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Case Study:    
Fishlake Siphon, Grill & Penstock, Romsey, Hampshire
Client:   Client Environment Agency (Richard Rowland – Romsey Office)
Cost:   £123k
Duration:   8 weeks (August/September 2010)
project Overview

The works included the provision of a sheet pile cofferdam to enable partial demolition of existing headwall structure and trash screen, excavation of the river bed and underlying peat strata, subsequent construction of new reinforced concrete structures, including a new headwall and capping beams, trash screens, penstock and extended culvert. The works were required to: (1) improve the trash screen operation and upgrade the structure to conform with current Environment Agency standards; and (2) reduce the risk of failure of the structure which would cause an uncontrolled release of water from the perched stream/canal which runs above it

All plant and machinery (apart from 40t All Terrain Crane) was sourced from our own extensive fleet which includes excavators (3-30t), tipper trucks (7.5-28t), dumpers, pumps, compressors and associated small tools, all based at our local commercial depots and at our Head Office on the Isle of Wight. All works were carried out by our full time local work force based on the Isle of Wight.

  • Original structure showing trash screen and headwall/wing walls with early signs of failure
  • Shuttering and support for reinforced concrete headwall with new 1.0m diameter culvert
  • New reinforced concrete base to river channel constructed within sheet piled cofferdam
  • Site access track for plant (inc. 40t All-Terrain Crane) protected by temporary timber matting



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