How Does The London Eye Work
The EDF Energy London Eye – A world-famous landmark that casts an iconic eye over London.
The London Eye was designed to celebrate the arrival of the millennium. It took seven years to design and build and opened to the public on 9 March 2000.
How it Work?
The Eye was such a unique engineering task that different parts of it were built throughout Europe. The capsules were built in France, the main structure in Holland, the cables in Italy, the hub and spindle in the Czech Republic and the rim bearings in Germany.
The whole wheel was assembled horizontally over the River Thames, next to Jubilee Gardens. The riverbed had to be surveyed in detail before work platforms could be put in place and they had to make sure they didn’t disrupt any river traffic. The rim was built in large sections that were floated up the Thames on barges. The height of the river had to be monitored, to ensure that they could pass under any bridges on the way to the construction site.
Europe’s largest floating crane, the Taklift 1, lifted the sections from the barges onto the work platforms, where they were attached to the hub and spindle by steel cables.
The A-frame legs of the structure are set in 33m (io8ft)-deep concrete foundations and are hinged at the base. Once the main A-frame was fixed to the hub and spindle, the hinges allowed the whole 1,900-ton structure to be lifted into its vertical position.
It took a week to lift the wheel in several stages into its present position. Tension cables set in 1,300 tons of concrete foundation were used to anchor the wheel in place. Capsules were then fitted to the outside of the rim.
The rim is rotated by sets of standard lorry tyres powered by hydraulic motors. As the wheel turns in one direction, the capsules have their own motors to slowly rotate them in the opposite direction to keep them level.
The structure of the London Eye
Spoke cables – Rim and hub are attached by 64 radial cables. There are eight rotation cables, which apply tension when the wheel turns in one direction, and eight cables for the opposite direction.
Hub and spindle – The 23m (75ft)-long cast steel spindle consists of eight sections welded together.
Capsules – Rotate in opposite direction to the main wheel to keep level. Each has an entry door at the rear of the capsule.
Compression/ tension base – The former supports the A-frame structure while the latter acts as the foundation for the back-stay cables.
Rim – The rim of the Eye is constructed from hundreds of steel tubes welded together in triangular sections.
Boarding platform – Gates ensure that passengers board the rotating wheel in an orderly fashion.
Restraint towers – Two towers guide the rim as it nears the platform, and carry hydraulic restraint guides to halt it in high winds.
Pier and collision protection boom – These are designed to protect the wheel from any river vessels that might accidentally hit the structure.
Back-stay cables – Four of these cables anchor and stabilize the A-frame to its concrete base.