Year
2020-2025Duration
5 yearsCost
£1.2 billionLocation
United KingdomProject achievements
Economy boosted
Supporting the creation of thousands of new jobs
Environment benefitted
Reduces congestion and subsequent emissions from idling vehicles
Greater accessibility
Features new cycle link and two-way footbridge with step-free access
First new road crossing east of Tower Bridge in over 30 years
The Silvertown Tunnel – which opened on 7 April 2025 – is a 0.9mi (1.45km) long twin-bore tunnel passing underneath the River Thames in East London, connecting Silvertown with North Greenwich.
It was built to help alleviate congestion in the area, particularly through Blackwall Tunnel, which is currently one of two fixed routes between the Dartford Crossing and Tower Bridge.
It also aims to improve cross-river public transport options by allowing new zero-emission bus routes to cross the Thames.
Blackwall Tunnel originally opened in 1897. Due to its narrow design, it has become increasingly congested and inefficient, leading to delays, collisions and limited capacity for public transport as only single-deck buses can use the tunnel.
Silvertown Tunnel, which was created with the largest tunnel boring machine (TBM) in the UK, features two lanes in each direction, one dedicated for double-decker buses, coaches, and heavy goods vehicles.
The tunnel increases the number of buses crossing the river from six to 21 per hour.
New bus routes – including the Superloop 4 (SL4) between Canary Wharf and Grove Park, and those serving Greenwich, Newham and Tower Hamlets – also started on the tunnel's opening day and will be free for the first year.
Road user charging at the new Silvertown and existing Blackwall Tunnels will help to manage traffic levels.
The project also facilitated improvements for pedestrians and cyclists, as it includes a step-free access footbridge allowing people to cross from the A102 to the Thames Path safely, alongside a range of new walking and cycling routes around the tunnel portal.
The new tunnel, along with the initial user charges, discounts and exemptions, will support growth in the local area and provide new public transport connections across the river.
These measures will also help manage traffic demand as well as the environmental impacts, and ensure the new tunnel delivers on its objectives of reducing traffic congestion and providing resilience at the Blackwall Tunnel, while ensuring we support local residents on low income, small businesses, sole traders and local charities.
Stuart Harvey, chief capital officer at Transport for London
Did you know …
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The TBM on the project has been named Jill in honour of Jill Viner, who in 1974 was the first woman to drive a London bus.
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It’s estimated that more than 100 apprentices were trained throughout the project.
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A discount for using the tunnel will be available to low-income residents in the boroughs of Greenwich, Newham and Tower Hamlets as well as support for small local businesses.
How the Silvertown Tunnel was built
The tunnel was built using a TBM. Construction started in 2020, with worksites set up in Newham and Greenwich.
The site in Newham was the launching point for the TBM, where the machine started to dig out the southbound tunnel. To do so, the river wall had to be strengthened, which also improved flood defences.
Geotechnical surveys and in-river ground investigations have taken place.
A conveyor system was set up to remove excavated materials from the site via barges along the River Thames – this also helped to reduce the project’s emissions and improve road safety in London, as it removed thousands of lorries from local roads.
A rotation chamber in Greenwich was excavated to receive the TBM. Once it broke through, the TBM turned 180 degrees to dig the northbound tunnel. A retrieval chamber was created in Newham – this is where the machine was disassembled once it’d done its job!
The walking, cycling and landscaping improvements were done as part of the wider highway works at the surface to tie the new tunnel into the existing road network.
The team also constructed new buildings above the tunnel portals which house operation and maintenance facilities.
Difference the project will make
The tunnel will relieve pressure on the existing Blackwall Tunnel, which is the only strategic road crossing of the River Thames in east London, where much of the city’s growth in population and jobs is expected to take place.
By adding another crossing at this location, journey times across Blackwall Tunnel are expected to be 20 minutes faster.
Transport for London (TfL) modelling has also shown that congestion at the Blackwall Tunnel will be effectively eliminated during peak hours, which will reduce emissions from idling cars stuck in traffic.
Furthermore, user charges across Blackwall Tunnel and Silvertown Tunnel will help ensure that traffic levels across the local area are effectively managed. It also helps discourage unnecessary car journeys.
A range of benefits for local residents will encourage greater public transport use – further reducing emissions in the area.
For cyclists, who can't ride through the tunnel for safety reasons, Transport for London (TfL) has invested in a novel solution: a dedicated 'bike bus' service.
Operating five times per hour between 6.30am and 9.30pm, this free zero-emission shuttle service will allow cyclists to transport their bikes across the river.
With the introduction of the tunnel, 20% of businesses in the area have said they’ll be able to take on more staff supporting the creation of thousands of new jobs.
The project is the first step in major regeneration planned on both sides of the river around the Greenwich Peninsula and the Silvertown area of the Royal Docks.
As part of this, the project has cleared many of the existing industrial sites, constructed new flood defences, and creating new habitats to ensure a net increase in biodiversity across the area.
Now the tunnel construction is complete, the construction site will be released to enable the development of new riverfront neighbourhoods.
Project milestones
Main construction starts
TBM ‘Jill’ assembled
Tunnelling begins southbound, towards Greenwich
TBM turned around at Greenwich, tunnelling begins northwards
Traffic and environmental assessments take place to inform user charges. Cross-river bus networks proposals developed
User charges finalised and account system delivered
Silvertown Tunnel opens, including road user charging system and start of new bus routes
People who made it happen
- Riverlinx CJV (Construction Joint Venture) made up of BAM Nuttall, Ferrovial Construction and SK ecoplant.
- Transport for London
