This is the third blog in a series of three on Crossrail, the major new rail tunnel running under London. The first and second entries were written to set the scene for this entry, which focuses on solving the major problem of Crossrail - two eastern branches - with the Swanlink proposal.
Low frequency branches
The big problem with Crossrail is not that there are two eastern branches, but that the dividing point of those branches is so close to central London. This means that of the 24tph serving the central section from Paddington to Whitechapel, only half can continue to Stratford and half to Canary Wharf. However, there is clearly demand at both Stratford and Canary Wharf for all 24tph to go there.
The official response to this appears to be threefold. Firstly, that the capacity of each train is large, secondly that the trains can be lengthened by 2 carriages, and thirdly to design the signalling for future running of 30tph. The first and second points are fine, but miss the fact that trains of similar size already run via Stratford and are already full when running at a higher frequency. The third point would still only provide 15tph down each branch, but more importantly removes resilience from the network meaning worse recovery from incidents.
So, I've looked at what is needed to fix the problem, making the Crossrail investment dramatically more effective to the whole of London.
This proposal is designed to solve multiple problems with London's rail network in a single hit. As such, it should have a good rate of return.
Clearly, the only way to solve the eastern branch problem is to run a full 24tph service on each branch, to at least Stratford and Canary Wharf. Simple logic therefore requires some new tunnelling from the Stepney Green junction to provide the necessary tracks. But the question is where should they go?
At this point, I switch to the recent London & South East RUS, which identifies capacity shortfalls in the railways around London:
With respect to longer distance services the RUS therefore notes that a significant peak capacity gap may arise, with a forecast shortfall in capacity for some 7,000 passengers in the busiest peak hour; this figure includes capacity required on today’s already overcrowded trains, along with the 3,500 resulting from future growth.....
An alternative way to increase capacity on the route would be to increase the number of tracks from the Surbiton area to central London from four to six, but this is only realistically achievable by means of tunnelling over a long distance. Such a tunnel would need to fit into a cross-industry strategy for future underground lines in the capital in general. The RUS has therefore worked closely with Transport for London to identify a variant of the currently safeguarded Crossrail line 2 route, and this forms Option F7 in this RUS.
Clearly, the SWML (South West Main Line) has serious capacity issues and Crossrail 2 is being mentioned as a solution. But looking at the problems with Crossrail 1 as I have done above, its clear that the SWML can be relieved at a lower cost by reusing part of Crossrail 1 being built now.
The Swanlink proposal connects the SWML to the Stratford branch of Crossrail.
The principle is to acknowledge that Crossrail 1 is actually "one and a half crossrails". By building the aditional "half a crossrail" linking to the SWML, it is converted to 2 independent Crossrail lines each with 24tph - one from west of Paddington to Canary Wharf and Abbey Wood ("Wharflink"), and one from the SWML to Stratford and Shenfield ("Swanlink" - South West ANglia).
The junction at Stepney Green is to the east of Whitechapel so thats where the proposal must start. The first point to note is that there will need to be an interchange between Wharflink and Swanlink. The second point to note is that many commuters will want to travel from Stratford to Canary Wharf, changing at Whitechapel (it will be faster than changing to the Jubilee line at Stratford). As such, an interchange at Whitechapel makes sense. This should be designed so that passengers can easily travel from Stratford to Canary Wharf and vice versa. This requires a same-level interchange between passengers travelling west on Swanlink and east on Wharflink, and vice versa. The best design for this station is to place the two new platforms directly beneath the platforms being built now, reusing all of the surface access facilities.
The next point to note is that most travellers from the Shenfield/Stratford route currently travel to Liverpool Street. As such, removing their ability to travel to the Liverpool Street area is unacceptable. Thus the Swanlink route needs to run to Liverpool Street. Two more underground platforms will be needed, again directly underneath those being built now reusing the surface facilities. This time, the same-level interchange must be between passengers travelling east on Wharflink to east on Swanlink, and vice versa.
The combination of these two interchanges allows a passenger to change to the other line in any direction without needing to use any stairs, escalators or lifts. This saves time for commuters, building the business case.
After Moorgate, the proposed route takes a sharp turn under Guildhall to a station underneath Queen Street north of Southwark Bridge ("Queen Street" station). This would serve the western side of the city including Cheapside, Queen Victoria Street and Mansion House. Options exist to link this station to Mansion House, Bank and Cannon Street tube stations, but modelling would be needed to determine which if any makes sense. As this section is mostly under streets it should avoid foundations.
After Queen Street, the line would turn under the Thames to reach a new station under, or just to the east of, Blackfriars Road ("Bankside" station). This station would be linked with Blackfraiars Thameslink station (at the new Bankside entrance) thus provding another key link as at Farringdon. Land is currently available south of Southwark Street to assist building work here. This station may be able to link to Southwark tube station, but this may be of limited value. From there, the line would turn towards Waterloo.
The key to the affordability of the proposal is at Waterloo. South of the station there is a taxi road at the same level as the station itself. I propose replacing this with a new through platform. My analysis suggests that the limitation of 1 in 30 for gradient means that the line would need to go under Waterloo Road, not over it, so the new platforms would be at ground level. The tunnel portal would be on the site of the Cornwall Road bus garage requiring limited demolition of 2 or 3 non-listed commercial buildings. From there it routes to the "Bankside" station described above. West of Waterloo, a new bridge over the A23 would be needed to clear the Waterloo station throat and link to the existing SWML Wimbledon slow lines, again taking 3 to 5 non-listed buildings.
