Tunneling Case Studies

Dubbed ‘London’s Super Sewer’, Thames Tideway Tunnel is the biggest infrastructure project ever undertaken by the UK water industry. Designed to upgrade London’s 150-year-old sewer network, originally built for a population less than half its current size, during heavy rainfall the existing infrastructure was releasing millions of tonnes of untreated raw sewage into the River Thames each year. The new 25 km solution would intercept wastewater and storm water to divert it into plants in a bid to clean up the river.

Catesby Tunnel is an unusually large, disused railway tunnel. Spanning 8.2m (27ft) wide, 7.8m (25ft 6in) high and 2.7km (2,997 yards) in length, it was completed in 1897.

Following a successful first phase in 2018, London Power Tunnels 2 (LPT2) is a project to ‘rewire’ south London. The six-year, £1bn scheme will comprise the construction of 32.5km of 3m-diameter tunnels built deep below the road network between Wimbledon and Crayford to carry high voltage electricity cables.