London's derelict tube tunnels reimagined
as a pedestrian and cycle network

The London Underline by Gensler

News: architecture firm Gensler wants to repurpose London's abandoned tube tunnels to create a subterranean network of pathways that generate electricity as people walk and cycle through them.

The proposal – named the London Underline, in a kind of mash-up between the London Underground rail network and New York's popular High Line park – suggests that the city's disused tunnels could provide the answer to overcrowding on other transport routes.

The London Underline by Gensler

London's underground network includes a number of old stations and tunnels that have been retired from service and now sit empty. These neglected spaces could offer cycleways that are safer and less crowded than the roads, but could also host to pop-up shops, cafes and cultural offerings for pedestrians, says Gensler.

"Now that London has reached the highest level of population in its history, we need to think creatively about how to maximise the potential of our infrastructure," explained Ian Mulcahey, co-director of Gensler London. "The adaptation of surplus and underutilised tube and rail tunnels could provide a quick and simple addition to our infrastructure network."

The firm proposes using a system called Pavegen instead of conventional paving slabs to line the tunnels. These engineered surfaces convert energy from footsteps into electrical power.

More of these slabs could also be integrated into the ground at a well-used train or tube station – the firm suggests Charing Cross or Holborn – to ensure the network produces more energy than it uses.

The London Underline by Gensler

"Gensler's proposal brings back an ignored part of the city through the collective efforts of its citizens," said designer Trevor To. "By harnessing the kinetic energy of everyone's footsteps, a whole new urban space is unlocked underneath the city."

"This self-sustaining approach to urban infrastructure is key to a carbon-neutral community, and London could lead the world once again in merging tradition with innovation to create a better future," he added.

The London Underline by Gensler

The first tunnels under consideration are a series of underground spaces in central London, between the existing stations at Green Park and Holborn, as well as the now-defunct Aldwych, which would act as access points.

To link disconnected sections, old reservoir chambers and exchanges would also be surveyed for reuse – part of what the firm describes as "an untapped surplus of disused space in subterranean infrastructure".

The London Underline by Gensler

Gensler isn't the first firm to propose an alternative to cycling on London's roads, which hit the headlines at the end of 2013 when six cyclists were killed in a two-week period.

London mayor Boris Johnson recently approved plans to create Europe's longest segregated cycle lane through the city centre, while a team including London firm Foster + Partners previously unveiled a concept to build a network of elevated pathways above London's railways.

  • M. Vitruvius

    I guess there are some people who are much happier moving about deep under the city. Far away from the daylight and fresh air.
    I don’t know any but yeah, I guess there are some.

    • John

      “Fresh air” – you obviously don’t live in London ;)

  • Delbert Grady

    Oh the wars that will be fought over foot energy.

  • Osama Aboelezz

    I find it a great idea for cycling, since London is actually not that safe at all for cyclists. But I doubt it would be that enjoyable for pedestrians, unless there is something extremely unique down there!

  • Charlotte

    Last year our project which opened up the same line at Aldwych for pedestrians, cyclists and swimmers was shortlisted for the AJ’s Forgotten Spaces award. VERY similar idea only ours aimed to open up the street where possible to let light and the external environment in. It wasn’t closed off by the use of an Oyster card, which I have read elsewhere is the suggestion for this one. One page from our competition entry is attached here…

  • F. Uming

    I totally want to sip a coffee next to people painting graffiti (in a tunnel!).

    • Ken Johnson

      Do you seriously think a graffiti artist with an ounce of self respect will paint in an authorised graffiti area?

  • Nelvea

    I live in Montreal where we have the biggest underground complex in the world. It is a FANTASTIC thing. Ours connects shopping malls, subway stations, office buildings… some corridors are very bleak but we authorize musicians (with permits) to perform in those and sometimes they are transformed into art galleries for special events. Given the harsh weather in winter, this underground network is a blessing. It also provides a shelter for homeless people during cold winter months. They are tolerated as long as they don’t do anything illegal or disturbing to other users.

    I find the idea is a good one for London, a good starting one. As the network expands and users make requests/suggestions, it would only get better with time. No system is perfect anyways.

    • iag

      One key difference, Montreal weather is extreme. London is not. Even in the heart of winter London rarely drops below freezing.

      • Concerned Citizen

        Does it ever rain in London?

        • Hugh

          Surprisingly, not that often. In a year of cycling to work from Waterloo to Faringdon, I got rained on twice.

          • Concerned Citizen

            I have visited London half a dozen times, for a week to ten days at a time, and was rained on every day. You may not have been alive then.

          • Hugh

            It may have rained that day but not between 8:00 and 8:20am.

