Tunnelling underway for new river crossing at Silvertown

7 Sep 2022 11:20 AM

New public-transport focused tunnel will reduce congestion and improve reliability and resilience at Blackwall Tunnel

Tunnelling of the new public-transport focused 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. By reducing congestion at the Blackwall Tunnel, providing new cross-river bus links and creating a more reliable river crossing for cars, vans and lorries, it will support economic growth across east and southeast London. It will also provide better access to new job opportunities and support new housing and business developments across the wider area.

The project is being delivered by the Riverlinx consortium, which is made up of abrdn, Invesis, Cintra, Macquarie Capital and SK ecoplant, through a design, build, finance, operate and maintain contract. The vast majority of the funding is coming from private finance which has been specifically raised for this scheme.

Since construction work on the project began in 2020, a huge amount of work has been delivered 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 who are benefiting from working on a major construction project in their area.

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 commencing work to realign the road network in Newham and Greenwich to link in with the new tunnel. From 17 October, 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 31 October 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. These will see new dedicated cycleways and footways, as well as 'shared space' and new public realm installed across Tidal Basin Road roundabout, which will link in with wider improvements planned by Newham Council across the Royal Docks area. The proposed landscaping around the tunnel entrances, as well as a green roof on both tunnel portal buildings, will also form part of the scheme's commitment to environmental improvements and promoting biodiversity across the wider area.

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, said: "This really is a terrific achievement which has only been made possible by the excellent effort and collaboration of everyone involved. 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."

To follow progress of the TBM under the Thames, please visit www.riverlinx.co.uk For more information about the Silvertown Tunnel, please visit www.tfl.gov.uk/silvertown-tunnel

Notes to editors

Throughout the development of the Silvertown Tunnel, the project has been subject to a rigorous and transparent process to demonstrate it is the right solution and that its impacts have been properly assessed and mitigated.

All vehicles working or delivering to the construction sites meet Euro VI standard and Riverlinx have adopted a Stage IV or better policy for Non-Road-Mobile Machinery (NRMM) across the project, including using innovative hybrid technology. This means that they meet or exceed the requirements of the GLA's NRMM Low Emission Zone. All construction vehicles will also comply with the latest safety standards in support of our Vision Zero ambitions.

Once the Silvertown Tunnel is open, the total number of buses running through both Blackwall and Silvertown Tunnels will increase, with TfL committed to running at least 20 zero-emission buses per hour through the tunnels at peak times. TfL expects the overall provision of buses through the area could further increase to 37 buses per hour over time as new developments, including at the Royal Docks and Greenwich Peninsula, are completed during the next decade.

User charging at the Blackwall and Silvertown Tunnels, which will commence once the Silvertown Tunnel is complete, alongside the new zero-emission bus network, will help to manage traffic levels and encourage people to switch their journeys to public transport where possible. No user charges have been finalised yet and any times and costs within the submission are indicative to allow for approval to be obtained. The final charges will be announced ahead of the Silvertown Tunnel opening in 2025 once further modelling, including assessments on concessions, are complete.

TfL is legally committed to delivering a wide range of improvements and measures to reduce the impact of the new tunnel and support the wider local area. These include:

  • £1m worth of support for local businesses to help them adapt to the user charge when the Silvertown Tunnel is operational. This could include helping businesses with staff travel planning or funding potential infrastructure such as cycle racks and electric vehicle charging points
  • A user-charging discount to specifically help low-income residents in the host boroughs of Greenwich, Newham and Tower Hamlets. This could look similar to the existing TfL Bus & Tram Travelcard which offers a 50 per cent discount on public transport for those who receive certain state benefits.
  • £2m in bus concessions for local residents to help promote the new cross-river bus services which will run through the tunnel, as well as supporting them to move away from unnecessary private car use. TfL will also enhance river crossing facilities for cyclists and pedestrians across the local area

Both the tunnel and the surrounding area also fall within the Ultra Low Emission Zone, and since December 2020, TfL has undertaken a comprehensive programme of air quality monitoring to ensure the impacts of the Silvertown Tunnel are fully understood, and to support the delivery of the overall air quality improvement expected as a result of the scheme. 38 diffusion tubes and three continuous monitoring stations recording nitrogen dioxide (NO2) levels have been installed across five boroughs, and TfL has also installed a continuous PM2.5 monitor in Newham, to complement existing local authority monitoring within Greenwich and Tower Hamlets.

Data collected from the continuous monitoring stations is available on the London Air Quality Network (https://www.londonair.org.uk/) and support wider AQ initiatives across the capital. Air quality updates are also provided via the Silvertown Tunnel Implementation Group, with TfL's first report on air quality monitoring being published shortly.