ENGINEERS WERE this week preparing to start a complex 14 week programme to replace 10 expansion joints and resurface the carriageway of the Runcorn to Widnes Silver Jubilee Bridge.
The bridge will remain open throughout the £2.1M project as work is carried out under temporary bridging units.
These will take traffic across the two biggest expansion joints as they are replaced.
The 40 year old dual carriageway bridge carries 90,000 vehicles per day over the River Mersey between Runcorn and Widnes (NCE 19 February).
The asphalt coated concrete slab deck of the carriageway is supported by longitudinal and transverse steel beams. It is suspended from hangers attached to a pin jointed steel arch truss.
'The two main expansion joints are bespoke and consist of 42 rubber inserts which sit between manganese steel plates, like a sandwich running across the deck, ' said Halton Borough Council bridge engineer Jeff Chrimes.
'These will be replaced with a rubber Maurer D240B expansion joint which is narrower than the existing joint so the edges of the carriageway will also have to be reconstructed, ' he said.
New shock absorbers will be installed beneath the two main expansion joints on the bridge deck to damp the bridge's longitudinal movement.
Contractor Mowlem, working to designs by Mott MacDonald, will also replace a further eight secondary expansion joints and resurface the carriageway.
Heavy congestion on and around the bridge has prompted Halton Borough Council to push for a new crossing close to the existing bridge. It expects the Department for Transport to respond officially to its proposals in December.