Final concrete pour on Mersey Gatewaynews
27th July 2017
The massive 'Meccano set' that has been working for the past ten months on the south approach viaduct to the new Mersey Gateway poured its final concrete in late June, completing the reinforced concrete deck that will ultimately carry an estimated 60,000 road vehicles per day.
Movable Scaffolding System (MSS) Webster weighs in at 1,700 tonnes and is described by the Mersey Gateway Project as being "like a giant Meccano set", constructed over the viaduct and capable of pouring the concrete deck as it moves along the road's future route.
Two of the structures - MSS Webster and its partner MSS Trinity - were designed and built especially for this project and have been working on construction of the centrepiece Mersey Gateway Bridge and its curved, elevated approach roads, which are due to open in the autumn of this year.
In the final phase, MSS Webster poured 1,133 cubic metres of concrete into a massive mould, completing the south approach viaduct deck in a single pour lasting for 28 hours, before being moved back to a previously completed span for dismantling.
Like MSS Trinity, it will now be shipped to Bratislava - following a dismantling process that will in itself take several months - where the pair will go back to work building a new bridge deck to span the River Danube.
MSS Webster serves as the formwork for the concrete it pours, measuring some 22 metres wide, eight metres high and 157 metres long; it has been used to complete eight individual spans of the viaduct, each equivalent to half of an Olympic-sized swimming pool in the volume of concrete used, for a total of nearly 10,000 cubic metres.
Hugh O'Connor, general manager for Merseylink, said: "To have reached this landmark just ten months after building Webster is great news for the project.
"The viaducts on either side of the river are huge structures in themselves, with the south approach viaduct requiring a considerable degree of engineering and construction skill to build, as well as using a huge amount of material. This final pour on the south approach viaduct means we're getting closer and closer to completing this iconic bridge."
Written by Ian Johnson