3-034-809 - The Print Collector/Heritage Images

Holborn Valley Viaduct: section of subway, south side, at west end of viaduct, 1871. '...the Corporation of London determined to introduce subways for gas, water, and telegraph pipes, and thus to prevent the breaking up of the road surface...The conveyance of gas...requires special arrangements for ventilation to prevent the risk of explosion, and the subways under the Viaduct are believed to be the first constructed with a view to their safety when used for this purpose...In each subway a 14-inch main pipe of the New River Company is carried by iron chains...and above it 10-inch gas mains...are supported on iron brackets projecting from the wall...Branch pipes are laid on from the subways to the street watering-posts and to the fire hydrants in the streets, and gas is laid on to the street lamps...Rails are laid along the floor of each subway, on which runs a travelling crane, to facilitate the removal and fixing of the gas and water mains...Hitherto the ventilation has been perfectly efficient, and no danger is apprehended from the use of naked lights or from the gas jets by which the subways are lighted at times of inspection'. The Holborn Viaduct was designed by William Haywood, 'engineer of the Commissioners of Sewers'. From "Illustrated London News", 1871.