Bank Station Part 2: The Upgrade Proposals

In part 1 of this article we looked at the need to upgrade Bank station to provide sufficient capacity for the number of people using it. We now look at the proposals put forward to achieve this.

TfL Map of new Tunnel

Map showing route of proposed new tunnel and the original proposed new ticket hall.

In November 2011, London Underground published their plans for the upgrade of Bank station and had the usual public consultation with an exhibition of the proposals. These did not produce any great surprises as the gist of the scheme was well known. Since then there has been a more interesting second consultation. Instead of basically asking people if they think the scheme is a good idea and giving people to comment on the fine detail, which was the case in the first consultation, three options are proposed. Of these three options two are presented in an equally positive light.

The Originally Proposed Scheme

The original scheme did not have a number of options. The idea was to acquire a property on King William Street and demolish it to provide a worksite for the deep level works and, when the job was complete, create two new entrances on King William Street itself.

Before we look at what this entails it is important to point out that an unusual, but not unique, feature at Bank is that the Northern line platforms are the “wrong way round”. At Bank they are roughly in a north-south alignment. This is means that the southbound platform is actually located west of the northbound platform which needs to be borne in mind when following details of the proposal.

Below ground the schemes are more or less identical and the proposals haven’t changed.

The critical features of the scheme are:

1) A new large wide concourse leading from the “Bank” end to the “Monument” end parallel to and between the Northern line platforms that can accommodate interchanging passengers.

Bank 3D model showing extent of new works. The parts in purple are the proposed new works. As can be seen they are quite substantial.

2) Diversion of the southbound Northern line for approximately 700m including a new six metre wide southbound platform that is both accessible by dedicated passageways from both ends and from the new wide concourse.

Artists impression of new southbound platform. This would be designed to the current standard for undergound platforms.The lack of Platform Edge Doors would appear to be a surprising omission.

3) Converting the existing southbound Northern line platform tunnel into an extension of the northbound platform and provide more and wider access points between the two tunnels to create the impression of one very wide northbound platform with regularly spaced pillars.

The upgraded northbound platform with a large circulating are where the southbound platform is currently. Because of the need to maintain the existing supports between the two current platform tunnels this is going to have strange feel as it will be unlike any other platform on the Underground.

4) Conversion of the now-defunct southbound running tunnel north of the old southbound platform into a passageway for direct access from the “Bank” end to the newly widened northbound platform.

The Original Worksite Proposal – Acquire 10 King William Street

To carry out the work it was going to be necessary to compulsorily purchase a suitable site and the office block at 10 King William street was proposed. From here an access shaft would be dug. This would not be infilled at the end but the site would be used to create a new station entrance and the access shaft used as a shaft for lifts. Escalators were quickly ruled out because the site is so restricted and there was no really viable route for an escalator shaft. Note that, despite the way the scheme was presented to the public, the new entrance was almost incidental and more a case of taking advantage of an opportunity rather than being a fundamental part of the scheme.

The building on the proposed worksite. One cannot imagine anyone will mourn its passing from an architectural standpoint. Note the narrow road and and narrow pavement. This is not ideal as a combined entrance and exit to a major construction site.

The Revised Proposals

In a rare moment of enlightenment, which is about as far away from the concept of PPP as you could imagine, London Underground then showed the plans to four leading construction groups to review the project’s design and construction methods and provide feedback. The idea is that one of the group will be selected to build the project but if any of the other construction groups contribute to the scheme by innovative suggestions then they will be suitably financially rewarded. You can see straightaway that such an approach is almost impossible to formalise in a contract and basically must rely on a level of trust and co-operation – the antithesis of PPP.

The main feedback from the construction firms was that the proposed working site was really constricted and this was going to cause not only construction problems but also Health and Safety issues. Indeed one could compare the size of the originally proposed site with that LU station enhancement site at Tottenham Court Road (the one by Centrepoint). The latter looks enormous, but is actually a really cramped site to work in. Use of space there has had to be carefully planned and allocated to avoid contractors getting in each others way. Furthermore, the originally-proposed worksite for the Bank Station Capacity Upgrade would have only had access from King William Street in the heart of the city. King William Street is not that wide for traffic and the pavements are also quite narrow. Any experienced major site manager or military planner will tell you that you really do not want the entrance and exit co-located and ideally the access and egress should be in from and out to different roads.

