Hand-coloured. Marc Brunel's Thames Tunnel between Rotherhithe and Wapping was the first underwater tunnel in the world. Several attempts to construct a tunnel under the Thames had failed by the time Brunel patented a tunnelling shield in 1818. Five years later Parliament authorised his plan to use the shield. It worked by exposing only a small proportion of the excavation face, thus reducing (although not eliminating) the chances of the tunnel collapsing. Opened in 1843, the tunnel was used solely for foot passengers until the 1860s, when it was converted to carry the East London Railway. It still carries trains of the East London Line, now part of the London Underground.