The Mersey Gateway Project is a major scheme to build a new six lane toll bridge over the River Mersey, to the east of Liverpool. The cable-stay bridge will form the centrepiece of a new and improved high standard link road, 9.5km long, connecting the national motorway network in north Cheshire with Merseyside. The project includes the design, build, finance, operation and maintenance over the next 30 years of the new bridge and approach roads.
RPS and Currie & Brown have acted as Lenders’ Technical Advisors (LTA) for client Macquarie Capital since 2013. This involved due diligence reporting of all the engineering proposals and associated risks on behalf of the major lenders and UK Government Treasury to achieve financial close in March 2014. In line with the construction phase appointment, we monitor and report on the progress of the works against the contract programme and cost plan. This includes updating forecasts of costs to completion and likely completion dates as well as reviewing design or construction quality or technical issues which arise during inspections.
The bridge has a total length of 2.25km, including the north approach viaduct at 700m and the south approach viaduct at 545m, which also crosses the Manchester Ship Canal. The main bridge is a 1km cable-stay bridge, with four spans supported by cables from three pylons. Construction of the three pylons was completed in November 2016, the outer pylons are over 110m in height and the centre pylon is 80m. Construction of the concrete deck is by means of balanced cantilever methods. The approach viaduct decks are constructed using a Moveable Scaffolding System (MSS), a span by span concrete cast in place method with a forward launch procedure, facilitating casting of concrete sections up to 70m in length. Other works include the Astmoor & Bridgewater viaduct with deck construction using precast beams which were cast and shipped from Ireland, along with remedial works to over 10 existing bridges requiring deck waterproofing, bearing replacement and crash protection.
There are eight project milestones, and the first five have been successfully achieved. The next milestone is completion of the main cable-stay bridge deck in June 2017. When complete, the project is expected to help create thousands of new jobs, secure inward investment to the area and deliver important regeneration benefits, including improved public transport links across the River Mersey.