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Old May 23rd, 2011, 05:30 PM   #3341
lemmo
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This graphic of Bank indicates that DLR has a clear run towards Moorgate



The Crossrail website has a cross-section of Moorgate that shows the Northern lines tunnels below the level of the escalator, but it is difficult to tell where the GN&City lines run.

http://www.crossrail.co.uk/route/sta...design#content



Do the Crossrail escalators indeed block the GN&City? If so, what was the rationale behind that?

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Old May 23rd, 2011, 10:39 PM   #3342
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Trouble with the GNCR is short platforms, so to make any extension work worthwhile you'd need to extend the platforms too (= £££). In 2018 the ECML will be linked to Thameslink allowing 12 car through trains to the Southern Region, reducing yet further the potential use of the GNCR as a cross-London route (I guess the neatest and shortest extension would be to Cannon Street).
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Old May 23rd, 2011, 11:37 PM   #3343
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Thanks Tubeman, but the question is whether extending the GN&C is even possible now, if there is a Crossrail escalator in the way.

Extending to Cannon St, so you mean a sub-surface terminus?
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Old May 24th, 2011, 08:51 PM   #3344
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Quote:
Originally Posted by lemmo View Post
Thanks Tubeman, but the question is whether extending the GN&C is even possible now, if there is a Crossrail escalator in the way.

Extending to Cannon St, so you mean a sub-surface terminus?
No, I mean as in GNCR being extended south from Moorgate to Cannon Street and rising there to take over the Cannon Street branch and onwards to the Southern region. I'd probably close Cannon St altogether (including the District Line station) and have platforms on the extension below Bank, i.e. Moorgate - Bank - London Bridge.

Probably the shortest bit of tunnel to achieve a new 'Crossrail' service, but the problem I noted about GNCR platform length would need to be addressed to make the venture worthwhile.

I'd always thought the GNCR was stacked below the Northern Line between Moorgate and Old Street actually, hence the GNCR may be deep enough to evade Crossrail 1... but the Crossrail 3D diagram contradicts this
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Old May 24th, 2011, 09:20 PM   #3345
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Judging by the corridors at Old Street, the GNCR lines are above the Northern Line.
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Old May 25th, 2011, 12:09 AM   #3346
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Being above the Northern line is the biggest GCNR problem for extensions - the Lothbury extension was possible (and would have been linked in with Bank eventually), but any further and the central line would be in the way.
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Old May 25th, 2011, 08:47 AM   #3347
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This pic shows that the GN&C platforms lie above the Northern platforms



If you combine that with the cross-section on the Crossrail website, it seems that the escalators would lie in front of a GN&C extension.


However, I thought that the GN&C had overrun tunnels that extended a distance down Lothbury, where the original Greathead shield is still buried when they stopped boring the new new tube. This doesn't appear on the Crossrail diagram.

Tubeman, interesting idea, but how would you get the GN&C lines to the surface and onto the viaduct around the skyscraper-laden Cannon St area?
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Old May 25th, 2011, 08:25 PM   #3348
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[QUOTE=lemmo;78387898]This pic shows that the GN&C platforms lie above the Northern platforms



Yes I already noted that... Just always had it in my head that the earlier Northern was above the later GNCR... clearly wrong though!

Quote:
Originally Posted by lemmo View Post
Tubeman, interesting idea, but how would you get the GN&C lines to the surface and onto the viaduct around the skyscraper-laden Cannon St area?
The buffer stops at Cannon Street are only slightly above street level... Bear in mind The City is a hill (hence it being chosen as the location for a city), and streets run quite steeply down to the river. Therefore, if Cannon Street station was done away with in favour with a new deep level station under Bank en route to Moorgate, then I'm sure there's be sufficient distance between the river bridge and the north end of the station footprint to sink ramps down below District Line level, as the ground is rising steeply.

Anyway, sorry not really Crossrail!
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Old May 26th, 2011, 12:35 PM   #3349
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my thoughts were that the DLR maybe could be joined to the GNCR and perhaps terminate at Finsbury Park.

The reason is that the DLR can cope with steep gradients admirably (as proven in quite a few places). I was wondering whether it'd be able to cope with a climb from the deepest parts of Bank to the highest parts of Moorgate! Presumably the tunnels would have to wrap around the Northern Line tunnels.

An even more radical solution might be to utilise the fact that the Northern Line tunnels themselves are stacked north of Bank, and therefore might it be possible to somehow have a north-north Northern Line/DLR cross-platform interchange at Moorgate and south-south Northern Line/DLR cross-platform interchange at Bank.
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Old May 26th, 2011, 06:52 PM   #3350
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Quote:
Originally Posted by Jang0 View Post
my thoughts were that the DLR maybe could be joined to the GNCR and perhaps terminate at Finsbury Park.

