Thursday 24 March 2016

Crossrail 2 and Merton

Crossrail 2 continues to progress. The National Infrastructure Commission has backed it. And the chancellor has provided money for the next stage of planning. The next few months will be key for how Wimbledon and Merton will be impacted over the next 20 years.

Crossrail 2 and Merton

Crossrail 2 is coming to Merton and that potentially means big changes for Wimbledon, Raynes Park and Motspur Park. While it may be tempting to try and stop the scheme, the passage of the HS2 third reading yesterday in parliament indicates clearly how ineffective the "stop HS2" campaign has been. Given this, I argue that it would be wise for Merton residents concerned about Crossrail 2 to fight for improvements to the project, rather than trying to stop it altogether.

Sadly, the Crossrail 2 team only put forward one option at consultation. However there are four basic approaches which could be adopted at Wimbledon. This table summarises the impacts of each option:

Option Option 1:
Demolish to the south
Option 2:
Demolish to the north
Option 3:
Deep tunnel platforms
Option 4:
Fast line tunnel
Total amount of demolition in Wimbledon town centre Major Major Some None
Demolish Centre Court shopping centre Yes No No No
Rebuild entrance to Wimbledon station Yes Yes Yes Yes
Trams move up to street level, platform 10 destroyed Yes No No No
Tunnel portal site Gap Road Gap Road, or perhaps Waitrose Demolish 150 houses in Raynes Park, or needs two tunnel portals Wasteland at Berrylands & Weir Road industrial area
Turn-back & dive-under in Dundonald area Yes Yes No No
Widen from 4 to 6 tracks between Wimbledon and Raynes Park Yes Yes Partial No
Impact on Raynes Park station rebuild Major rebuild Major rebuild Major rebuild Smaller rebuild
Cost Baseline Assumed to be similar to basline £2bn+ more expensive In theory, should to be cheaper
Is it viable given what is currently known? Yes Yes No Yes

The four basic approaches to get Crossrail 2 through Wimbledon are:

Option 1: "Demolish to the south" - This is the current official plan, where Centre Court, the Prince of Wales and many other buildings are demolished to build new sub-surface platforms (just 10m underground).

Option 2: "Demolish to the north" - A similar approach to the current official plan, but demolishing the north side of the station instead (the taxi rank, HSBC, magistrate courts etc). Again the new platforms would be sub-surface (just 10m underground).

Option 3: "Deep tunnel platforms" - This would involve constructing two or four deep platforms (perhaps 30m underground), similar to Crossrail stations in central London. The Crossrail 2 team estimate this would cost £2bn more, and potentially involves demolition of 150 residential properties in Raynes Park. It would also require significant demolition in Wimbledon town centre for the lift and escalator shafts to the deep platforms. Since I have seen no evidence of a viable way to build this option without ridiculous residential demolition impacts, I've marked it as not viable in the table.

Option 4: "Fast line tunnel" - This involves a new tunnel from Berrylands to the Earlsfield area, taking the trains on the current fast lines. This frees up two tracks and two platforms at Wimbledon, providing the space for Crossrail 2 without major demolition. This is also known as the Swirl plan. (Note that a fast line tunnel for Merton is viable with whichever station is chosen for Wandsworth - Balham, Tooting or Earlsfield. Note also that the table describes a minimal fast line tunnel option where either all 30tph run through to the branches, or 10tph turn-back at Clapham Junction.)

A key point arising from the table is that option 2 is very similar to option 1. Both involve major demolition in the town centre, turn-backs, dive-under and widening to 6 tracks.

Wimbledon, London

As a little bit more detail, these bullet points outline the work involved for option 1 in Merton (the official plan). This is intended to help explain the rows in the table above:

  • Four new sub-surface platforms at Wimbledon station, created by demolishing much of the Centre Court shopping centre and many other buildings in the town centre
  • The loss of platform 10 from the existing Wimbledon station, permanently restricting the frequency of Thameslink services
  • Trams moving out of the station up to street level
  • A tunnel portal at the Gap Road worksite, where the main tunnel is dug from
  • A new road bridge between Queens Road and Alexandra Road
  • A turn-back facility at the Dundonald Road worksite, to allow trains to reverse
  • A dive-under at the Dundonald Road worksite, for Northbound trains to reach the new platforms
  • Two additional tracks between Wimbledon and Raynes Park (6 tracks instead of the current 4 tracks)
  • Major rebuild of Raynes Park station for cross-platform interchange and access for all, likely to involve land take north of the current station site

The construction period is likely to be around 10 years, plus subsequent work to redevelop the worksites. There are also likely to be many resulting lorry movements.

Summary

When the four options for Wimbledon town centre are evaluated side by side, it is clear that only a fast line tunnel will really improve the Crossrail 2 scheme for Merton. The key benefit is that it removes all town centre demolition apart from reconstructing the station itself. However the benefits go beyond that, avoiding the need to widen to six tracks between Wimbledon and Raynes Park, require no turn-backs or dive-under in the Dundonald area, and reducing the land take needed by the rebuild of Raynes Park station.

Hopefully the table above helps clarify why this blog is arguing that a fast line tunnel is the only option Merton residents should be arguing for (via your residents association and elected representatives).

4 comments:

  1. Idea for the Swirl's Berrylands portal - rather than truck the tunnel spoils via New Malden, it would be easy-ish to build an access road directly to the A3, bypassing most houses.

    See https://umap.openstreetmap.fr/en/map/untitled-map_80158?scaleControl=false&miniMap=false&scrollWheelZoom=false&zoomControl=true&allowEdit=false&moreControl=true&datalayersControl=false&onLoadPanel=undefined&captionBar=false&datalayers=186403#14/51.3981/-0.2660

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    1. While this is no doubt feasible in engineering terms, it would I suspect be tricky to justify financially. This is why my first choice for the portal would be where the main line meets the A3.

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    2. Ah..the table above says the portal would be "Wasteland at Berrylands & Weir Road industrial area".

      On reflection, I imagine a conveyer belt thing as used on CR1 would be cheaper than a road anyway.

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    3. A portal at Berrylands or the A3 seem feasible. The A3 is shorter and has better road access, but Berrylands avoids rebuilding New Malden station. But really, this is detail - the key at the moment is getting the principle of a fast line tunnel adopted.

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