GLASGOW'S TROUBLED Science Centre tower will remain closed for several months more as engineers struggle to find a long term solution to bearing problems at its base.
Testing of the massive thrust bearing that carried the unique £8.5M structure's 450t weight is still continuing at material consultant Stanger Testing Services.
The bearing, which allows the entire 105m tall tower to rotate through 360infinity, was removed by contractor Carillion two months ago after it apparently failed under compressive loads (NCE 11 July. ) Meanwhile the tower, which forms the centrepiece of the Glasgow Science Centre, remains closed, losing its owners several thousand pounds a day in ticket sales.
'Obviously there is pressure to reopen as soon as possible, but the team is looking for a viable long term solution to this complex problem, ' Carillion Scottish operations director David Smith said on Monday.
Carillion is main contractor for the tower.
He added that the radial bearing which sits immediately above the thrust bearing at the bottom of the tower's coneshaped base will be replaced with an identical bearing this week.
But this bearing is only intended to resist wind loads.
'We are reluctant to replace the thrust bearing with an identical component until we fully understand why the failure occurred, ' Smith said.
'It could be that the bearing was subjected to more than just vertical forces. The current series of metallurgical tests should finally determine if it was a manufacturing fault, rather than underspecification.'
Excessive corrosion has been ruled out as a cause for failure.
Water found in the basement pit is now thought to have come from cracks in the seals between the tower and the podium roof that encircles it, caused as the tower sank 15mm.
Smith said one of the options under consideration was switching to a completely different type of bearing.
A spokesman for Swedish bearing manufacturer SKF said there were still 'questions that hadn't been answered' by the investigation to date.