Fortunately the buildings surrounding 10 King William Street are, by City standards, neither particularly attractive, substantial or of major historical interest. The logical approach was thus to plan on making the working site bigger and encompass the entire block. Once that was done better opportunities became apparent for the customer entrance. For one thing an entrance on Cannon Street itself could now be provided. This would only be a short walk from the eponymous station and provide a new interchange opportunity.

It would seem that an almost inevitable consequence of this will be that a new secondary entrance and exit to serve the eastern end of the platforms at Cannon Street Underground station and located on the north side of Cannon Street will be suggested. One suspects that the stock LUL answer to this will be that the scheme justifies itself without such an entrance, and such an facility could still be provided in future if a valid case could be made for it.

Revised property acquisitions proposals in order to achieve a bigger worksite. An important objective is to have vehicle access to/from Cannon Street.

The revised plans open to consultation

The plans for an extended work area led to three proposals. They are as follows:

Option 1. Two Entrances on King William Street

This was the original scheme. It is unlikely to be the preferred option as it does not offer an entrance on Cannon Street.

Option 2. An entrance on King William Street and one on Cannon Street. Four Highspeed lifts would be installed

This may be the preferred choice if a lift-only solution is favoured.

Option 3. An entrance on King William Street and one on Cannon Street. Escalators would be installed

This would probably be the preferred choice if it is possible to build the escalator shaft.

In normal circumstances option 3 would probably be the favoured solution but installation of the escalator shaft would be technically challenging. Obviously there would still be limited capacity lifts for disabled access. However the escalators would be quite long due to the depth below ground of the Northern line at this point. After appreciating the disadvantages of very long escalators at Angel and Westminster (Jubilee line) there is a bit of a rethink concerning whether escalators should really always be the preferred solution just because their installation is possible, or whether there is a case for modern lifts in certain situations where both options are available.

Abchurch Lane

Not directly railway related, but another potential benefit of options 2 and 3, is that it would make the idea of pedestrianising Abchurch Lane more attractive and this is in fact part of the proposal. Potentially this narrow street could also be made wider, although it is not clear if this is one of the intentions. As well as providing a more pleasant ambience at the station entrance and removing a junction right outside it, it may also help provide a more pedestrian-friendly route from Cannon Street station to the heart of the City. A further benefit could be the opening up of the delightful but rather gloomy square that is Abchurch Yard set in front of the church of St. Mary Abchurch.

Abchurch Lane today. Surely a new Underground station entrance and a wider pedestrianised Abchurch Lane would be better than this?

Further Consultation

It is these new options which has lead to a second round of consultation. The closing date is July 2013. As a lot still has to be decided and work is not due to start before 2016 it seems likely that there will be a further round of consultation once more specific and detailed plans emerge.

A Bizarre Situation

This map (copyright TfL) shows the nine existing entrances to Bank station and the entrances to Mansion House, Cannon Street and Monument station. In future there will also be an entrance to Bank station in Walbrook Square, just south of the church in Walbrook, and maybe three more along the length of Abchurch Lane.

If Bank Station did have an entrance adjoining Abchurch lane on Cannon Street itself a curious set of choices would be present if one were to walk along Cannon Street. Near the western end would be Mansion House (District and Circle lines). Next, about 200m to the east in Walbrook Square, within sight of Cannon Street, would be Bank (Waterloo & City line entrance). There would then be Cannon Street Underground station itself (District and Circle lines). Around 100m further to the east of the mainline station would be Bank (Abchurch Lane entrance), particularly convenient for Northern line and probably the DLR. This entrance to Bank would probably be about the same distance from Cannon Street station as Walbrook Square. Finally at the eastern extremity, where Cannon Street meets King William Street, is Monument which is around 100m to the east of Abchurch Lane. That amounts to five distinct Underground station entrances of which three belong to one station (Bank & Monument) and between Walbrook Square (Bank & Monument) and Abchurch Lane (also Bank & Monument we have Cannon Street (District & Circle).