The reason is that the DLR can cope with steep gradients admirably (as proven in quite a few places). I was wondering whether it'd be able to cope with a climb from the deepest parts of Bank to the highest parts of Moorgate! Presumably the tunnels would have to wrap around the Northern Line tunnels.

An even more radical solution might be to utilise the fact that the Northern Line tunnels themselves are stacked north of Bank, and therefore might it be possible to somehow have a north-north Northern Line/DLR cross-platform interchange at Moorgate and south-south Northern Line/DLR cross-platform interchange at Bank.
That's an interesting new idea, and something I've not heard before.

Additionally, I posted this recently in another forum and I thought it might be relevant:

Quote:
"London's Lost Tube Schemes" regarding the plan in 1902

The GN&CR had a bill of their own, for a 240 yard extension south from Moorgate to Lothbury. <snip> The station at Lothbury would be entirely underground, with staircases to each corner of the road junction. <snip> Had a full-length train ever used the extension it would have been arriving at Lothbury before it had fully departed Moorgate, since the running tunnel between the two stations was to be shorter than the platform tunnels. <snip> It was explained that the line could not be brought any further south because the C&SLR tunnels were placed one above the other in Prince's Street, due to the narrowness of that road. The GN&CR, being above the other at Moorgate, would have great difficulty placing its two large tunnels above one another, and above the C&SLR, <snip>
Interestingly, as part of the new extension works, a new station was to be built between Drayton Park and Essex Road, called Highbury (today's Highbury & Islington). So I guess more work than just installing the tunnelling shield was completed after all.

The book also states that the the MR opposed the bill, as they wouldn't have room for an express line under their existing lines (the GN&CR being just 11m underneath them), just as the MDR was planning to build.

Despite permission being granted, the GN&CR simply didn't have the funding, so it was abandoned very quickly.

The plan was revived by them again in 1907, but they still had no money, so it wasn't until the line was taken over by the MR that a new plan came about in 1913. First to connect the southbound GN&CR running tunnel to the SSL under Finsbury Circus, and when that plan failed, to extend to Lothbury as previosuly planned, and then:
Quote:
"London's Lost Tube Schemes"

However, a further extension would prolong the line by another 250 years to join the eastern end of the W&CR station tunnels, just beyond the platforms at City station. The new southbound tunnel would cut through the existing eastbound overrun tunnel, which continued beyond the platform in a straight line. <snip> Expanding th etunnels of the W&CR was not proposed. Instead, the line to Lothbury would be built to match the existing GN&CR, but south of that station the new tunnels would have a diameter of 12 feet.
There's a lot more, but you get the idea.
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Old July 1st, 2011, 08:54 AM   #3351
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http://www.theconstructionindex.co.u...poil-recycling

Spoil recycling news. Re-instatement of a rail link in Northfleet, Kent for this.
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Old July 1st, 2011, 06:11 PM   #3352
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I've drawn the two proposed crossrail lines from the 1974 London Rail Study report.



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Old July 1st, 2011, 07:02 PM   #3353
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For those who find those maps hard to read:

Brown line: GWML - Paddington - Marble Arch - Bond Street/Oxford Circus - Leicester Square/Covent Garden - Holborn/Chancery Lane - Moorgate/Liverpool Street - Stratford - ...

Red line: ... - Victoria - Green Park/Piccadilly Circus - Leicester Square/Covent Garden - Ludgate Circus - Cannon Street/Monument - London Bridge - ...

I must say that I like the hub station being Leicester Square/Covent Garden, but then again that could be a leisure traveller's bias.
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Old July 1st, 2011, 10:20 PM   #3354
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If only there had been no 70's oil crises at least one of these might have been built by the 80's
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Old July 2nd, 2011, 10:14 AM   #3355
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Quote:
If only there had been no 70's oil crises at least one of these might have been built by the 80's
The upcoming 'peak oil' crisis is exactly the reason why these need to be built now.

Anyway my point above about Moorgate is that the Crossrail design at Moorgate means that any extension to the GN&City will now require a new alignment and platform tunnels, and looking at the cross-section on the Crossrail site, there may well not be any space now to do that. I'd appreciate more info if anyone has it.



DLR has 6m diameter tunnels, GN&City has 16', so that's not an option unless you rebore. Plus, one of the values of the GN&City is that it is standard gauge and has grade-separated junctions to the GN mainline, so could link existing surface lines.

Connecting the Waterloo & City to the GN&City is not an option as you'd have to completely rebuild around Bank.

