First breakthrough on Brighton sewer project

Boring for the new sewer tunnel between Ovingdean and Marine Drive in Brighton saw breakthrough after 119 days.

Work started in June by 4Delivery, a JV consisting of Costain, MWH and United Utilities. Excavation was carried out by a 62-t, 2.44m outer diameter TBM, named ‘Alice’ by local school children.

The bore was 1783m long through chalk, excavated at a rate of a metre every 10 minutes.

“A great cheer went up at the reception shaft when her teeth appeared through the concrete wall. It was truly a celebratory moment for the engineers, miners and the management team alike,” said Julian Smith, project manager for Southern Water.

The TBM will be returned to Ovingdean to begin another bore towards the under-construction Portobello Pumping Station in Telscombe to the east.

"This is a fantastic achievement by the team,” said 4Delivery Infrastructure project manager for the scheme, Craig Reade.

“The first tunnel breakthrough is a significant milestone in this complex project and I am pleased to share with our client the recognition of the site team's hard work and effort since the start of the project over a year ago."

Another TBM (‘Hollyblue’) is boring from the wastewater treatment works at Peacehaven to the pumping station at Portobello. This TBM will then also be returned to begin excavation of a tunnel between Peacehaven and Friars Bay.

Pipejacking will be used to lay remaining sewers.

Southern Water’s GBP 300M (USD 472.9M) ‘Cleaner Seas for Sussex’ project consists of approximately 11km of new sewers (9km by Alice and Hollyblue) as well as a new wastewater treatment works and a sludge-recycling centre (see feature coverage in T&TI September 2010 p23).