1963. The Thelwall Viaduct opened to carry the M6 motorway over the Manchester ship canal and River Mersey.
1996. Viaduct refurbished at cost of £27M by contractor Amec and consultant Pell Frischmann to support higher traffic loads. Corroded expansion joints removed and number of joints reduced overall. All bearings replaced.
1996. A new six-lane viaduct is built by Tarmac next to the 1960s viaduct, costing £24M.
July 2002. Routine inspection reveals one of the largest roller bearings had split in two and three others showing signs of deterioration at pier V. All four roller bearings replaced.
December 2002. Four rocker bearings also replaced at pier V.
January - May 2003. Eight faulty bearings identified in random locations. These are removed and deck is temporarily supported.
Replaced in August.
July 2003. Tests reveal that all 148 roller bearings must be replaced at a cost of £42M.
September 2004. Extra strengthening work to cost £10M Spring 2005. Viaduct expected to reopen to traffic.