The job of carrying out concrete waterproofing work in tunnels is something that will be needed anywhere such structures exist, but London is inevitably where demand is highest.
Quite apart from its Tube system, there are underground sections on London Overground (taken from the former East London line), the DLR, the Elizabeth line, other mainline rail and, of course, road tunnels.
The latter has just seen a huge increase with the opening of the Silvertown Tunnel, supplementing the Blackwall Tunnel as a means of crossing the Thames east of Tower Bridge, where the wider river and shipping have prevented more bridges being built.
It should be a while before any repair work is needed on the brand-new tunnel, whereas the Blackwall Tunnel was constructed 58 years ago. However, it won’t be that long before the next crossing under the Thames is open.
That is because the government recently approved plans for the Lower Thames crossing, the easternmost yet, providing a link between the A2 in Kent and the A13 and M25 in Essex. The connection will include a 4.16-mile tunnel under the Thames.
All of this will ensure more demand for tunnel maintenance in London and the south-east, which could be supplemented further by projects such as an extension to the Bakerloo line.
However, amid all the talk in recent years about ‘levelling up’, will new tunnels be built outside London and the south-east, be it for road or other transport modes?
Nobody is proposing a new underground yet (except for a possible Manchester Metrolink extension), but there have been warnings that the Snake Pass, the A-road that slithers through the Pennines between Manchester and Sheffield, may have to close permanently due to landslides.
Blueprints for a possible road tunnel under the Peak District to connect the two cities have been mooted in the past. The idea has been shelved on cost grounds, but could it now be revived?
This would be a major infrastructure project of considerable cost but huge potential benefit, one that could become far more important if the Snake Pass is closed, leaving the Woodhead Pass as the only direct connection.