        • iag

          Since when was drizzle and a bit of rain considered extreme? We don’t get monsoons, typhoons, deep freezes etc.

          The cost of such a thing would be very hard to justify just to stop cyclists getting a little wet once in a while.

          I’d echo Hughs comment on how infrequent I’ve gotten wet during the morning and evening commute.

          • Concerned Citizen

            Re-read these comments, with comprehension this time. Move your lips if need be. Nowhere will you mouth the word “extreme” until you get to your own myopic comment.

          • iag


            Concerned Citizen, should be more like Clever Clogs Citizen.

            “harsh weather in winter” appears, but you are correct, the word “extreme” first appears in my comment.

            However, the reason why such a thing was introduced (and works) in Montreal is because of the climate, however you choose to word it.

            You directly responded to my comment about climate differences between London and Montreal with ‘Does it ever rain in London?’, thus drawing direct comparison between London’s sporadic rain and Montreal’s “harsh” winters.

            My logical follow-up comment reiterating London’s climate in no way warrants underground walkways or cycle-paths stands.

            Simple. When you’re not being a clever clogs that is.

          • Concerned Citizen

            I made no reference to Montreal. Where do you get that crap?

          • iag

            A quick scan of even your Dezeen comments throughout this site indicates a serious case of what some might refer to as ‘haters gonna hate’ and an even worse case of condescending smarty-pants fever.

            I’m sure you are nothing like the majority of online haters who smear sites like Dezeen with negativity when you have in reality achieved relatively little. I’m sure you have an outstanding portfolio of built architectural and design masterpieces. For sure.

          • Concerned Citizen

            Well, I do agree that you are simple.

  • Beth Williams

    A fascinating idea! Although there would be considerable expenditure required for considerable engineering work perhaps the disused Post Office Mail Rail tunnel from Paddington to Mount Pleasant could also be incorporated into London Underline. Let’s shut down the ridiculous Thames Cable Car which is hardly used and allocate the money towards the type of transport improvement which would be of benefit to large numbers of people.

  • T. Urk

    The girl in the video is a little bit lovely. If people like that are using it I’ll be there everyday!

  • Gressier&co

    Fantastic idea. Lateral thinking at its best. Why do politicians insist on vanity projects rather the simple, logical, sustainable and comparatively better value solutions like this!?

    One of the main issues with cycling in London are safety from car traffic and the lousy weather…. Both solved! Well done.

  • d j

    Stick all the cars and motorbikes underground instead.

  • oliverft

    The spray paint/art idea in a tunnel with people in close proximity… just saying.

  • iag

    I’m all for reusing unused/under-utilised spaces. However, from a practical point of view, does the London underground passageways (not the main ‘lobbies’) allow enough space for two lanes of bicycle traffic travelling in opposite directions from one another? Arched tunnels, head clearance on a bicycle etc?

  • James

    London should deal with its housing crisis first. It’s bad enough that we have to deal with vanity projects, but intolerable that authorities, planners and designers aren’t getting priorities in order.

    • Ken Johnson

      Is it possible to convert the Holborn/Aldwych/Waterloo tunnel into a Salivation Army dormitory for the homeless?

  • It’s a great idea, if commuting was cheaper, safer, easier and greener then there wouldn’t be the same issues surrounding housing in London. The idea of utilising what already exists and reinvigorating historic structures surely can’t be a bad thing.

  • Concerned Citizen

    Underground. I couldn’t think of a better place for those ill-dressed, obnoxious, lawless bikers.

  • RobertWilliamMayers

    John, the freshest air in London is to be had while walking – closely followed by cycling and the worst air is in cars. I was quite surprised by this fact too but it’s good to know.

    And as a general point, the strategy of trying to find ways around the existing number of private vehicles on the road is not sustainable and proposals like this one does nothing to move discourse forward.

  • Londo-er

    I don’t know if anyone has missed the main issue with tunnels, but should anyone have graced the tunnels at the foot of Centre Point before the refurbishment works, they would smell the problem.

    Tunnels and underpasses are notoriously unsafe cesspools that would certainly be home to less than pleasant matters. One plus might be that these tunnels will offer homes for the “homeless”, given the warm living conditions and potentially undisturbed sleeping areas. Not a bad thing one might argue, but then would anyone use these?

    I for one would not walk here on my own at night, or day since there is no natural light or easy routes for escape…..

    Poor idea Gensler. Improve the segregation of cars, bikes and people by elevating areas of roadway similar to the successes of Chicago and New York. I for one don’t mind rain when the alternative is to trap people in tunnels under ever-congested city streets.

  • urm

    Nice idea, but the Pavegen system produces less energy over its lifetime than the energy required to make one. Just sayin.