the maximum
throughput if trains arrive from the two branches interleaved exactly on
time.

Is it? I thought they met and merged north of the station, and shared a
single 2 track approach from the north. If that is the case, then they
will have to interleave exactly regardless of whether the station has 2
or 4 platforms. They will be sharing a two track route through the
centre, anyway, so departure from St.P. will be intollerant anyway.

But all of this misses the point of my question, which was to query the
assertion that dwell times at St.P. will be longer than at other
stations on the route. The mere fact of lines merging shouldn't cause
longer dwell times, after all Rochester has no longer a dwell time than
Chatham, Hitchin no longer than Letchworth, so why should Kings Cross
have a longer dwell time than City Thameslink or Blackfriars?


One of my personal gripes about the current Thameslink set up is the
hanging around outside Blackfriars when travelling Northbound on the
train from the Wimbledon loop. As there are only two platforms at
Blackfriars, the loop trains have to use up their recovery time south
of the station, until the preceding service has left. They can even
arrive early at in the Blackfriars area and then leave late due to the
preceding train being late (the ex-Brighton trains seeming to get
priority even if a little late)

Providing two platforms in each direction at St. Pancras would at
least prevent the hanging around and allow trains from the two
northern branches to wait their 'slot' in a platform and allow
passengers to change to the underground if they wish. It also allows
slightly easier recovery from delays, as fast trains can pass stoppers
in the station, rather than having to wait until they are further out
from the center.

Jonathan Morton wrote:

While that may be correct, the failure to provide a 4-platform layout
(or at least 3 - see below) was a piece of penny-pinching which will
come back to haunt us. Remember that we were told that the provision
of the station box was an engineering masterpiece that could never be
done (or changed) in the future - it had to be done while St P was
being dug up, so it was a case of "right first time". But even with
this warning, no provision was made for island platforms. This
station cries out for islands - because station dwell time is going
to be longer than any other station on the line, so the ability to
signal the next train into the opposite face of the island (even if
both faces are not occupied simultaneously) would have been excellent
even in the northbound direction, and may prove essential to the
promised frequency. Southbound it would have enabled trains to arrive
simultaneously from Bedford and Peterborough. They got this right in
the 1930s at Baker Street, with two southbound platforms, one for
each branch (as it then was) of the Bakerloo.

Didn't that just move the bottleneck to Regents Park or Oxford Circus?

On Mon, 3 Dec 2007, Roland Perry wrote:

In message , at 15:03:14 on Mon, 3 Dec
2007, R.C. Payne remarked:

Why will the dwell times here be longer than other stations? I'd
have thought somewhere like City Thameslink or London Bridge would
have just as much excuse to have long dwell times, and wherever the
location of the voltage change also has a good reason to offer long
dwell times, what's so special about this station?

It's where two lines meet and merge. So you can only get the maximum
throughput if trains arrive from the two branches interleaved exactly
on time.

Is it? I thought they met and merged north of the station, and shared
a single 2 track approach from the north. If that is the case, then
they will have to interleave exactly regardless of whether the station
has 2 or 4 platforms.

The lines from the ECML aren't in place yet,

No, but the tunnels for them (the Canal Tunnels) are - they were built as
part of the CTRL works. AIUI.

but if they merge before the station it would make things worse.

I'm all but certain that there is not a four-track approach to the station
from the north.

I can't find maps or diagrams giving any details, though. Possibly people
who are more au fait with council planning department websites etc might
do.

tom

--
Basically, at any given time, most people in the world are wasting time.