The £5 million project to steady the wobble on the Millennium Bridge could be set back unless key partners in the project can agree on who should foot the bill.
As Arup unveiled its solution to the problem, which is already scheduled to take until late summer 2001 to fix, it emerged that there has been no decision on how the costs will be met.The bridge's owner, the London Borough of Southwark, said that it cannot afford to contribute and the remaining partners in the project are in delicate negotiations about how to divide up liability.
Millennium Bridge Trust project director Malcolm Redding refused to say when the discussions would be closed, but admitted that work could not start until the financing is finalised.Arup chairman Bob Emmerson estimated that the money would be in place by the end of the year but refused to rule out drawing funds from outside the original project team of Southwark, the Corporation of London, the Millennium Bridge Trust, Arup and Foster and Partners.
In the meantime, Arup has agreed to finance the £250,000 prototype for the dampers on the bridge, which are being fitted this week.
Dampers will be attached between the existing structure and additional steel bracing, which will transmit the movement of the deck to dampers when the bridge starts to move. These dampers work like pistons in which the piston rods are resisted by a viscous fluid.
Tuned mass dampers, like shock absorbers, will also be fitted to limit any future problems with vertical movement, although this was not a problem when about 100,000 people walked across the bridge on 10 June .
'Together these will reduce the violence of the movement as well as the amount of movement down to a few millimetres, ' said Emmerson.
When the bridge opened it swayed 70mm.
The equipment will mostly be hidden beneath the bridge, but the architects are still considering making it a different colour or shade to the grey of the bridge in order to make the change clear. The discarded option of stiffening the bridge would have meant increasing its stiffness by a factor of nine, and so completely ruining the slender 'blade of light' effect sought by Foster. The full alterations will also require planning consent from the local authorities on either side of the Thames and a decision on this is expected at the end of January.
A contractor for the works will be appointed following an advert in the Official Journal this week. Full remedial work will start following planning permission and will take at least three months.The time taken procuring the unique dampers and then testing the bridge and ensuring the public is confident in the solution will lengthen the time the bridge is closed.
Engineering departments at the universities of Sheffield, Southampton and Imperial College were all drafted in to work on the solution, along with engineers Flint & Neill and WS Atkins.
'The team has done brilliant research, ' said Emmerson.'I don't think the public appreciates the ground-breaking work they have done.'