Thames Water has chosen civil engineering contractor Barhale to bolster a 70-metre size of the two.6-metre diameter Thames Lee Tunnel underneath Primrose Hill the place it runs underneath the route of HS2.

The placement of the works will necessitate an unusually lengthy concrete pump – 800 metres horizontal plus the just about 50 metre depth of the Barrow Hill shaft at Primrose Hill – to the location of the works. Barhale has been working with concrete pump specialist Caumford to design a bespoke pumping answer.

The work will likely be carried out subsequent February.

The Thames Lee Tunnel (TLT) was constructed between 1955 and 1959 to hold water from the River Thames at Hampton Water Works to Lockwood Pumping Station on the Lee Valley Reservoir Chain. The 31 km tunnel, runs at a depth of 21 to 58 metrs and passes by way of 24 entry shafts of three.7 metres diameter. It was designed to switch 120 million gallons (550 megalitres) of water per day.

Shane Gorman, Barhale’s water director – southern area, highlighted the significance of the Thames Lee Tunnel as a part of London’s water infrastructure.

“The necessity for the TLT was recognized each to handle drought situations and to fulfill the necessities of latest housing and improvement in East London after the Second World Struggle,” he stated. “For greater than 60 years it has performed a vital position transporting water throughout the capital and these works are an vital measure to bolster a key a part of London’s water distribution community.

“The part we’re engaged on presents some further challenges: the precise web site of the relining is an unusually lengthy distance from an entry shaft and the degrees of service and utility congestion in Camden implies that we are able to’t sink boreholes. So designing a concrete-pumping answer that can work over greater than half a mile has been a key focus.

“We’ve got labored carefully with Thames Water on the design and scheduling of this undertaking. Such is the strategic significance of the Thames Lee Tunnel that outages can solely be scheduled for sure occasions of the yr and they’re contingent upon common storage ranges throughout the remainder of the community.

“We’ve got now recognized an acceptable window and stay up for profitable completion in February 2024.”

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