A giant bridge-building machine has finished work on another milestone for the Mersey Gateway project in Widnes.
MSS Trinity’s final concrete pour underway
The bright orange movable scaffolding system (MSS) known as Trinity, which is one of the project’s two bridge-building machines, cast the final central span of the elevated north approach viaduct last week.
Gareth Stuart, project director for the Merseylink consortium, which is building the bridge, said: ‘This is another great achievement for the project.
'We now have the central section of the road deck complete and expect the entire north approach viaduct to be finished within the next couple of months.
Trinity in its final casting position and the Gateway north pylon
‘This key piece of road infrastructure is one of two elevated approach viaducts that will connect the new bridge to the main road networks in Widnes and Runcorn, improving links between the two towns and the wider region.’
The MSS is essentially a giant concrete mould and has constructed 11 road deck spans, creating a seamless structure that sits on top of the supporting bridge piers that stretch across the saltmarsh.
Approximately 14,200 cubic metres of concrete have been used during construction of the central road deck section, which measures a total length of around 715 metres.
The approach viaduct decks are constructed in three phases.
Final concrete pour underway - taken from north bridge deck
Once the central spans have been constructed by the MSS, a deck slab is built on top of the span, and finally the outer deck or ‘wings’ are built by a wing traveller machine to provide the full six-lane width of the approach road.
Trinity, the longest MSS in Europe, was specially made for the Mersey Gateway bridge and will now be dismantled, reused and recycled.
Merseylink said the bridge itself is on schedule to open in autumn 2017.