Narrow island platforms

[chrisvandenkieboom]

Was there a reason the C&SLR liked underground narrow (and with that I mean dangerously narrow) island platforms? They are still there at Clapham Common, Clapham North and the closed KWS, but they also were at LBG, Angel and Euston (Bank Branch), of which Clapham Common, Angel & Euston were C&SLR terminuses. Was this part of this decision, or were the narrow islands chosen as a cost savings measure; or would it have been more convenient for passengers to have 2 tracks closely together?

[trc666]

The C&SLR when constructed followed the route of what is now the A3. The tunnels were bored beneath roads to avoid the payment of easements to property owners, so I would imagine that this would be a factor in the island platforms being very narrow.

[slugabed]

I seem to remember having read that the original C&SLR station at Stockwell also had an island platform....the crossover to the North of the current Northern Line platforms being in the larger station tunnel.
I don't think London Bridge ever had an island platform....am I wrong?
I suspect that being termini was also a factor in the design,but that wouldn't explain Clapham North...

[chrisvandenkieboom]

- Platform 3, the northbound City branch, was diverted to provide a cross-platform interchange with the northbound platform of the new Victoria line. As the two City Branch platforms were of an island formation, the track bed serving the old platform 3 was filled in to create an extra wide City branch southbound platform (platform 4 in the diagram above - renamed platform 6 after the arrival of the Victoria Line) relieving the dangerous overcrowding that had been occurring on the small island platform (similar works have taken place at Angel and London Bridge).

-http://www.abandonedstations.org.uk/Euston_station.html
2 islands nuked in the 1960s and 1 in the 1990s. Will 2 be nuked in the 2010s? We can only guess...

The crossover just north of the existing Stockwell station is the site of the original island platform 1890 Stockwell station,
opened as the southern terminus of the City & South London Railway. Curious that both the original terminii should have
been re-sited (King William Street being the northern terminus).

-http://www.abandonedstations.org.uk/Stockwell_station.html
apparently, yes. Also; , according to the website it was the opening brochure but it was Stockwell.

The C&SLR had to stay under the roads, indeed.

[slugabed]

Sorry to be pedantic,but I remember London Bridge in the 70s and,as I recall it had "Morden Extension" tiling and two separate platform tunnels.So if it was ever an island,it was before the reconstruction works of the 20s...that would be interesting to learn.Perhaps there is a photo?
Reading the quote you give shows its ambiguity.
When the Jubilee line was extended in the 90s,a new platform tunnel was built at London Bridge,and one of the old platform tunnels used as the circulating area between the new and old platform tunnels.
In a sense this was similar to the work at Angel (also in the 90s),in that a new platform tunnel was built parallel to the old,and the space thus freed-up used to make the platforms less cramped,but the layouts of the stations,both before and after,were very different.
As always,I am ready to be corrected (not for the first time).

[Ben]

Only speculation, but I suspect the island platforms would have been marginally wider before the Northern line was reconstructed in the 1920s, reason being that the C&SLR stock was narrower than the Standard Stock. C&SLR would be the man on here to ask though.
On top of that the loadings were small compared to what eventually Angel and Euston suffered before reconstruction.

London Bridge wasn't an island, it was two separate platform tunnels, one of which became a circulating passage with a new platform tunnel bored. Similar to what might happen at Bank in the future perhaps.

[phillw48]

The Present London Bridge station was opened when the C&SL was extended northwards to Moorgate in 1900. When it was first built the C&SL used a smaller bore tube than what became the LT standard of 12 feet, IIRC it was about 10' 9". This meant that when the tubes were enlarged to 12 foot in the 1920's the platforms had to be narrowed slightly as the station tunnels were of brick arch construction and could not be enlarged.

[Deleted]

London Bridge [Northern] was very similar to Bank... an island platform separated by narrow archways between platforms...

King William Street had on opening, one track and two platforms... latterly replaced to an island platform, rather narrow mind, to increase operational flexibility!

[Deleted]

Part of the original NB platform was filled in for a stairwell to be dropped in... the ends of the platform were hoarded off, and I suspect these parts are used for storage until they obviously join up with the original alignment...

[Deleted]

Of the C&SLR stations, Euston, Angel, (King William Street got an island platform in 1895), Stockwell, Clapham North and Clapham Common were built with island platforms. Kings' Cross, City Road, Old Street, Moorgate, London Bridge and Borough were built with separate station tunnels.

Here's Angel before re-building in 1990:

Original Angel by DH73, on Flickr

[Ben]

Could well be, RT. According to ragajohn www.abandonedstations.org.uk/RaggaJohn.html#london%20bridge
there was also some sort of siding/crossover to the south of the station aswell.

[chrisvandenkieboom]

So all C&SLR stations with islands but Clapham North had narrow islands... a clear lack of planning, as they are quite dangerous. How expensive would a reconstruction be of both?

