wrote:

How much re-plumbing and tunnelling would be needed to have the
southbound
platforms at Camden Town for the Bank branch and Charing Cross branch
rather
than calling at different platforms depending upon where they came
from, which
is not terribly useful.

No tunnelling if the lines were permanently paired, which is what a
split would entail. With the current service pattern, you'd need to
move the junction between the southbound Edgware/Barnet lines to be
north of the platforms, which however you did it (new junction
further north, new platforms further south, or most likely both) would
be insanely expensive.

U

In article . com,
wrote:

How much re-plumbing and tunnelling would be needed to have the
southbound
platforms at Camden Town for the Bank branch and Charing Cross branch
rather
than calling at different platforms depending upon where they came
from, which
is not terribly useful.

(I assume this would be done if they ever split the Northern Line into
two lines?)

Surely splitting the Northern Line would *remove* any benefits of
doing this? At the moment, each southbound platfrom sends trains down
either the Charing Cross, or the Bank branch. Were the line split, one
presumes that the Charing Cross branch would be permenently wed to one
of the Edgware and Barnet branches, and the Bank branch wedded to the
other one. The station would then automatically become one that
provided a cross-platform interchange between two north/south lines,
much like Finsbury Park. No tunnelling needed.

On May 11, 11:29 am, Sarah Brown
wrote:
Surely splitting the Northern Line would *remove* any benefits of
doing this?

Um, yes. Brain not in gear.

At the moment, each southbound platfrom sends trains down
either the Charing Cross, or the Bank branch. Were the line split, one
presumes that the Charing Cross branch would be permenently wed to one
of the Edgware and Barnet branches, and the Bank branch wedded to the
other one. The station would then automatically become one that
provided a cross-platform interchange between two north/south lines,
much like Finsbury Park. No tunnelling needed.

Wonder what they'd call the lines?

--
Abi

Wonder what they'd call the lines?

I'd suggest:
Northern (High Barnet - Kennington) - since it is much longer in the
north, then in the south
Eden (EDgware - MordEN)

Clive D. W. Feather wrote:

Camden Town's not cross-platform?

Actually only the northbound connection is level - the southbound
passageways involves stairs to connect to them. There's also much more
vertical overlap than you show. Making an attempt to edit your
artwork:

_____ _____
/ \______________________________/ \
NB Ew ____________ ____ ______ NB HB |
\_____/ _/ _| |_ \_ \_____/
_____ _/ _| |_ \_ _____
/ \__/ _| |_ \_____/ \
| SB Ew ____| |_______ SB HB |
\_____/ \_____/

While that is true of the middle corridor, is the corridor from southbound
to southbound at the southern end of the platforms not level?

In article , John Rowland
writes
Actually only the northbound connection is level - the southbound
passageways involves stairs to connect to them.

While that is true of the middle corridor, is the corridor from southbound
to southbound at the southern end of the platforms not level?

No. In fact, a vague memory says that it's more like an X - stairs on
all four sides.

On the southbound Edgware side the stairs are parallel to the track.

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is:

On Fri, 11 May 2007, wrote:

On May 11, 11:29 am, Sarah Brown
wrote:

Were the line split, one presumes that the Charing Cross branch would
be permenently wed to one of the Edgware and Barnet branches, and the
Bank branch wedded to the other one. The station would then
automatically become one that provided a cross-platform interchange
between two north/south lines, much like Finsbury Park. No tunnelling
needed.

Although the present passageway layout wouldn't be able to handle the
amount of interchange traffic that would result. This is one of the main
reasons why the line hasn't been split, and the reason LU have been
pushing their Camden redevelopment masterplan.

Wonder what they'd call the lines?

Charing Cross line and Bank line, perhaps. Dull, but consistent with what
we have now. Or perhaps something like the Northern Line for the CX bit,
and the City line for the Bank bit; you might then want to rename the W&C,
though. Hmm - Northern Line and Southern Line?

I like Alex's suggestion of the Eden line - although since it would run
through such places as Balham and Tooting, i fear it could lead to LU
being sued under the trade descriptions act!

tom

--
Vive la chimie, en particulier, et la connaissance en general. --
Herve This

On May 11, 7:58 am, "Clive D. W. Feather" c...@on-the-
train.demon.co.uk wrote:
In article . com, MIG
writes

Hmm. That map implies that the northbound City track passes *under* the
Victoria line, whereas this cut-away drawing:

http://www.geocities.com/Athens/Acro...9/lteusmod.jpg

Shows it passing *over* it. Anyone know which is right?

I'd misread this question before.

Having actually gone and looked on the way to work this morning, I can
report that the Northern (Bank) definitely climbs as it leaves Euston
for Camden Town while the Victoria Line is definitely heading downwards.
So the Northern goes over the Victoria (but all of them go *under* the
CX branch).



In the meantime, I was completely wrong about the old "Hampstead Tube"
entrance, which is on the corner of Drummond Street, whatever I said.
The CX line certainly does go under Drummond Street though, as we both
said.

On Fri, 11 May 2007, Clive D. W. Feather wrote:

In article , Tom
Anderson writes

Camden Town's not cross-platform?

Is it? I thought it has two close, but separate "sub-stations"?

