A huge challenge faced the City of London Corporation: how to build a bridge downstream from London Bridge without disrupting river traffic activities. To generate ideas, the Special Bridge or Subway Committee was formed in 1876, and a public competition was launched to find a design for the new crossing.

Over 50 designs were submitted to the Committee for consideration, some of which are on display at Tower Bridge.

It wasn't until October 1884 however, that Sir Horace Jones, the City Architect, in collaboration with Sir John Wolfe Barry, offered the chosen design for Tower Bridge as a solution.

When it was built, Tower Bridge was the largest and most sophisticated bascule bridge ever completed ('bascule' comes from the French word for 'seesaw').

These bascules were operated by hydraulics, using steam to power the enormous pumping engines. The energy created was stored in six massive accumulators, meaning that as soon as power was required to lift the Bridge, it was always readily available. The accumulators fed the driving engines, which drove the bascules up and down. Despite the complexity of the system, the bascules only took 60 seconds to raise to their maximum angle of 86 degrees.

Today, the bascules are still operated by hydraulic power, but since 1976 they have been driven by oil and electricity rather than steam. The original pumping engines, accumulators and boilers are now on display within the Bridge’s Engine Rooms.

Tower Bridge has many connections to the royal family, from Queen Victoria to Queen Elizabeth II and before. These connections can be traced back to long before 1894, when London's defining landmark was officially opened to the public.