My favorite part by far of visiting the Tower Bridge was venturing into the engine rooms below street level. The green and black coal-powered hydraulic engines reminded me of a giant mechanical grasshopper ready to spring, and made the whole exhibition worth the admission fee. One of the biggest surprises for me during Steam Tour was how colorful some of these old engines are! If you are a fan of engines and haven’t seem my post about the London Museum of Water and Steam don’t forget to take a look.
How it works: “When it was built, Tower Bridge was the largest and most sophisticated bascule bridge ever completed (“bascule” comes from the French for “see-saw”). These bascules were operated by hydraulics, using steam to power the enormous pumping engines. The energy created was stored in six massive accumulators, 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 about a minute to raise to their maximum angle of 86 degrees.” From the Tower Bridge website.
For more information and pictures from my visit to the Tower Bridge, check out Parts 1 and 2.
Due to increased commercial activity along the Thames in the 19th century, the city of London needed to create bridges to allow access to both sides of the river without hindering the approach of tallships like the Cutty Sark (see above). To accomplish this goal, a committee was formed in 1877 to decide on a design for either a tunnel below the river or a bridge that allow traffic to cross over the water. More than 50 designs were considered before Sir Horace Jones’ hydraulic drawbridge was chosen in 1884, which took 10 years to complete. You can see some of the design submissions here.
Though the bridge has two towers built on foundations sunk deep in the river bottom, the name Tower Bridge comes from the nearby Tower of London. The bridge gets its strength from a steel skeleton, but the designers also used Portland stone across the facade to add a cosmetic touch.