So, Crossail as a solution to London's transport problems, appears to have restricted options to provide a further north-south solution in the future
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Old July 2nd, 2011, 11:40 AM   #3356
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Quote:
Originally Posted by lemmo View Post
So, Crossail as a solution to London's transport problems, appears to have restricted options to provide a further north-south solution in the future
I don't think it's quite that bleak. We're getting hung-up over the existing Moorgate platforms for the GN&C, but these platforms are far too short for the 12-coach trains a proper "Thameslink 2" route would need to support anyway, so it's a moot point: the platform tunnels would need to be rebuilt regardless.

However, this means it's as easy to relocate the Moorgate station platforms as it is to rebore them: most planners may prefer to do this in order to retain existing services while the conversion work is ongoing, thus reducing disruption to a minimum.

Modern EMUs can cope with some pretty steep gradients—it's the curves that cause the headaches as coaches have grown longer over the last century or so—so diving through the current Cannon Street site and deep under Bank is certainly viable. As the City is also known as the "Square Mile", there's a lot to be said for not bothering with a Moorgate stop at all, and simply joining the new tunnel to the existing GN&C route further up instead.

This leaves only the remaining GN&C stations to be extended, but one of these is on the surface and thus easier to deal with. (Adding a turnback facility here would be useful in reducing the demand to reopen the closed station on the Piccadilly Line to serve the football stadium. A bay platform at an extended station here will certainly help with passenger flows during popular matches. As will through services to south London.)

Rather than reboring the existing station tunnels, I'd recommend adopting the "Angel" / "London Bridge" Northern Line solution of building new platform tunnels outside the existing ones, with the latter then converted into additional circulation space. The circulation space at these stations will need improving to cope with the numbers anyway, so this solution offers two bangs for the buck: "free" circulation space improvement, plus longer platform tunnels constructed while existing services are still running. You'd still have to close the line for a while, but it would be for a much shorter period than the alternative.

The elephant in the room is the Monument/Bank complex. Building a new mainline station beneath it all means having to thread umpteen new escalators and corridors through the entire complex: not easy, or cheap. And it only adds to an already very complex station. This site could really do with a clean slate approach—a grand "masterplan" project all to itself as it's a royal mess of a station at present.

I believe it would be better (and far, far cheaper) to just route the new line around it instead, with the interchange at Liverpool Street. As Crossrail 1 will be joining Liverpool Street with Moorgate, a station here will also benefit from links with the Northern (City branch) Line, as well as the Central. The trick will be getting the line from the Cannon Street area to Liverpool Street as this requires threading it under—or just over, if road levels and gradients permit—the District and Northern Line tunnels.

The only interchanges you lose with this option are minor: the Waterloo & City—just change at London Bridge—and the DLR. Crossrail 1 will already offer much quicker, and more convenient, access to Canary Wharf anyway at Liverpool Street, so I doubt direct DLR access will be missed.

Cannon Street will either need to become a Blackfriars-style river-spanning station—which would involve a South Bank entrance located very close to London Bridge—or it will need to be closed completely.

I favour the latter: the station's sole purpose was to serve the City and it sees very little footfall outside City working hours. A river-spanning station would place the "City"-end entrance much further away than the present site as the line would need room to dive underground, thus reducing its usefulness.

Furthermore, the City isn't nicknamed "the Square Mile" without good reason: with City Thameslink and Farringdon / Barbican at the western/north-western boundary, a new interchange at Liverpool Street / Moorgate will suffice for the other, with easy interchanges (Crossrail 1, Central, Metropolitan, H&C, Circle) available to other locations within the Square Mile.

Cannon Street's District station will likely need to be closed and / or resited to enable the new tunnel, but this would be done as part of the terminus' conversion into a tunnel portal anyway. Keeping a station here on the SSL has some logic to it, but Monument is already pretty close by, so it's by no means all that necessary; closure could therefore be justified. This would also speed up journey times on the Circle and District services, thus benefiting services on those lines too.

I hereby rest my case.
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Old July 2nd, 2011, 02:07 PM   #3357
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Quote:
Originally Posted by stimarco View Post
I don't think it's quite that bleak. We're getting hung-up over the existing Moorgate platforms for the GN&C, but these platforms are far too short for the 12-coach trains a proper "Thameslink 2" route would need to support anyway, so it's a moot point: the platform tunnels would need to be rebuilt regardless.
I don't think it's that bleak either...as far as I can tell, moving the escalator shaft in question eastwards by a few metres would enable it to clear the GN&C alignment easily...which is why it's all the more incredulous that they put it where they did.

...or far more annoyance is the circulating area that looks like it will preclude knocking through the bays and extending the SSL across Finsbury Circus under all that nice soft grass to Liverpool St.

