Tunnelling work on the two new road tunnels under the Thames in east London has been completed, and the first photos inside have been released by the company building the tunnels.
Tunnelling breakthrough by the TBM (c) RiverLinx
The tunnel boring machine (TBM), named in honour of Jill Viner, the first female bus driver in London, completed the 1.1km drive from Greenwich to Newham late last month, after completing the first bore in February 2023, meaning that all main tunnelling works were completed in less than a year.
Aside from a small section around the tunnel entrances being built using a ‘cut and cover’ technique, the two bores that make up the Silvertown Tunnel have been built using one 82 metre-long, 11.9 metre-diameter TBM. During tunnelling of the second bore, the TBM averaged around 22 metres a day as it worked its way under the river from Newham to Greenwich.
Inside the new road tunnel (c) RiverLinx
The conveyor system, built on the north side of the Thames to remove TBM bored materials, has helped transport more than 780,000 tonnes of spoil via barge so far. All of the TBM bored materials from tunnelling are being transported along the Thames to a former landfill site in Essex as part of a restoration scheme.
The tunnelling of the second bore follows the successful rotation of the TBM in Greenwich, where it was placed on ‘nitrogen skates’ within a rotation chamber and turned around. Spoil from the second tunnel was fed back via the conveyor systems installed within the first tunnel to allow it to be removed by barge from the Newham site.
With the main tunnelling work completed, the company building the tunnel, RiverLinx is now excavating the eight cross-passages which will run between the tunnels and help provide a safe route out of the tunnel should it be required. These will be dug out by first freezing the ground and building the temporary propping into the cross-passage linings. Ducting which will be located underneath the carriageway within the tunnel is also currently being installed, so that by the end of the year the main road surface within the tunnel can start to be installed to allow for testing and final fitout of the tunnel systems to commence.
Work on the ‘cut and cover’ sections of the Silvertown tunnel, which includes the portal entrances, continue to be delivered, as well as the new road layout into the Tidal Basin roundabout in Newham, and link roads into the A2 south of the Blackwall Tunnel.
The tunnel is due to open to road traffic in spring 2025.
The south portal into the tunnel (c) RiverLinx
As an experienced mathematical modeller, I hope TfL’s modelling of traffic flows, when the Silvertown Tunnel opens and the Blackwall Tunnel is charged is closer to what happens, than their pathetic effort of calculation of bus passengers on the 21/43/76/141 bus corridor North through the City via London Bridge, Bank and Old Street, on the opening of the Bank upgrade and the Elizabeth Line.
I suspect that trucks could use Silvertown rather than the Dartford Crossing at times and whole sections of North London could be jammed solid, as trucks aim to reach the M4 and M1.
Silvertown should not be opened until after the Lower Thames Crossing is completed and fully open.
Have they even started construction on the lower Thames crossing? Even if they have it’s not due to open for another 8 years at least.
Meanwhile you just want to leave an expensive piece of infrastructure idle not earning any money to repay the loans taken out to build it as well as not relieving traffic using the Blackwall Tunnel?
They could have halved the traffic at Blackwall by lifting tolls at Dartford.
Now you know that lots of people will try to go to Rotherhithe….