The Blackwall tunnel will be part-closed for up to five weekends in January and February, drivers were warned on Friday.
Transport for London said the southbound tunnel would be closed to southbound traffic over the weekends of January 13-15, 20-22 and 27-29, as well as on February 10-12 and 24-26.
This is to allow the tunnel to be used by northbound traffic, as the northbound tunnel – the older of the two tunnels, first opened in 1897 – undergoes maintenance work, some of which is linked to the nearby Silvertown tunnel, which is due to open late next year.
Southbound motorists will have to seek an alternative route – meaning many will have to divert via the M25 Dartford Crossing. Other alternatives include Tower Bridge and the Rotherhithe tunnel, though larger vehicles face height and weight restrictions.
Drivers of HGVs, as well as vans more than 2m in height or weighing more than two tonnes, are advised to consider routes away from central London across each weekend.
On each weekend, the closures will start at 00:01 on the Saturday morning, with the tunnel reopened by 5am on the Monday morning at the latest.
The work at Blackwall involves drainage and gantry installation works on the northbound Blackwall Tunnel approach by Silvertown contractor Riverlinx CJV.
The proposed closure on the weekend of January 27-29 is a “contingency” in case not all the work planned for the two earlier weekend closures can be completed – meaning it may not be enforced if sufficient progress has been made.
During the weekend of February 24-26, northbound traffic will also be diverted from the A102 via Millennium Way to the Blackwall tunnel entrance from 10pm until 8am to allow for additional works to install new gantries across all lanes of the A102.
Carl Eddleston, director of network management and resilience at TfL, said: “The Blackwall Tunnel is used by tens of thousands of vehicles every day and we appreciate that these planned weekend works will have an impact on some drivers.
“With less than 18 months until the new Silvertown Tunnel opens, we are working with Riverlinx CJV to prepare the northbound carriageway, and have worked hard to try and limit the potential disruption these will cause, such as ensuring a northbound route can be maintained throughout these closures.”
Bus route 108 will be temporarily split and terminate at Canning Town station and North Greenwich, with customers using the Jubilee line to cross the river to complete their journeys.
Tolls will be introduced on the Blackwall tunnel next year when the Silvertown tunnel opens - and a return trip could cost more than £10.
Drivers will have to pay the same levy to use either tunnel. Mayor Sadiq Khan and the TfL board is due to decide this autumn on the scale of the charges.
