Work is in full swing above and below ground building London’s super sewer but, in the depths of the River Thames, another team has been grafting in the river to help build London’s super sewer.  

A group of divers has completed more than 500 dives across the central sites for the Thames Tideway Tunnel, under construction to help stop millions of tonnes of sewage overflowing into the River Thames. 

Working at sites in Blackfriars, Chelsea and Victoria Embankment, their tasks include welding and mud-sucking, supporting the construction of cofferdams out into the River Thames. These new pieces of land will allow shafts to be built to connect the existing Victorian sewers into the new, 25km Thames Tideway Tunnel. 

Professional diver, Adam Blagg, said: “You get a chance to work in some places that no one else has ever seen or touched. Visibility is zero but you can hear all sorts of different noises, including the tube.” 

Alex Wood, Dive Supervisor from subcontractor DiveCo, said: “The Thames is very tidal, which brings its own challenges: it can be very difficult diving in strong tides. Here in London, because we’re only about eight metres deep, we can dive for up to four hours and it varies massively what we do. It’s been a really interesting project, we’ve tried to adapt to all the challenges it’s presented us.” 

Blackfriars Project Manager, Peter Rouzel, said: “There are a lot of complex activities required to deliver major construction projects, and diving operations are not necessarily an activity you’d think of, but the team here are absolutely pivotal to all the work we are doing at Blackfriars. Their skills and experience in building a project of this scale in the River Thames are invaluable.”

The Thames Tideway Tunnel is a 25km super sewer from west to east London, which will help tackle the tens of millions of tonnes of sewage that pours into the River Thames each year.

Work is currently underway at 24 sites across London, and is due for completion in 2025*.

*This article has been amended to reflect the project's updated completion date following an analysis of the impacts of the pandemic.