The passenger capsules of the London Eye incorporate an entirely new design form for observation wheels. Instead of being suspended under gravity they turn within circular mounting rings fixed to the outside of the main rim, thereby allowing a spectacular 360 - degree panorama at the top.
The London Eye uses two types of cable, wheel cables and backstay cables. Wheel cables include 16 rim rotation cables, and 64 spoke cables, these are similar to bicycle spokes and stretch across the wheel. There are six backstay cables, which are located in the compression foundation.
The compression foundation is situated underneath the A - frame legs; it required 2,200 tonnes of concrete and 44 concrete piles - each being 33 metres deep. The tension foundation, holding the backstay cables, used 1,200 tonnes of concrete.
The main elements of the hub and spindle were manufactured in cast steel. The spindle was too large to cast as a single piece so instead was produced in eight smaller sections. Two further castings, in the form of great rings, form the main structural element of the hub. The hub is a rolled steel tube forming the spacer that holds them apart. All the casting was carried out by Skoda Steel.

Source: BA London Eye