Tunnelling underway for new London river crossing

Tunnelling of the new public-transport river crossing at Silvertown is now underway, Transport for London (TfL) and Riverlinx have confirmed.

The 1.4km Silvertown Tunnel will link Newham to the Greenwich Peninsula and provide improved bus links across the Thames when it opens in 2025. 

The tunnel will reduce congestion at the Blackwall Tunnel, provide new cross-river bus links and create a more reliable river crossing for cars, vans and lorries. 

The project is being delivered by the Riverlinx consortium - made up of abrdn, Invesis, Cintra, Macquarie Capital and SK ecoplant - through a design, build, finance, operate and maintain contract. 

Most of the funding is coming from private finance which has been specifically raised for this scheme.

Since the project began in 2020, a huge amount of work has been undertaken to prepare for the start of tunnelling, including the delivery of the launch chamber for the tunnel boring machine (TBM), a conveyor system built to remove excavated materials and also repairs to the river wall made to ensure it is not affected while tunnelling takes place. 

Around 780 people are working full-time on the project, including a number of local apprentices.

Aside from a small section around the tunnel entrances, which will be built using a ‘cut and cover’ technique, the two bores that make up the Silvertown Tunnel are being built using one 82-metre-long TBM, named Jill in honour of Jill Viner, the first female bus driver in London. 

The TBM has a cutter face of 11.91m and is so large, that it had to be transported to the UK in pieces and then assembled within the launch chamber.

Now launched, it will progress under the river at around 10 metres every day and once the first tunnel is completed, will then be turned around to head back to Newham and complete the second tunnel.

Across the course of the project, nearly 600,000 tonnes of material will be excavated and removed from site via barges along the river as part of the project’s wider commitment to keep construction traffic and associated emissions to a minimum. 

More than 150 barges have already been used to deliver or remove materials and waste from site, removing at least 18,000 lorries from the road. 

The excavated materials from tunnelling will be transported along the Thames via barge to a former landfill site in Essex as part of a restoration scheme.

Alongside the tunnelling, Riverlinx will be shortly start work to realign the road network in Newham and Greenwich to link in with the new tunnel. 

From October 17, lane restrictions will take place on the A102 south of the Blackwall Tunnel, with one lane closed in either direction for two weeks, and then the southbound A102 between the Blackwall Tunnel and the slip road off to Blackwall Lane will reduce from three lanes to two from October 31 until summer 2023. 

The start of these works has been timed to tie in with the October school holidays, when traffic levels are usually lower.

TfL and Riverlinx are also actively working on the designs for the walking, cycling and landscaping improvements, which will be delivered around either side of the tunnel entrances. 

Helen Wright, head of the Silvertown Tunnel programme at Transport for London (TfL), said: “The start of tunnelling is a huge step forward for this project and we are committed to working hard to ensure that it is delivered with minimal impact to Londoners. 

“As well as reducing congestion and providing better cross-river bus opportunities, the new tunnel will also help deliver a wide range of local improvements, including dedicated walking and cycling infrastructure and new landscaping. We are working actively on these designs and we hope we can share these with local residents and stakeholders shortly, ahead of starting work on them within the next year.”

Juan Angel Martinez, project director at Riverlinx CJV, added: “I’m very proud of everything this project and our team is delivering, knowing how important it is to us and our supply chain to deliver the programme safely and responsibly, providing sustainable opportunities, career growth and benefits to the local communities and our people. Jill’s journey is an excellent milestone to celebrate.”