Jill, the 11.9m diameter Herrenknecht TBM delivering the Silvertown Tunnel in east London, has now completed work on the second bore, meaning that all main tunnelling work on the UK capital’s new river crossing is completed.
The TBM completed the 1.1km drive from Greenwich to Newham in late July 2023, after completing the first bore in February 2023, meaning that all main tunnelling works were completed in less than a year. During tunnelling of the second bore, the TBM averaged around 22m a day.
The tunnelling of the second bore follows the successful rotation of the TBM in Greenwich, where it was placed on ‘nitrogen skates’ within a rotation chamber and turned around in a highly innovative and complex process. Spoil from the second tunnel was fed back via the conveyor systems installed within the first tunnel to allow it to be removed by barge from the Newham site.
With the main tunnelling work completed, eight cross-passages are being constructed between the tunnels which will provide a safe route out of the tunnel should it be required. These will be delivered using ground-freezing and building the temporary propping into the cross-passage linings. Ducting which will be located underneath the carriageway within the tunnel is also currently being installed, so that by the end of the year the main road surface within the tunnel can start to be installed to allow for testing and final fitout of the tunnel systems to commence.
Work on the ‘cut and cover’ sections of the Silvertown tunnel, which includes the portal entrances, continue to be delivered, as well as the new road layout into the Tidal Basin roundabout in Newham, and link roads into the A2 south of the Blackwall Tunnel.
Juan Angel Martinez, Project Director at Riverlinx CJV said: “This is such an important milestone for the Silvertown Tunnel construction and I would like to congratulate everyone involved in delivering it. The technical expertise, focus and collaboration of this team have enabled us to safely complete the main tunnel drive to programme. The CJV formed by Ferrovial Construction, Bam Nuttall and SK Ecoplant has done a fantastic job implementing innovative and pioneering solutions for the UK such as the TBM rotation and frozen cross-passages. Working together with TfL as well as our many local stakeholders, Riverlinx is now focusing on the next stages of construction to successfully deliver this vital piece of infrastructure for London.”
The project is being delivered through a £1bn design, build, finance, operate and maintain contract, with the vast majority of the funding for the new tunnel is coming from private finance which has been specifically raised for the scheme.
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