WIND SPEED safety restrictions for cladding the Millennium Dome have still not been agreed by the Health & Safety Executive less than six weeks before cladding operations start.
The maximum wind speed at which cladding can be installed will have a major influence on supply and fix contractor Birdair's progress. Crucial site trials are set to start next week after the first consignment of the controversial American-made fabric panels arrived at Thamesport today (Thursday).
Panels used for the trials will be the smallest on the contract, 70m long and weighing only 1t. These are intended for the inner ring of panels at the very apex of the Dome, but the first panels will be tried out at ground level. The checks will be on the unfolding procedure for stiff fabric, which is supplied in 'concertina' form.
The most wind sensitive part of the cladding sequence is the moment when the panel is unfolded on the cable net. Temporary restraints are designed to prevent the panel blowing away before it is tensioned and clipped to the cables. But strong winds could make the operation complex and hazardous.
The maximum permitted wind speed for the highest sections of the cable net erection was 40km/h. A New Millennium Experience Company spokeswoman admitted it had been lucky up to now on the exposed North Greenwich peninsula site.
'Most of the recent high winds were over the Christmas holiday period, so we only lost a couple of days, and we've already caught those up,' she claimed.
But she admitted that work on one section of the net had stopped for three weeks before Christmas following the failure of one of the 36 temporary cable clamps. Friction linings on the clamps had to be replaced and a night shift brought on to make up lost time.
Birdair is hoping the ground level trials will help finalise erection procedures and negotiations with the HSE. The £14M cladding contract is due for completion by late summer.