When it opened in 1894, London’s Tower Bridge was hailed as a triumph of Victorian engineering. It was the largest and most sophisticated overpass of its kind in the world, using hydraulic steam engines to raise and lower the two bridge sections (known as bascules, from the French for “see-saw”) to allow ships to pass through. The elevated, open-air walkway that gives the bridge its distinctive profile allowed pedestrians to cross the Thames when the bridge was raised. The bridge’s architects concealed the structure’s high-tech engineering by cladding the steel infrastructure in Cornish granite and Portland stone to match its namesake, the nearby Tower of London.
