 Tower Bridge has stood over the River Thames in London since 1894, and is one of the most recognizable bridges in the world. The bridge was completed in 1894 after 8 years of construction. Originally, London Bridge was the only crossing over the Thames. Other bridges were later added to the west, and as London grew larger, there was a need for another large bridge in the east. The problem was how to build a bridge without disrupting river traffic activities in the area. It took 8 years and the labour of 432 construction workers to build Tower Bridge. Two massive piers had to be sunk into the river bed to support the bridge, and over 8600 tonnes of steel were used to make the towers and walkways. The bridge was then covered in stone to protect the steel and to make the bridge look more pleasing. When it was built, Tower Bridge was the largest and most sophisticated 'see-saw' bridge ever built. Originally, huge steam engines applied hydraulic pressure to lift the bridge deck; since 1976 the power comes from oil and electricity. |