Inside Tower Bridge. A steam engine that was part of the original raising mechanism. There were two 360hp horizontal twin-tandem compound engines. A 3rd backup engine was added in 1942. The original steam mechanism was replaced in 1974 by an electro-hydraulic drive.

One of the bridge's two control cabins for operating the bridge -part of the replaced mechanism.

When it was steam powered, water under high pressure was stored in these hydraulic accumulators. There were six of them.