Mersey Gateway Bridge MSS Webster In Its Final Position

Southern viaduct to second Mersey crossing complete

Bridge building machine, MSS Webster, has completed its final concrete pour on the £600m Mersey Gateway’s south approach viaduct. The 1,700-tonne machine has been working on the south approach viaduct for around 10 months, slowly creating the reinforced concrete deck expected to carry 60,000 vehicles each day.

Webster is one of two movable scaffolding systems, specially designed and built to construct the curved viaducts leading to the Mersey Gateway Bridge, the centrepiece of the project.

The final pour was a 28-hour operation that saw 1,133 cubic metres of concrete poured into a giant mould to complete the deck of the south approach viaduct. It has now been moved back one span and will slowly be dismantled over the next couple of months before being transported to Bratislava to join its fellow MSS Trinity, which finished some time ago at the Mersey and is now helping to build a new bridge over the River Danube. Remaining concrete will be poured from cranes and other equipment in locations where the MSS moulds are not needed.

Webster is 157m long and 8m high. It is 22m across at its widest point and weighs 1,700 tonnes.

Time-lapse film showing how MSS Webster was built.

In total since it started work MSS Webster has constructed eight spans of the south approach viaduct using 9,205 cubic metres of concrete, equivalent to filling four Olympic-sized swimming pools.

The massive machine has acted as a giant concrete mould, known as ‘formwork’, and needed to be assembled piece by piece. It was initially lifted into place with two giant cranes, one weighing 700 tonnes and one weighing 750 tonnes.

Hugh O’Connor, general manager of Merseylink, said: “To have reached this landmark just 10 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.”

The Merseylink Consortium was appointed by Halton Council in 2014, on a 30-year contract to design, build, finance and operate the project. Its equity partners are Macquarie Capital Group, BBGI, and FCC Construcción. The construction joint venture is made up of Kier Infrastructure & Overseas, Samsung C&T Corporation and FCC Construcción S.A. Emovis will deliver and operate the tolling solution for the consortium through its Merseyflow brand. You can find out more about the tolls at

The new bridge is scheduled to open in autumn 2017.

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The Liverpool City Region keeps growing strength to strength

By Ken

Construction just powered on with this,but seemed to ignore the traffic,resulting in very confusing and sometimes non existant diversion signs at night and day.
They need to be more aware of other road users and it’s not just a case of get it done and s** the rest.
I’ve been to a couple of meetings at which they made presentations etc, telling us how great it’s going to be, but then silence on the Toll charges, I hope this does not impact on the Local economy, otherwise we face about 30 ish miles of tolls to cross the Mersey? Hello Warrington, I hear you have a lovely bridge?

By causal observer

£2 to drive over £2bn worth of infrastructure sounds like a bargain to me. Can’t wait to throw my money at it!

By Jeremy Clarkson

@jezzieClarkson, if you’ve got a fleet of trucks or vans and not in the exemption area, it will be more than £2.00 you will be throwing away? Also this will add to delivery charges, unless you want to drive over and meet the truck yourself?
You don’t work for anyone on the bridge or council do you, you sound to happy to be paying for the privilege to do so, when other bridges in other areas are free. Must have more money than sense, mind you with a name like that?

By causal observer