The Thames Tunnel
The Thames Tunnel was the first tunnel under a navigable river, and has been a tourist attraction for many years. However it took twenty years to build and was almost never completed when its backers ran out of money.
The main architect of the tunnel was Marc Isambard Brunel, father of the famous Isambard Kingdom Brunel but also a famous engineer in his own right. He had designed and patented a tunnelling shield that he believed would make tunnelling safer faster and cheaper.
The tunnelling shield was a wooden frame that was constructed at one end of the tunnel. The diggers stood within it and dug out the soil beyond. Once enough was dug out the entinre frame was moved forward and bricklayers built the tunnel’s shell behind it. Brunel had designed it so carefully that only four and a half inches of soil would show behind it.
He managed to get backers from a range of people, including the Duke of Wellington, and construction began. Working conditions were poor, and although the tunnel did not collapse or flood in the early stages, sewerage-contaminated water from the Thames seeped in making the workers ill.
When the chief engineer fell sick, Marc Brunel appointed his son Isambard, aged twenty and fresh from his apprenticeship with another engineer firm. It was a decision that nearly cost his son’s life.
As they dug further under the Thames, the tunnel came to close to the riverbed and flooded. The first time, the hole was plugged and they continued. The second time was catastrophic. The tunnel flooded suddenly, killing six men. Mr Beamish, a tunnel worker, hauled another worker unconscious from the water to discover it was Isambard Kingdom Brunel.
Isambard Kingdom Brunel’s injuries were severe and he was sent away to recover. With money needed to repar the damage, and a length of the tunnel needing to be dug out again, a few months later the tunnel was boarded up and work ceased in 1828.
By 1836 Marc Brunel had secured enough funds to continue, although the tunnelling shield had rotted and a new one had to be constructed. The new construction would again be dogged by problems, from the sandy soil of the Thames, to fires and flooding. It would take a further seven years until 1843 when the tunnel would finally be opened to the public.
Initially it took foot traffic, and functioned more as a tourist attraction with booths in alcoves along its length. However in 1865 it was purchased by the railway and converted for trains.
Still used today, it is now a vital part of the tube network, forming part of the East London Line. However, repair work over the years has changed its appearance, and it is currently undergoing further work as part of the crossrail project. The tunnel should reopen in 2010.
The Brunel Museum was set up in its original pumping house at Rotherhithe, to tell the story of the tunnel.
And the tunnelling shield? That principle forms the basis for all modern tunnelling work, including the Channel Tunnel.
A Visit to the Brunel Museum
L.T.C. Rolt’s biography of Brunel