The Worm That Taught Engineers to Dig Under a River

In 1825, London tried to do what the experts had called impossible: dig a tunnel under the River Thames. It took 18 years, six floods and six lives in a single night, and an idea borrowed from a clam that eats ships. Sources Thames Tunnel (Wikipedia) Tunnelling shield (Wikipedia) Marc Isambard Brunel (Wikipedia) Isambard Kingdom Brunel (Wikipedia) Transport for London, The Thames Tunnel