The Blackwall Tunnel will close across another two weekends this summer, TfL has confirmed.
The major east London tunnel is to close this weekend between August 17 to 19 so work can be carried out on the new £2billion Silvertown Tunnel in east London, which is set to open next year.
TfL has now announced it will also shut across the weekend of September 7 to 9 for further work.
The closures “will allow for the final road configuration to be implemented, as well as road resurfacing and safety barrier works to be carried out” in the Silvertown Tunnel, says TfL.
It will also use the closure to carry out works within and around the Blackwall Tunnel.
Across both weekends, the tunnel will be closed for southbound traffic and drivers will need to take alternative routes.
Northbound traffic will not be affected.
The weekend closures will start just after midnight on the Saturday mornings and will continue until 5am on the Monday at the latest, says TfL.
It advises drivers to plan their routes in advance, checking potential restrictions on other routes, and said they should consider using other modes of transport where possible.
“Roads and alternative river crossings in east and central London are expected to be extremely busy with traffic around Rotherhithe Tunnel and along the A13 Commercial Road between Canning Town and Whitechapel heavier than normal over the weekends due to the closures,” it said.
“The Woolwich Ferry, which now departs every fifteen minutes, seven days a week, will be in operation across the weekends.
“Where possible, people should consider using public transport or walking and cycling via other river crossings to complete their journey.
“Drivers of HGVs, as well as vans more than two metres in height or weighing more than two tonnes, are advised to consider routes away from central London across the weekends where possible.”
The route 108 - the only bus route that operates through the Blackwall Tunnel - will be split in two, operating between both Lewisham and North Greenwich and between Canning Town and Stratford.
Customers are advised to then change onto the Jubilee line to cross the river to complete their journeys. TfL says they will then be refunded for the Tube section of their journey.
The Victorian-era Blackwall Tunnel suffers from frequent closures - more than 700 times a year - which result in large tailbacks, poor air quality and millions of hours lost due to drivers being trapped in traffic.
Plans for the Silvertown Tunnel were first developed in 2012, to help address the chronic congestion around the Blackwall Tunnel.
Linking Silvertown in east London to the Greenwich Peninsula, it is aimed at reducing journey times and helping manage air pollution.
Motorists will pay tolls to use it, and when it opens new tolls will also be introduced for those using the Blackwall Tunnel.
The new tunnel will also allow TfL to increase buses across the river in the area, from five to 21 zero-emission buses an hour in each direction during peak times.
TfL says works on the new Silvertown Tunnel “continues to progress well”.
“Both of the 1.1km tunnels have been fully tunnelled and safety critical equipment now being installed,” it said.
“The final road surface is being installed within the tunnels and approach roads, which will allow for critical testing and assurance work to take place ahead of opening.
“Work is also nearing completion on the new road layout around Tidal Basin Roundabout in Newham.”
TfL spokesperson Nick Fairholme said: “We are now in the final phase of works to complete the Silvertown Tunnel and these closures will help us to start to get the tunnel ready to open.
“We appreciate that these planned weekend works will have an impact on some drivers and are doing everything we can to limit potential disruption - including ensuring a northbound route through the Blackwall Tunnel is maintained throughout.”