By lyndamyer
On 28 July 2022, the process of lowering the cutterhead of the tunnel boring machine (TBM) for Transport for London’s Silvertown Tunnel project into its launch chamber was done.
As the largest diameter TBM in the UK, the intended TBM weighs 1,800t and measures 11.91m across.
Following that the Riverlinx construction joint venture (CJV) lowered the first parts of the TBM, the recent landmark achieved by commencing with its shield and the 250t main drive of the machine into place in June.
Using a 600t crawler with a super lift, Riverlinx operatives carried out a four-point lifting and set down operation.
While each lift takes almost two hours to achieve, in order to fully lower all the parts into the launch chamber around 20 lifting operations are required, and work on which was completed in November of last year.
In the summer of the current year, the machine is being assembled within the startup chamber before commissioning and beginning to excavate the 1.4km tunnel.
Elsewhere on the site the conveyor, which will carry tunneling spoil from the chamber to barges to be transported along the river, is approaching completion. The first concrete tunnel rings to be installed as the TBM progresses across the river have also begun arriving on site.
Produced by German manufacturer Herrenknecht, the TBM passed its factory acceptance test in December 2021and it’s been named Jill in recognition of Jill Viner, the first female bus driver to drive a London bus in June 1974.
Connecting North Greenwich and Silvertown, the Silvertown Tunnel is due to be a new twin-lane road tunnel with 1.4km length and beneath the River Thames.
In 2018 the confirmation of constructing this tunnel was delivered to TfL and then this company granted 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.
Following its completion in 2025, the Silvertown Tunnel is going to be considered the first new road crossing east of Tower Bridge since the Dartford Crossing was built over 30 years ago.
