ALL 32 CLUTCHES on the millennium wheel are to be replaced following analysis of a failed unit discovered just before Christmas.
The changeover could set back the London Eye's opening until mid-February.
The clutches are supposed to drive a levelling mechanism on the passenger capsules as the 135m high wheel makes its half-hour sightseeing circuit. One unit failed to disengage during commissioning tests (NCE last week).
Engineers with project manager Mace and safety check consultant Allott & Lomax travelled to the Midlands last week to see the failed unit stripped down by manufacturer Stromag.
The German firm has a base in the UK, although the units were originally supplied via a French distributor to capsule maker Poma of Grenoble in France.
Within hours it was clear that the failure had been caused by two components jamming inside the clutch, said Mace project manager Tim Renwick this week.
It is thought these components were not produced to the exact tolerance required by the design.
'Though the full story is not clear yet, we are sure it was a manufacturing fault and not a design problem,' said Renwick.
The replacement units for the clutches would be 'exactly the same design,' he added, 'which is essentially a design based on technology 30 years old.'
Just how much the changeover will cost and how long it will take is not yet clear. But it is likely to be mid-February before the wheel is fully operational.
Wheel sponsor British Airways refused to comment this week, except to say that the official opening of the wheel had always been timed for February.