BEARING REPLACEMENT has begun on Glasgow's controversial Science Centre Tower, main contractor Carillion has confirmed.
Subcontractor Calley Ocean Systems began jacking the 450t, 105m high structure off its temporary supports on 19 August so that a new bearing could be installed.
The bearing replaces a Swedish made thrust bearing which failed soon after the troubled $13.5M structure opened last year.
It will take the entire weight of the tower and is supposed to allow the whole structure to be rotated through 360infinity so that its high level viewing platform always faces into the prevailing wind.
The new unit is a 550mm diameter, 280mm thick plain bearing - basically a steel disc.
It has a concave 'dimple' in its upper flat surface to mate with the rounded point of the inverted steel cone which in turn supports the tower.
It was manufactured in Germany by PAN Metallgesellschaft.
Ahead of installation, support joists and winches will be installed in the 15m deep bearing pit once the tower has been raised 5mm.
Carillion expected the operation to take no more than three weeks.
A Carillion spokeswoman also confirmed that the bearing support stool in the pit would have to be replaced with a new structure to accommodate the new, larger bearing.