Uponor’s Weholite technology was the key solution in a unique project in London, where the Lee Tunnel and Thames Tideway tunnel have the task of capturing an average of 39 million tonnes of sewage a year from the 35 most polluting combined sewer overflows (CSOs). An upgraded pipeline system was designed to reduce the number of overflows – and their environmental impact – from the sewers and treatment systems serving London. A particular aim is to limit pollution from the sewers and treatment systems connected to the Beckton and Crossness sewage treatment works.
London’s globally admired sewage system was created in the Victorian era. This system now faces the challenges of ongoing urbanisation and ever-growing sewer discharges.
Construction work on the Lee Tunnel began in 2010 and was completed by the end of 2015. In this 4.2 billion pound project, a Weholite culvert served as the final discharge point of the tunnel, transferring the sewer overflow to the extended Beckton Sewage Treatment Works. The Beckton Sewage Treatment Works was upgraded in 2013, with over 5km of Weholite high density polyethylene (PE-HD) pipe being supplied in different sizes ranging from 400mm to 3,000mm. The idea was to install the pipe for all of the associated chamber fabrications of this extensive, inter-process pipework project.
Uponor Project Services which, together with the licensee Asset International Limited, used its design expertise in land and marine applications to re-engineer the project. This involved the creation of a landmark design – the largest plastic outfall ever installed in the UK and one of the largest in the world in terms of diameter.
Uponor was able to bring deep expertise and enormous versatility to this ambitious project, which included 880m of 3,000mm diameter Weholite pipes laid as a twin culvert, alongside twelve large-scale Weholite modular PE-HD boxes. The project also involved the provision of installation, supervision and site services, and health and safety management.
The pipe-laying process consisted of a land section comprising 105m of twin culvert laid at 10m depths, in order to break through the tidal protection wall that prevents the Thames from flooding Europe’s largest treatment works at Beckton. A giant 7m x 11m x 5m Weholite modular box was used to house a 3,000mm spool section in order to complete the installation.
The operation to install the remaining 335 metres of twin culvert section in the River Thames was carried out by marine contractor CMP, alongside the Asset and Uponor PS partnership. This ambitious marine project was further complicated by the fact that the pipes had to be submerged under an existing jetty structure and sections of the project were often isolated by the tide (which rises and falls by up to 7 metres in the Thames), with no access by land.Once the pipe strings were ready, they were towed individually upriver by tugboat and submerged. Specialist divers were used to bolt the innovatively designed quick-connect flanges joining each pipe string.
Additionally, steel sheet piling of over 11,000m2 was installed to allow the riverbed to be dredged so that the pipes could be laid free of obstruction. Over 28,000m3 of riverbed materials were dredged, with much of the dredged material being reused to backfill theMVB
Uponor Infra Project Services
Linköpingin uusi infratunneli on 2,2 km pitkä ja halkaisijaltaan 2 200 mm. Tunnelissa kulkevat vesi-, jätevesi-, kaukolämpö- ja kaukokylmäputket, samoin esimerkiksi sähkö- ja datakaapelit.