The frontrunner to build the £1bn Silvertown Tunnel in East London failed to even make the shortlist, New Civil Engineer can reveal.
A Bouygues/Bam Nuttall joint venture was hotly tipped to win the project that demands very complex tunnelling in a confined urban area. It was thought that Bouygues’ experience in building the 1.2km Port of Miami tunnel in a very similar environment made it a hot favourite to land the job.
But it is understood that the Bouygues/Bam Nuttall JV has fallen at the first hurdle by failing to make the shortlist.
Three bidders – Ferrovial-owned Cintra Global, Hochtief PPP Solutions and Strabag/Skanska remain in the hunt.
Transport for London (TfL) is looking for a contractor to design, construct, finance and maintain the project, which comprises a 1km, twin-bore road tunnel to be constructed east of the Blackwall Tunnel. Tolls will be used to manage demand and help fund the scheme.
Teams submitted prequalification documents last November. A planning inquiry into the proposal will end next month and has to report back to transport secretary Chris Grayling by July. If Grayling approves the scheme, a decision is expected in the Autumn, it is expected that a contract would be awarded later this year with construction slated to start in 2019 for completion in 2023.
The Ferrovial-owned Cintra Global bid is being supported by Arup, Cowi and Ayesa.
Hochtief’s bid is actually a joint venture bringing in sister company Iridiium and John Laing Infrastructure Fund, with actual construction work planned to be subcontracted to Hochtief’s UK arm and Spanish sister firm Dragados.
Shortlisted firms will now work up Atkins’ reference design and seek improvements.
Currently the tunnel project is proposed to comprise two 11.45m internal diameter bores, each approximately 1km long, with two traffic lanes per bore and connecting cross-passages.
Cut and cover approaches at Greenwich and Silvertown are each approximately 200m long.
Each approach will include a tunnel boring machine (TBM) chamber at the interface with the bored tunnel to facilitate its construction.
The major engineering challenge for the project is the fact that it will be built in the area that historically was occupied by heavy industry, and underground remnants of redundant and demolished structures are still are present. In recent years, new infrastructure such as the Docklands Light Railway (DLR), Woolwich branch viaduct, and Emirates Air Line (EAL) were constructed close to the proposed tunnel route.
A further challenge is maximising the ground cover between the tunnel crowns and the Thames riverbed, while maintaining the tunnel’s vertical gradient at 4%.