Europe’s biggest construction project is underneath London


Click to enlargeCrossrail/PA

Creating a new 118-km rail route with 10 new stations and 42 km of new tunnels is no mean feat. The logistics of doing so in one of the world’s major cities, however, are staggering. That is the task for the UK’s Crossrail line. Major tunneling ends in May, so Gizmag went to take a look…

Work on Crossrail began in 2009 and the route is expected to start operating in 2018. Once completed, it will link Reading and Heathrow to the west of London with Shenfield and Abbey Wood to the east. The route goes directly through Central London, meaning that not only is it a huge undertaking, but one that is incredibly complex.

The facts and figures about Crossrail are mind-boggling. Over 10,000 people are employed across 40 construction sites. It is expected to increase rail capacity in London by 10 percent in a stroke, and will bring 1.5 million more people to within 45 minutes of the city’s major employment areas. Over 6 million tonnes (6.6 million tons) of excavated material will be removed to create tunnels at depths of up to 40 meters.

The list goes on, but perhaps the most remarkable aspect of the project is the tunneling itself. Not only must miles of new tunnels be created underneath London, but they must be created without disturbing the ground and buildings above, and avoid the subterranean tangle of existing tunnels, cables, sewers and so on…

The Crossrail tunneling has been being carried out using a total of eight tunnel-boring machines…Each machine is 150 m long and weighs 1,000 tonnes…They burrow an average of 100 m per week, with one machine setting the record of 259 m in a week. The clay and rubble excavated by the machines is transported out of the tunnel on a conveyor belt fed out behind them.

As they bore through the ground, the TBMs lay preformed concrete segments around the inside of the newly-dug tunnels. These form “running tunnels” that the future trains will run through. To create the much larger platform tunnels from where passengers will board trains the concrete segments are then removed so that the tunnels can be widened. The sides are then sprayed with a concrete mixture called “shotcrete” that contains steel fibres…A “shutter machine” then moves along the tunnel adding a final concrete lining…

Once Crossrail’s tunneling work comes to an end, much of the focus will move on to installing and setting up the required railway systems, as well as building and fitting out stations.

Something like this has to dazzle Americans. Excepting a few cities and states with the buck$ and determination to move beyond the constraints of American politics, there isn’t any consideration of taking on projects like this. Our politicians haven’t the backbone or economic good sense to repair and maintain the infrastructure we have – much less step towards the future.

2 thoughts on “Europe’s biggest construction project is underneath London

  1. Al says:

    “Once I built a railroad, I made it run
    Made it race against time
    Once I built a railroad, now it’s done
    Brother, can you spare a dime?”

  2. "They're here!" says:

    To make way for one of the new subway stations, archaeologists have began excavating a graveyard beneath the streets of London. They expect to find about 3,000 graves that date back to the 16th and 17th centuries. http://www.livescience.com/50098-skeletons-buried-under-london-photos.html Among other things, Archaeologists hope that they might be able to help scientists understand the plague-causing bacteria strain through tests on other excavated victims of the Black Death.

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