The COWI-designed Mersey Gateway Bridge opened to traffic this morning.
The three-pylon cable-stayed bridge is a landmark structure recognisable throughout the North West and beyond, providing a much-needed new crossing of the river and acting as a catalyst for growth in the region. As well as the bridge, the project includes new highways and junctions.
The design team
COWI led the Mersey Gateway Design Joint Venture – alongside AECOM, Fhecor and Eptisa, with architectural support by Dissing+Weitling – which was engaged by the Merseylink Civil Contractors to deliver the design of the £1.86bn scheme. COWI designed the bridge while AECOM led the design of the landside works including 7km of new roads.
COWI Project Director Paul Sanders commented: “It was fantastic to see the bridge open to the public this morning, marking the culmination of three and a half years of hard work. We developed the bridge’s design around rapid construction cycles and long term durability and I’m extremely proud of the role our engineers played in delivering the project on schedule.”
Dave Beddell, AECOM Europe Sector Leader – Highways, commented: “We are proud of our role in helping to deliver this critical piece of infrastructure. Through collaboration and an unrelenting focus on delivering a safe and efficient highway design, whilst maintaining wild-life habitats within the estuary corridor, the new Mersey Gateway Crossing will significantly reduce network congestion and improve connectivity for businesses and communities alike.”
About the bridge
The cable-stayed bridge is 1km long and made predominantly of concrete and reinforced steel. The south pylon is the tallest at 125m, followed by the north (110m) and central (80m) pylons. The deck is roughly 25m above the river bed and around 2.2km long, including the approach viaducts.
The main bridge deck is constructed from pre-stressed and reinforced concrete suspended from the pylons via high strength steel cable stays. There are 146 cables in total, spread to reflect the heights of the pylons: 62 on the south, 54 on the north and 30 on the central pylon.
Designed for construction
Structural and geotechnical engineers from COWI worked closely with the Merseylink Civil Contractors, Merseylink Ltd (the DBFO consortium) and Halton Borough Council to develop a bridge design that could be built quickly and operated and maintained as cost effectively as possible.
The decks of the approach viaducts were constructed using two 1700 tonne, 157m long self-propelled launching gantries (movable scaffolding systems) enabling rapid and safe construction of a complete 70m long span in a single pour.
On the cable-stayed bridge, six smaller gantries (form travellers) were used to cast the deck in 6m long segments in a typical cycle of just five days.
The design for the bridge was selected from a wide range of options to maximise benefits for users and the local community while minimising the environmental impact on the estuary and its surrounding environment.
About COWI in the UK
Flint & Neill and Donaldson Associates have joined together to form COWI in the UK. In the UK, COWI provides civil, structural and geotechnical engineering services, specialising in the design and maintenance of bridges, tunnels, and marine structures.
COWI is a leading consulting group that creates value for customers, people and society through our unique 360° approach. Based on our world-class competencies within engineering, economics and environmental science, we tackle challenges from many vantage points to create coherent solutions for our customers – and thereby sustainable and coherent societies in the world.
AECOM is built to deliver a better world. We design, build, finance and operate infrastructure assets for governments, businesses and organizations in more than 150 countries. As a fully integrated firm, we connect knowledge and experience across our global network of experts to help client s solve their most complex challenges. From high-performance buildings and infrastructure, to resilient communities and environments, to stable and secure nations, our work is transformative, differentiated and vital. A Fortune 500 firm, AECOM had revenue of approximately $17.4 billion during fiscal year 2016. See how we deliver what others can only imagine at aecom.com and @AECOM.
About the Mersey Gateway Project
The Mersey Gateway Project is one of the largest infrastructure initiatives in the UK. It has been identified as one of the UK government’s Top 40 priority projects in the National Infrastructure Plan and it has been recognised by KPMG as one of the ‘Top 100 infrastructure projects around the globe’.
Its features include:
– a 1,000m long cable stay bridge consisting of four spans supported from three towers in the estuary;
– a unique design where the 80m high central tower is shorter than the two outer towers, which are 110m (north tower) and 125m (south tower);
– a total length (including the bridge and approach viaducts) of 2.2km;
– a deck carrying six lanes of traffic (three in each direction) with a speed limit of 60mph;
– supporting piers carrying it across the approach viaducts; and
– a curved approach at each end of the bridge giving varying views of its unique design and maximising its visual impact.
You can find out more about the project at www.merseygateway.co.uk.
Emovis is delivering and will operate the tolling solution for the consortium through its merseyflow brand. You can register now for tolls and discounts at www.merseyflow.co.uk.