Beneath the Thames in East London lies a pioneering tunnel, the like of which Victorian society had never before seen. The Thames Tunnel was the world's first tunnel to be built beneath a navigable river, and its construction pushed forward the very frontiers of engineering. Even better, the tunnel still exists, it's still open, and tens of thousands of people travel through it every day. Because the Thames Tunnel, constructed more than 150 years ago, lives on as the tube line between Rotherhithe and Wapping on the EastLondonLine.
The Thames Tunnel is a Brunel construction, but was masterminded by Sir MarcBrunel rather than his more famous son Isambard. The tunnel took 18 years to complete, mainly because the soft clay beneath the Thames proved an absolute nightmare to dig through. Marc solved the twin problems of flooding and subsidence using solutions that were, literally, cutting edge. First he built a huge cylindrical shaft on the surface (see right of photo), then he got his miners to dig inside until the structure had sunk down beneath the level of the riverbed. Then he built a big engine house (see left of photo) to pump invasive water out of the tunnel works. Finally, and cleverest of all, he invented the tunnelshield, allowing his miners to edge slowly forward without the risk of London caving in on top of them. The same principle is still in use in civil engineering projects around the world today.
There were several deaths during the construction process, notably in early 1828 when the Thames broke through a weak spot in the roof of the tunnel, flooding the lower chambers and drowning several of the miners. Young Isambard, who had been supervising work in the tunnel at the time, escaped with serious internal injuries after swimming frantically to safety. Work stopped for seven years, and even then it was another seven years before the tunnel was finally opened to the public. Fashionable Victorians flocked to promenade through this new underwater marvel, an amazing twin-bore arched corridor lit by flickering gaslight. Two million visited in the first year alone. Gradually market traders and hawkers moved in until eventually the tunnel became a seedy backwater haunted only by pickpockets and prostitutes, surviving only as a curiosity. In 1865 the tunnel was sold to the East London Rail Company who laid tracks and ran services through from the Metropolitan line.
The Engine House just north of Rotherhithe station is now a small museum telling the story of the tunnel and the people who constructed it. It's only a small exhibition but it's packed with information and artefacts, and £2 feels a fair entrance price. You can read all about the Brunels and their subterranean struggle, peruse displays of tunnel-related ephemera and squint into a cardboard Victorian peepshow to get a feel of how the tunnel must have looked in its heyday. In the lower gallery there's also 20 minute video to watch, although half the film appears to be a London Underground propaganda piece explaining why ten years ago they felt the need to close the tunnel and spray almost all of Brunel's original brickwork with concrete 'for safety reasons'.
Here's the Thames Tunnel today, as seen from the northbound platform at Wapping station. The left-hand tunnel isn't normally illuminated, but it was yesterday afternoon as part of a special tour (and will be again this afternoon and next weekend). The Brunel Engine House Museum are arranging hour long 'guided journeys' under the Thames for a fiver (bring your own rail ticket), and I bumped into one of these tours at the mouth of the tunnel yesterday. At least 60 people were trying hard to concentrate on the commentary being given by the young French guide, and I managed to listen in from the opposite platform for a few minutes for free. The guide cunningly illustrated his talk with the aid of the many beautiful historical pictures on the panels that line the platform at Wapping, then ushered his group onto a passing train to return to Rotherhithe. On the way they enjoyed a sensitively-restored section of tunnel from its floodlit interior, although I doubt they saw much detail passing through at such close quarters. Book your place for next weekend here. This may no longer be the eighth wonder of the world but it's still well worth a pilgrimage. by tube: Rotherhithe, Wapping