News

Jul 25, 2023

Silvertown Tunnel: Final tunnel boring machine assembly begins

The first parts of the tunnel boring machine for Transport for London’s

The first parts of the tunnel boring machine for Transport for London's Silvertown Tunnel project have been lowered into its launch chamber.

Earlier this month, the Riverlinx construction joint venture (CJV) achieved another key milestone on the Silverton Tunnel scheme.

The first parts of the project's tunnel boring machine (TBM) were lowered into place, starting with its shield and followed by the 250t main drive of the machine.

Using a 600t crawler with a super lift, Riverlinx operatives carried out a four-point lifting and set down operation.

Each lift takes approximately two hours to achieve. Around 20 lifting operations will be required to fully lower all the parts into the launch chamber, work on which was completed in November of last year.

The Silvertown Tunnel TBM was built by German manufacturer Herrenknecht and passed its factory acceptance test in December 2021. It was then delivered to Newham in London in pieces, while the site was prepared ahead of the final assembly within the launch chamber.

Last month, the Riverlinx team undertook a tandem lifting operation of the tunnel eye for the launch chamber.

The machine has a diameter of 11.91m – the largest to be used in the UK – and its front section alone weighs 1,200t.

Throughout the next month, the Silvertown tunnelling team will continue to lift parts into the launch chamber before final sign-off and start of tunnelling later this summer. The TBM will initally start to dig out the southbound tunnel towards Greenwich.

As is traditional in tunnelling projects, Riverlinx has given its TBM a female name in honour of someone who has made an outstanding contribution to her sector or community.

Following an internal competition among Transport for London (TfL) and Riverlinx employees, the name Jill was chosen for the TBM. This is in honour of Jill Viner - the first female bus driver to drive a London bus in June 1974.

Riverlinx and TfL said that Viner is a fitting choice given how the tunnel will create new cross-river bus opportunities and her contribution to equality within the transport industry.

Riverlinx CJV project director Juan Angel Martinez said: "Tradition states that the machines must be officially named before they can start work – and, as the patron saint of miners and tunnellers is Saint Barbara, they are given female names; our TBM will be named ‘Jill’."

TfL head of delivery for Silvertown Tunnel Helen Wright added: "The start of final assembly of the TBM within the launch chamber is a major milestone for the Silvertown Tunnel project as we prepare for the start of tunnelling later this year."

The Silvertown Tunnel will be a new 1.4km twin lane road tunnel under the River Thames, linking North Greenwich and Silvertown.

TfL received permission for the tunnel in May 2018. It then awarded the Silvertown Tunnel design, build, financing, operations and maintenance contract to the Riverlinx special purpose vehicle (SPV) in 2019.

The SPV comprises Ferrovial subsidiary Cintra, Bam PPP PGGM, Macquarie Capital, SK E+C and Aberdeen Standard Investments. Construction is being delivered by the Riverlinx CJV, which includes Bam Nuttall , Ferrovial Construction and SK Ecoplant.

When completed in 2025, the Silvertown Tunnel will be the first new road crossing east of Tower Bridge since the Dartford Crossing was built over 30 years ago.

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