By the last quarter of the nineteenth century, commerce in the East End had reached such levels that it was necessary to build a new bridge to support its development. The committee in charge of selecting the design had to contend with the difficulty of late nineteenth-century river traffic, which led to the final choice of a two-level bridge: a lower bascule bridge which could be raised to allow tall-masted ships to pass, and an upper walkway which pedestrians could use at all times.
Construction of Tower Bridge, which earned its name due to its proximity to the Tower of London, began in 1886 and lasted eight years. It required a monumental engineering effort, not least in the creation of the hydraulic system used to operate the bascules. Its huge pumping engines were driven by steam until 1976, when they were replaced by an electrical system.
The upper walkway was seldom used and became a haunt for criminals and prostitutes, leading to its closure in 1910 - which seems a rather unexciting decision - although it gained a new function during the First World War as the site for some of the many anti-aircraft guns installed to protect the city from German zeppelins.