4th January 2019 • Tower Bridge Blog
How does Tower Bridge work? Part 2
In our previous blog post we talked about Tower Bridge being a bascule bridge and how it opens, this month we’ll uncover how it was powered, from when it was first built in 1894 up until 1976.
Steam was the energy of choice during most of the 1800s. The London Hydraulic Power Company powered much of London, including workshops, lifts, cranes and even theatre machinery. At Tower Bridge, power was generated by three large boilers, continuously fuelled by stokers working in shifts, 24 hours a day, to ensure there was enough energy available to lift the bridge whenever required. The steam created in these boilers was used to power the large steam pumping engines in the next room.
These engines are brightly painted and resemble a steam train when they move. The engine’s pistons turn a large flywheel at the same time as powering a set of hydraulic pumps, which pushes water into six huge storage containers called accumulators. They act like batteries, storing the energy by holding the water under high pressure.
Then, when the bridge was required to open, the water was released into the drive engines, powering yet more pistons to turn a set of cogs. These cogs connect to a rack on the back of the bascules, opening Tower Bridge for passing river vessels.
Cogs are still used today to open Tower Bridge, but the power is generated in a different way. Come back next month to find out how the bridge is powered today.
Interested in seeing the machinery described above? They’re all on display in the original Victorian Engine Rooms inside Tower Bridge. Plan your visit today.