[phillw48]

Dec 27, 2011 10:11:43 GMT chrisvandenkieboom said:

So all C&SLR stations with islands but Clapham North had narrow islands... a clear lack of planning, as they are quite dangerous. How expensive would a reconstruction be of both?

Not a case of lack of planning, by the standards of the day when they were built (1890) it was quite acceptable. The stations were also fully staffed throughout the working day.

[chrisvandenkieboom]

True. The lack of planning nowadays would be even worse, methinks.

[Deleted]

I recall that there was quite a bit of apprehension at the time about the loss of the Northern line crossover at London Bridge, because it had proved useful as an emergency reversing facility, but converting what was the southbound platform tunnel into a centre concourse provided the only way of introducing any sort of sensible interchange link with the new JLE platforms. It also enabled a reasonable escalator and stairs link to be provided between the Northern line platforms and the new Borough High Street ticket hall. A Borough High Street ticket hall was created because it made London Bridge Underground station more accessible to its catchment area and - usefully - double-ended the station.

If you want to see an example of the problems that closely-spaced platform tunnels can cause, then look at the staircase link that was built between the Northern line platforms at Bank and the DLR platforms below. That was a very late addition to the layout at Bank and was a very, very tight and tricky piece of engineering! It was, though, the only addition to the station layout that it was physically possible to do at the time, given the Parliamentary Powers that were available.

I do wish those who are working on the current Bank station enlargement project every success - it is a very difficult location!

[chrisvandenkieboom]

Aren't both ends of Northern SB @ Bank escalators? That explains a lot, I guess.

[Deleted]

At Bank the two Northern line platform tunnels are close together. At the northern end, each platform has a staircase that leads up to a concourse - all pretty cramped and often very crowded. At the southern end, the two platforms lead into a small concourse and then to a bank of two escalators that lead up to the subway link to Monument. The direct staircase link from between the two Northern line platforms down to the DLR at least takes some of the pedestrian traffic that is interchanging from Northern to DLR. However, given the way in which traffic has developed, a large-scale enlargement of the station is sorely needed.

[chrisvandenkieboom]

I'm supposed to know that, since I have walked through Bank off-peak this summer. Interchanging traffic should never, ever go via a platform; so when Bank is going to be reconstructed, the current southbound seems perfect for a walkway link, while the new southbound could be extra wide. Wonder what they're going to do with the northbound... Enlarge it (hard), or leave it this way but more step-free... What direction is most Northern traffic at Bank usually?

[norbitonflyer]

Dec 27, 2011 14:25:20 GMT @rhubarbrhubarb said:

If you want to see an example of the problems that closely-spaced platform tunnels can cause, then look at the staircase link that was built between the Northern line platforms at Bank and the DLR platforms below.

The recent closure at TCR was, so I understand, to squeeze a little more space between the platforms to get a lift shaft in.

[Deleted]

Dec 27, 2011 10:11:43 GMT chrisvandenkieboom said:

So all C&SLR stations with islands but Clapham North had narrow islands... a clear lack of planning, as they are quite dangerous. How expensive would a reconstruction be of both?

A bit of a daft statement.

For the 1890s, and expected patronage, the line was reasonably well designed for it's purpose (especially as it was originally designed for cable haulage and not electrical traction). No one could have foreseen based on knowledge at the time how popular and extended the railway would become in it's 121 year history.

More expensive elaborate designs at the time could have resulted in the C&SLR never existing.

[chrisvandenkieboom]

Tubes were quite expensive; all current tubes did take a lot of time to be constructed, thanks to the financial problem.

[Deleted]

I am just speculating, but it seems that (with 2 exceptions), all original C&SLR stations had single-tunnel island platforms unless they were interchange stations. So I reckon that island platforms were built because they were cheaper and interchange stations didn't have them because of the large number of passengers that use them.

[phillw48]

Dec 29, 2011 9:16:55 GMT @videomaniac29 said:

I am just speculating, but it seems that (with 2 exceptions), all original C&SLR stations had single-tunnel island platforms unless they were interchange stations. So I reckon that island platforms were built because they were cheaper and interchange stations didn't have them because of the large number of passengers that use them.

When the line was built there were no interchange stations, the line was completely isolated. The line was confined wherever possible to the streets above and in some cases there was insufficient width for both lines and a platform so they resorted to two station tunnels one above the other and slightly offset. On the approach to the King William Street terminus the tubes themselves were placed one above the other because the road above was so narrow.

[Deleted]

I was referring to interchange with mainline railways.

[phillw48]

Dec 29, 2011 12:23:07 GMT @videomaniac29 said:

I was referring to interchange with mainline railways.