Construction and Disruption Issues.

The plans look wonderful but there is the classic problem of implementing them. The problem is quite simple. You cannot divert the Northern line southbound (remember the individual tunnels are “the wrong way round”) until the replacement platform is brought into service. Once that is done then you can divert the tunnel so that the trains can use the new platform. Unfortunately the most suitable place to rejoin the running tunnel at the north end of the station is close to where the running tunnels “roll over” each other.

Some readers may recall that, during the construction of the Victoria line, the Piccadilly line was famously diverted to a new platform at Finsbury Park and the line was closed for only half a day on a Sunday to achieve this using a “step-plate” junction. This is simply not going to happen in the case of Bank and both running tunnels will need to be closed to build the new junction. It is not yet known how long such a closure would last although weeks rather than months are being talked about.

A further unknown is that it may be possible to only close the northbound tunnel for a short period whilst critical work is done in the vicinity of it and then open it prior to completion of the southbound tunnel. This would of course only provide a very limited service as the trains could only return via the Charing Cross branch. At present it appears likely that for a limited time there would be through running southbound but no ability to stop at Bank station.

It is also not known what replacement services would be available. The necessary crossovers exist to enable a limited service to be run to Moorgate from Camden Town but south of Bank there is no opportunity to reverse trains north of Kennington. Whether or not two trains could provide a limited shuttle service by running two trains independently on both running lines between Kennington and London Bridge remains to be seen.

The plans then call for the (what will be) former running tunnel north of the (what will be) former southbound platform to be converted to a pedestrian subway. But now the problem is getting men and materials through the newly built areas of the station as well as having a work site Underground. So it remains to be seen if there will be a period when the southbound trains do not stop at Bank whilst reconstruction work is completed. Finally, with all subsurface work completed, the surface worksite can be turned into a new entrance.

Alternative Routes during closure

During closure people are inevitably going to have to walk for some of their journey. This, and the revised arrangements at surrounding stations, is going to have to be well planned.

Moorgate station (the next station north from Bank) is a manageable walk from Bank for most people. To reduce station congestion in the morning there would be the option of making the Northern line exit only at Moorgate.

On the south side the issue is more problematic. London Bridge (the bridge itself) is already very crowded with pedestrians at peak times and people are going to have to cross the river somehow. It may be possible, if needed, to shut a lane of traffic on the bridge so that there is more space for pedestrians. No doubt during this period there would be direct Northern line trains between Morden and Camden Town and a 30 train per hour service would be run, at least in peak hours, on the Charing Cross branch. However the difficulty remains that people who live south of the river on the Northern line will want to go to the City. Given the lack of spare capacity now, let alone in a few years time, it is difficult to see what alternative routes could be provided.

It must be emphasised at this point that nothing is finalised concerning how much closure is involved or indeed if it is definitely necessary. It could well be that one of the potential contractors come up with an engineering solution to reduce the severity of the closures and there maybe some options that London Underground could come up with that would substantially mitigate against any such closures that there may be.

Issues not addresssed

No doubt the station upgrade is a necessary and a good thing. However it is not a complete solution to all the problems at Bank and one needs to be aware of issues not addressed. It does nothing to deal with the number of passengers using the Central line platforms nor the extreme curvature – probably the worst at any Underground platform – and hence the enormous gap between the platform and the train there. The is no element of the plan that involves extracting any excess heat from the station and whilst the new entrance will be accessible to those with limited mobility, the plan does nothing for those entrances that are not.

The city is well used to massive building work being undertaken but this will probably be the most disruptive to the average city worker since London Bridge (the bridge itself) was rebuilt. Even those not directly affect will experience the knock-on effects as others have to replan their trip to work.

The gain will be great, but if not carefully managed, it will be very painful indeed.

Written by Pedantic of Purley