Movable bridge of the double-leaf bascule type that spans the River Thames between the Greater London boroughs of Tower Hamlets and Sourhwark. It is a district land mank that aesthetically complements the Tower of London, which is adjoins. The bridge was completed in 1894 and provides an opening 250 feet (70 metres) wide. Its twin towers rise 200 feet (61 metres) above the Thames. Between the Towers strech a pair of glass-covered walways were originally designed to allow pedestrians to cross even while the bridge was raised. The Tower Bridge was operated by hydraulic pumps driven by steam until 1976, when electric motors were put into operation. Because of the reduction, shipping at the London Docklands, however, the leaves are now seldom raised.
