The work is being delivered using ground-freezing and building temporary propping into the cross-passage linings. Ducting which will be located underneath the carriageway in the tunnel is also being installed, so by the end of the year installation of the main road surface in the tunnel will start, allowing for testing and final fit-out of the tunnel systems to commence. 

Work on the cut and cover sections, including the portal entrances, continues along with the new road layouts.

TBM Jill completed the 1.1km drive under the River Thames from Greenwich to Newham in late July, after completing the first bore in February.

The conveyor system has carried more than 780,000 tonnes of spoil via barge so far. The use of river transport to deliver to or from the site has avoided the need for more than 60,000 HGV and other delivery vehicle journeys to date. All TBM bored materials from tunnelling are being transported along the Thames to a former landfill site in Essex as part of a restoration scheme.

In order to begin the second bore northwards to Newham, at Greenwich the TBM was placed on ‘nitrogen skates’ and turned in a rotation chamber.

Spoil from the second tunnel was fed back via the conveyor systems installed in the first tunnel to allow it to be removed by barge from the Newham site. 

Transport for London’s head of the Silvertown Tunnel project, Helen Wright, said completion of tunnelling works was “a massive milestone”, and to complete it in under a year illustrated the project team’s hard work and close collaboration.

“Engineers are working around the clock to deliver this project with minimal impact to those living, working and visiting the local area and we remain committed to delivering a project that supports growth in the local area and provide new public transport connections across the river,” she said.

Riverlinx CJV project director Juan Angel Martinez congratulated everyone involved in delivering the project.

“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,” he said.

The twin-bore Silvertown Tunnel will link Newham on the north of the Thames to the Greenwich Peninsula on the south side, easing congestion at the Blackwall Tunnel. It is scheduled to open in 2025.