Silvertown Tunnel, London

Silvertown Tunnel opened on 7 April 2025, adding 1.4 km of twin two-lane bores under the Thames between Silvertown in Newham and the Greenwich Peninsula, immediately east of the congested Blackwall Tunnel. Transport for London procured it as a design, build, finance and maintain concession worth more than £1 billion, awarded to Riverlinx in November 2019.

Project Scope

One machine bored both tunnels. “Jill,” a Herrenknecht earth pressure balance TBM at 11.87 metres diameter, 82 metres long and about 2,300 tonnes, is the largest TBM ever used in the UK. Rather than buying a second machine, the team drove the first bore, then rotated Jill 180 degrees in a shaft near North Greenwich using a nitrogen skate system and sent her back the other way. The bores are 10.66 metres internally with eight cross passages, and the drive passed through alluvium, London Clay and the Lambeth Group.

Roughly 600,000 cubic metres of excavated material came out, and all of it left by river barge rather than road. Ferrovial has now done five London tunnelling jobs since 2008, after Crossrail, the Northern Line Extension, Thames Tideway and the Heathrow baggage transfer tunnel.

Why It Matters

Rotating a 2,300-tonne machine underground instead of procuring a second one is a real capital saving, and it is the detail worth taking from this job. It costs schedule and it demands a shaft big enough to do it in, which has to be designed in from the start.

The commercial structure is the other half. TfL pays nothing until the tunnel is operational, and tolling went live on both Silvertown and Blackwall at opening, at £4.00 peak and £1.50 off-peak for cars and £10.00 and £5.00 for HGVs. Air quality and climate campaigners opposed the scheme throughout; TfL’s response was a £2 million bus concession fund, £1 million of local business support and resident discounts across Greenwich, Newham and Tower Hamlets. Cross-river bus capacity went from six an hour to at least 40, all zero-emission.

Project Team & Details