Not exactly. There are separate bits for the Barnet and Edgware
branches, but the southbound platforms for both are sunk below the
northbound platforms, and there are level passageways connecting each
directional pair. Hang on, i'll have a crack at some ascii art:

Actually only the northbound connection is level - the southbound
passageways involves stairs to connect to them.

Ah, didn't realise that. Presumably, this is not such a huge deal, as
trains to both southern branches depart from each southbound platform, so
you have a same-platform interchange going south (provided a suitable
train is actually on its way). Going north, if you're on the wrong kind of
train, you will absolutely have to change platforms.

It's a shame that when Camden Town was built, it wasn't built as a proper
cross-platform interchange. I assume there are good reasons for it, but
it's still a shame.

tom

--
Throwin' Lyle's liquor away is like pickin' a fight with a meat packing
plant! -- Ray Smuckles

On Wed, 9 May 2007, Clive D. W. Feather wrote:

In article , Tom Anderson
writes

At Euston the two branches of the Northern Line are approximately at
right angles.

I was wondering, as i was sat on it this morning, whether it would be
possible to construct a connector between the Bank and CX branches
around about Euston, so that they could act as two arms of a loop, with
trains running Kennington - Bank - Euston - Charing Cross - Kennington
and vice versa. Based on what you say, perhaps not.

Not really, since it would have to miss Euston.

Not so! See my previous post with the ramble in it. Or not, if you prefer.

If so, though, it could be a useful way of focusing trains on the
termini-to-town section of the line, which i assume is the most heavily
loaded,

I'm not totally convinced it's enough busier, though there's a fair number
get off at KXSP northbound in the evening peak.

Facts, sir - pray do not trouble me with them!

either for extra trains during the peaks (which wouldn't need to negotiate
the delay-inducing Camden Town chicanery)

Why "delay-inducing"? The junctions are designed so that all possible
non-conflicting moves can be done simultaneously.

That's not enough to eliminate delay - you also have to be able to do
conflicting moves simultaneously .

It was my understanding that although the junction is graded, there's
still interference between the lines. Say you have a Charing Cross train
coming from Edgware, and a Charing Cross followed by a Bank coming from
Barnet. You can have the following sequence of events:

1. Edgware - CX arrives at platform
2. Barnet - CX arrives at platform
3. Barnet - Bank is approaching in tunnel behind
4. Edgware - CX departs
5. Barnet - CX is ready to depart, but has to wait for the Edgware - CX to
make it some way down the line before it can follow it, and is now delayed
6. Barnet - Bank is now stuck behind the waiting Barnet - CX, and is now
also delayed

So an Edgware - CX train has managed to delay a Barnet - Bank train.

It's the big-metal-rolly-thing analogue of head-of-line blocking in
network switches, if you've come across that (not that i'm implying you'd
sully your hands with such link-layer trivia ).

This wouldn't happen if there was enough space in the crossover tunnels to
hold a train, so that you could move it past the diverging junction,
allowing the train behind it to head off, before you were able to move it
over the converging junction. However, IIRC, posts passim established that
this was not the case for all the tunnels. It would also not happen if you
planned all arrivals so that this kind of conflict was avoided, but on a
line of this scale and frequency, in real-world conditions, this is
wishful thinking. Hence, the Northern line as we know it today.

It is entirely possible that i am seized of the incorrect extremity of the
stick here, but this is what i heard on the internets.

... it seems that it might be plausible.
[...]

I've now dug out more detailed material. The northbound CX branch under
Drummond Street is almost exactly in line with the southbound Bank branch
under Euston itself.

The Bank branch platforms are centered on Eversholt Street. The southbound is
under Doric Way and the northbound is 60m away, under the southern edge of
the main Euston station (almost mid-way between Doric Way and Grafton Place).
The CX platforms are at about 20 degrees to them. Their western end is under
Cardington Street and the eastern under under Euston, about 100m north of the
southern edge of the main building. The southbound Bank crosses under these
platforms about 40m from their western end at about 30 degrees to them; the
northbound crosses about 20m west of that end at about 45 degrees. The two
tunnels converge under the intersection of Coburg Street and Star Street.

The CX branch runs under Drummond Street to North Gower Street, then in a
curve radius 170m to meet Hampstead Road at the northern edge of Euston Road.
[The Victoria Line crosses Coburg Street 20m north of Euston Street and then
runs in a straight line to the point where Hampstead Road crosses the Euston
Road underpass.

Running east, the Bank branch southbound is straight for 220m from the
platforms to Ossulston Street, then curves for 80m to a point under the
middle of the northern edge of the British Library; the northbound leaves the
Euston Loop at the same point, crossing under the Victoria at Chalton Street,
40m south of the southbound. It then runs 90m east and crosses Midland Road
about 180m north of Euston Road; this is where the King's Cross Loop comes
off it. It's then 110m to the western end of the KXSP platforms, which is 20m
west of the east edge and 70m/50m north of the southern edge of St.Pancras
main building. The southbound platform and track is in a straight line to run
under Pentonville Road; the two platforms end about 80m west of York Road,
almost directly under the northbound Piccadilly. The northbound platform is
about 20m south of the southbound; the two tunnels converge about 160m east
of the station.

Superb info, thanks!

tom

--
Throwin' Lyle's liquor away is like pickin' a fight with a meat packing
plant! -- Ray Smuckles