PROJECT ORWELL

Major Tunnelling Scheme Completed 6 months ahead of Schedule

March 2000 saw the completion of a major new sewer under the town of Ipswich in Suffolk and also marks the end of A F Howland Associates long association with the scheme.

The scheme for client Anglian Water, involved the construction within the primary Chalk aquifer of a 2.44m diameter segmentally lined tunnel up to 50m beneath the town, 12 access shafts up to 45m deep through overlying Tertiary deposits and an emergency overflow into the River Orwell Estuary.

A F Howland Associates were involved with the project approximately 2 years before the main contractor started on site. Initially completing a £1m Ground Investigation and then advising the project team on the geotechnical aspects of the design.

The investigations have lead to a significant increase in the knowledge of the deep geology of the area, an area, which until the present scheme was largely unknown due to a lack of surface exposures.

Client: Anglian Water

Scheme Cost: £30m