As for the whole extending the platforms malarky...I still think the GN&C will be fine as a tube route. Build a new, faster tunnel to the correct gauge for OHLE beneath it that you can route to more useful stations (Finsbury,Dalston,Liverpool St/Lothbury-Cannon St/London Bridge,Surrey Quays Junction).
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Old July 2nd, 2011, 06:26 PM   #3358
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Quote:
Originally Posted by mr_jrt View Post
As for the whole extending the platforms malarky...I still think the GN&C will be fine as a tube route. Build a new, faster tunnel to the correct gauge for OHLE beneath it that you can route to more useful stations (Finsbury,Dalston,Liverpool St/Lothbury-Cannon St/London Bridge,Surrey Quays Junction).
I think it's the ghosts of the Moorgate crash that will prevent TfL ever reusing a mainline-gauge tunnel for Tube-gauge stock again if it can possibly avoid it.

But I'm not sure anything longer than a six-car Tube train (assuming one of the newer stock types) would actually fit into the existing platforms anyway, which limits the scope for any extension of the line through the rest of London. They really are quite short. SDO might let you get away with 7-car trains, but it's far from ideal, and these trains would be isolated from the rest of the Tube network too, so maintenance would be a bugger. The route really is best served by mainline gauge stock, given the way it's been laid out.

You have to extend the line to the south—not just the north—to make it viable as a tube line, as that's kind of the point of Tube lines (and no south London taxpayer is every going to agree to yet another north-of-the-river Tube extension anyway). If you're going to go to that kind of expense, you may as well extend it as a mainline route.

Besides, what would you extend the line to? The W&C isn't really a goer: it's just too awkward to reach from Moorgate, even without the Crossrail works. And there's a big question mark over how well the existing stations would cope with the greater passenger numbers.
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Old July 2nd, 2011, 11:24 PM   #3359
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Quote:
Originally Posted by stimarco View Post
I think it's the ghosts of the Moorgate crash that will prevent TfL ever reusing a mainline-gauge tunnel for Tube-gauge stock again if it can possibly avoid it.

But I'm not sure anything longer than a six-car Tube train (assuming one of the newer stock types) would actually fit into the existing platforms anyway, which limits the scope for any extension of the line through the rest of London. They really are quite short. SDO might let you get away with 7-car trains, but it's far from ideal, and these trains would be isolated from the rest of the Tube network too, so maintenance would be a bugger. The route really is best served by mainline gauge stock, given the way it's been laid out.

You have to extend the line to the south—not just the north—to make it viable as a tube line, as that's kind of the point of Tube lines (and no south London taxpayer is every going to agree to yet another north-of-the-river Tube extension anyway). If you're going to go to that kind of expense, you may as well extend it as a mainline route.

Besides, what would you extend the line to? The W&C isn't really a goer: it's just too awkward to reach from Moorgate, even without the Crossrail works. And there's a big question mark over how well the existing stations would cope with the greater passenger numbers.
Had TPTW (the powers that were ) not both proposed to link the GN&C & the W&C as well as put bills before parliament to authorise them to do just that, I might agree it's not feasible...but they did, so I contend that's it's just too expensive, but quite possible to do so.

...as for the tunnel diameters...given the need for airflow and walkways, the DLR's tunnels are 17' vs. the GN&C's 16', and vs. the tube's 12' (and the JLE's tunnels are 14.3'). I don't think it's an issue any more TBH.
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Old July 3rd, 2011, 09:00 AM   #3360
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Quote:
moving the escalator shaft in question eastwards by a few metres would enable it to clear the GN&C alignment easily...which is why it's all the more incredulous that they put it where they did
They'd need have needed to move it a few metres upwards. I think the single tunnel shown at that point in the cross-section is a pedestrian walkway.
Quote:
far more annoyance is the circulating area that looks like it will preclude knocking through the bays and extending the SSL across Finsbury Circus under all that nice soft grass to Liverpool St
Difficult to see what value this would add, apart from future-proofing, but you'd still have to dig under buildings/roads around Finsbury Circus. Of more annoyance for me is that now you cannot extend the DLR into the empty platforms at Moorgate. Any DLR extension to Barbican/Farringdon would now have to rise at the west end of Moorgate station.

What all this suggests to me is that there is precious little strategic overview of rail infrastructure across London, and very erratic safeguarding.

The cutaway diagram of Bank above indicates that you could extend the W&C but you'd have to drop a fair way below DLR.
Quote:
Had TPTW (the powers that were ) not both proposed to link the GN&C & the W&C as well as put bills before parliament to authorise them to do just that, I might agree it's not feasible...but they did, so I contend that's it's just too expensive, but quite possible to do so
I don't know what TPTW is, but I'd be interested in seeing bills/plans/costs. As far as I know this has never really progressed beyond the proposal stage.

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