New York's High Line is one of the most successful redevelopment projects in recent urban history. A mile-long section of a former elevated freight railway that was mothballed in the 1980s, it re-opened in 2009 as an urban park, and has become a huge hit with both tourists and Manhattanites alike: a project that has been a catalyst for regeneration, and one so successful that it has begun to attract a critical backlash.
London doesn't want for disused infrastructure, which got us wondering: could our city have its own High Line? Turns out we weren't the only ones pondering the idea: in early October the Garden Museum is running a High Line Symposium, at which the project's founders will visit London and discuss how they brought it to fruition. Simultaneously, the Mayor's office is launching A High Line for London: Green Infrastructure Ideas for a New London Landscape, an open competition to "design innovative new places that enrich London’s Infrastructure".
The competition's organisers "are not seeking a replica of the High Line", but we thought it'd be interesting to consider where it might work in London. Add your own suggestions in the comments.
Broad Street viaduct
What is it? The truncated southern stretch of the old Broad Street - Watford line, which closed in 1986. Much of the Kingsland Viaduct (which itself would've made a good candidate) was re-opened as part of the East London line extension in 2010, but the original terminus was at the now-demolished Broad Street station. There remains a derelict rump just north of the Broadgate Tower that extends as far as Great Eastern Street.
Why it'll work: This long-neglected stretch of railway could soon be emerging from its early retirement. Renderings for a proposed tower on Great Eastern Street show the Broad Street viaduct as an urban park.
Why it won't: The project has yet to be approved, and use of the park may be limited to residents only.
Bishopsgate Goods Yard
What is it? Next to Shoreditch High Street station, the former Bishopsgate Goods Yard has an elevated section, the Braithwaite Viaduct, running between Bishopsgate and Brick Lane.
Why it'll work: Plans have been lodged with Tower Hamlets for some years to make the old goods yard the centrepiece of a green strip running between the City and Allan Gardens. It's a perfect spot for an urban park, in an area popular with tourists and locals.
Why it won't: Given the proximity to the Square Mile and the the gentrification of Spitalfields over the past decade, the land is highly valuable. More Boxpark-like endeavours that exploit the area's high footfall and wealthy visitors may appeal more to planners and council members than a park. Parts of the viaduct are listed, which may reduce opportunities for development.
What is it? Formerly part of the London and Blackwall Railway (LBR), the Limehouse curve closed in 1962. While much of the LBR has since been re-used for the Docklands Light Railway, the Limehouse curve, consisting of a short viaduct and an iron bridge over Commercial Road, remains derelict.
Why it'll work: There are already a couple of plans knocking about to convert the bridge into a park. A project on Spacehive is seeking crowd funding, while a quixotic page on the What If website has details of how it might work.
Why it won't: Even Limehouse locals would probably concede that their patch of the capital isn't the most beautiful. Would there be much appeal in elevated views of Commercial Road?
Rail bridge over Waterloo Road
What is it? A bridge that once carried a railway linking the platforms at Waterloo station with the Charing Cross - London Bridge line. The link was severed in the 1950s, and the bridge is now used for storage.
Why it'll work: It would be quite easy to clear out and re-purpose.
Why it won't: Does anybody really want a view of Waterloo Road? It might work as a coffee shop or cafe, but nothing more.
Why it'll work: It would offer choice views of some picturesque parts of London, including Little Italy and the Paddington Basin.
Why it won't: Last time we checked it was chock-full of cars, and without a substantial municipal shift away from the automobile, the Westway's future as a major conduit into the capital is pretty much secured. Besides, there's the problem of the Ballardian scenario that awaits anybody foolish enough to fall over the edge.
What is it? Structurally-imperiled elevated road that lifts traffic clear across the congested Hammersmith gyratory system.
Why it'll work: The flyover isn't in great shape, and despite recent reinforcement work the long-term future looks bleak. Ideas for alternative schemes are already being entertained, including a tunnel. Instead of demolishing the flyover it would be relatively simple to turn it into an elevated urban park.
Why it won't: Locals might object to what many consider a blighted concrete eyesore being left in place when its prime purpose has been removed. Also, the tunnel idea is at best many years away from ever coming to fruition.
What is it? We're cheating a little here, but instead of building above ground, why not below it? The Aldwych Tram tunnel runs between Southampton Row and Aldwych, and was closed in the 1950s; today it's used by Transport for London as a storage facility and hosts the occasional artwork.
Why it'll work: It's in a central London location and, given the right kind of work, could be made into a beguiling place to visit. Being underground might be a disadvantage, but would make it an all-weather attraction.
Why it won't: It's a bit dingy down there, and it might take a lot of work (and artificial foliage) to convert it into a park that people would actually enjoy using. Also, the tunnel is currently being used as an access point during the Crossrail tunnelling project.
Here's one we made earlier: Parkland walk
What is it? A railway from Finsbury Park to Muswell Hill that was mothballed in the 1950s and converted into an walking route in the 1980s.
Why it'll work: It already does — the Parkland Walk is hugely popular among locals.
Why it won't: There are sporadic campaigns to re-open the railway line, but it has no serious level of support.