Original Lifting Accumulators for Tower Bridge

The deck of Tower Bridge spanning the River Thames, was originally lifted to allow ships to pass under it by an innovative steam and hydraulic system. The steam, as with most systems of this period, was powered by coal brought in by coastal steamers to the London Docks. The design of the original lifting mechanism was carried out by John Wolfe Barry assisted by Henry Marc Brunel, son of Isambard Kingdom Brunel.

This steam drove an horizontal tandem steam engine, that pumped water under high pressure to an early form of energy accumulator, shown in this picture. This high pressure hydraulic accumulator then, using an innovative control system, released the water under pressure to power a hydraulic motor driving the cogs, shown in a previous picture, that then drove meshed cogs that lifted the roadway section of the bridge.