James Henry GreatheadBorn 6 Aug 1844; died 21 Oct 1896 at age 52.English civil engineer, born in South Africa, who improved tunneling shield methods which he applied during construction of the London Underground. The technique was originated by Marc Brunel and subsequently modified by Peter W. Barlow as a smaller shield of circular cross section. Having learned its use from Barlow, Greathouse utilised the shield with his own further improvements to complete the Tower Subway (1869) under the River Thames near the Tower of London. He adopted screw jacks to push the shield forward while the tunnel behind it was lined with cast-iron rings, and pioneered the use of compressed air to prevent flooding during the lining installation. His statue beside the Royal Exchange was erected in 1994.« |