The advantage of this route is that the line requires an absolute bare minimum of tunnelling, probably with just one TBM drive for each running tunnel. The platforms at Waterloo would be above ground aiding access and construction. And the route serves two stations providing good access to Bankside (where large developments are proposed) and the western City area. The problems lie with the steepness of the grdients and navigating through the maze of underground tunnels, notably at Southwark tube station.
If the City route is not possible, then there is an alternate alignment, with a single station lying between St.Pauls and Blackfriars (see map). If it is not possible to build the Waterloo surface station, then a longer tunnel would be needed with a portal potentially as far out as Clapham Junction.
Swanlink dramatically takes the benefits of Crossrail to a whole new level. Pasengers from the entire South West corner of London would be linked in with big journey time savings.
Services would run from the existing Wimbledon slow lines (including Guildford, Epsom, Hampton Court, Chessington & Shepperton) through to Shenfield. It is intended that some Woking semi-fast services would move to Swanlink, freeing up the SWML fast lines as needed by the RUS mentioned above. (The Woking semi-fasts would stop more often than now, but they would gain time not having to wait for a platform at Waterloo, and in journey times beyond Waterloo.)
By itself, linking Wimbledon to Stratford is of limited value to commuters (although it would boost travel to Westfield Stratford City). The bigger benefit is for SWML commuters to reach the City and Canary Wharf directly. City commuters currently change at Waterloo to the Waterloo & City line, the 521 bus or a bike. They would now be able to travel directly to the City without changing, perhaps saving 20 minutes or more in each direction at peak time. Commuters to Canary Wharf from the SWML currently take the Jubilee line, whereas with Swanlink they would simply change at Liverpool Street (on the same-level) to access the 24tph Wharflink service, again with a big saving of time and hassle. Its important to note that the journey from Waterloo to the north and east sides of the City are very difficult today, so there is a big benefit there too. Finally, Stratford/Shenfield line passengers get much better access to the South Bank.
|Estimated journey times|
|Journey*||Now (off-peak, TfL website)||With Swanlink||Saving|
|Wimbledon to Liverpool Street||39||22||17|
|Wimbledon to Stratford||50||30||20|
|Wimbledon to Canary Wharf||39||31||8|
|Wimbledon to Hackney||57||35||22|
|Wimbledon to Hoxton||51||32||19|
|Wimbledon to Woolwich||51||38||13|
Clearly these new links would greatly relieve the Waterloo & City line and the Jubilee line. Given the queue for the Waterloo & City (and crush conditions), this is a very good thing.
Finally, the plan permits 24tph between the City and both Stratford and Canary Wharf, a key design goal itself, reducing the inevitable overcrowding that will occur when Crossrail opens. Beyond those two stations there is no need for 24tph. Therefore, investment could be made to add new branches - to Barking, Upminster, Brimsdown or Chingford beyond Stratford, and to Dagenham/Grays or Thamesmead/Grays beyond Canary Wharf. These would be independent investments and are not included in the Swanlink case presented here.
The cost of Swanlink can be roughly estimated by comparison to Crossrail. That project has a budget of about £15bn. Swanlink is probably between a quarter and a third the size of Crossrail. It would have less initial setup costs (as it would follow on from Crossrail's up front investment), and also re-uses facilities at Liverpool Street and Whitechapel. The relatively short tunnel and surface station at Waterloo help keep costs down. An initial estimate suggests a figure around £4bn.
The quantifiable benefits arise mainly from journey time reduction, which would be considerable given current change to the crowded Waterloo & City line, 521 bus or Jubilee line. Further benefits accrue from the Wider Economic Benefits regime (Moving to more productive jobs, agglomeration effects, etc). Serving the Nine Elms regeneration area is clearly a huge boost.
Direct revenue can also be raised. The proposal also serves some London boroughs currently paying the lower levels of the Mayor's Crossrail Levy - increasing this to the higher level would also directly raise cash.
Swanlink also reduces the pressure on the SWML outlined in the London & South East RUS which advocated building Crossrail 2. Since Crossrail 2 (Clapham - Hackney) would be a £15bn+ project, and Swanlink is a £4bn project, so there is clearly a saving to be priced into the business case. Potentially, that £11bn difference is enough to justify Swanlink by itself. In addition, 5 terminus platforms at Waterloo are freed up, which can be used by other services, reducing the need to invest in bringing the Eurostar platforms back into use for SWML services, another saving that can be factored in.
Overall, I'm confident that the CBR for Swanlink would be good.
Swanlink is a logical extension to the current Crossrail scheme that suffers from having two eastern branches which divide too close to the City. By linking Stratford eastern branch and the RUS identified gap on the SWML a coherent transport solution is obtained. By reusing the Stratford tunnel and portal large cost savings are obtained, ideal in the age of austerity. The benefits to South West London are huge, with the Stratford/Shenfield and Canary Wharf/Abbey Wood lines also benefiting from more frequent services.
I hope that readers use their imagination and see how this investment makes sense and could really make Crossrail shine! There really is no cheaper way to get a second Crossrail line in London.
If you back the proposal, or have any other opinions, why not leave a comment!