When first built the C&SLR did not connect to any main line station. It ran from Stockwell via The Oval, Kennington, Elephant & Castle and Borough and then terminated at King William Street. London Bridge Station was not opened until 1900 when the line was extended north to Moorgate.

[SE13]

I was reading something about the Glasgow subway and it's island platforms, which then linked to London, and the reasons plus street diagrams of why some were islands. Only thing is, I'll be damned if I know where I read it, or what computer I was on........ Should I retrace it, I'll post it here, but it appeared that there wasn't an inch of unused road space, nor an inch borrowed.

It also ties in nicely with something M drew a while ago referring to crossing tunnels to take some sharpness out of the bends - The whole history of which, given the dates, is positively illuminating.

[Deleted]

Dec 29, 2011 15:57:39 GMT phillw48 said:

Dec 29, 2011 12:23:07 GMT @videomaniac29 said:

I was referring to interchange with mainline railways.

When first built the C&SLR did not connect to any main line station. It ran from Stockwell via The Oval, Kennington, Elephant & Castle and Borough and then terminated at King William Street. London Bridge Station was not opened until 1900 when the line was extended north to Moorgate.

I know, but I am talking about when the C&SLR ran from Euston to Clapham Common (which was in 1900).
With a couple of exceptions (eg: City Road, Borough), it seems that at that time almost all of the non-interchange stations had island platforms and all of the interchange stations did not.

[mikebuzz]

What other island platform stations in tunnel were (/are) there, other than on the old C&SLR route and the Glasgow Underground?

[Deleted]

Dec 29, 2011 20:42:47 GMT mikebuzz said:

What other island platform stations in tunnel were (/are) there, other than on the old C&SLR route and the Glasgow Underground?

Liverpool Central (originally Mersey Railway, now Merseyrail Northern Line).

[Geoffram]

mikebuzz has raised a very interesting point (or, at least, I think so). The CSLR seems to be the only deep-level tube to have gone in for underground island platforms. I say underground, because if you look at the (then) Bakerloo extension to Stanmore, most of the stations in the open air past Finchley Road were island platforms, and yet Swiss Cottage and St. John's Wood weren't. In fact, the platforms on these two stations (like at Highgate, which is roughly the same vintage) are quite far apart so that the escalators could come down between them. By the 1930s, it seems the Underground could be built without the wayleave restriction of routing them under streets as had been the case twenty-five years beforehand (does anybody know exactly when this rule was relaxed, by the way? Was an Act of Parliament involved, or was it just custom and practice?). In any case, north of Finchley Road was really just a re-arrangement of four existing Metropolitan tracks andt it must have just seemed easier to put one platform between what became the up and down Bakerloos.
But the CSLR remains a bit of a mystery. If you take King William Street out of the equation (because it was a special case), I have a theory that works except for one station. The original Parliamentary Bill specified that both the lines would be in twin tunnels, but it didn't specify that all the stations had to be. Borough, Elephant & Castle, Kennington and Oval were all built with separate platforms. However, the original terminus, Stockwell was an island platform, which - if you look at the original Engineering diagrams - just fitted inside the road at the point. Indeed, the twin tunnels broke into one single tunnel just before the spur to the Depot at Stockwell and the scissors crossover just north of the site of the original station. So maybe here's a good reason why Stockwell was an island platform: it was a terminus with a scissors crossover attached to it. Ten years later, two extensions pushed the line in 1900 both north and south: to London Bridge, Bank and Moorgate which were all single platforms, and Clapham North and Clapham Common which were both island platforms. Like Stockwell, there is a sort of logic in that Clapham Common was a terminus with a scissors crossover within the single tunnel. OK, this logic doesn't quite work for the intermediate station, Clapham North, and that remains my only exception to the rule. To the north, at the time of completing Moorgate station, plans were already afoot to extend to Angel, so it was only ever going to be a temporary terminus and thus there were single crossovers both to the north and the south of the station. Neither Old Street nor City Road were ever intended to be termini either and the platforms there were in single tunnels. Angel was an odd place to site the terminus of the line, but the Metropolitan Railway objected to the CSLR reaching King's Cross on the grounds it might interfere with Moorgate-King's Cross traffic and so it stayed a terminus for six years and was constructed as an island platform. It's worth noting that by 1901, the Central London Railway had opened, and even though it had two underground termini at the time of opening, Shepherd's Bush and Bank, none of the stations on the line were island platforms. And although the three tubes that became the Yerkes tubes were still at the planning stage, none of them had any island platforms. When the final extension of the CSLR came in 1907, King's Cross was in separate tunnels, while the terminus at Euston was an island platform. If I'm right, both the CCE&HR and the CSLR opened in the same year and both were constructed under Euston station itself. This all leads me to believe that limitations of space above the line was not the deciding factor in the construction of CSLR Island platforms.