A new interconnector substation is rapidly taking shape on the banks of the River Severn at Port Ham, Gloucester. The £12 million substation replacement project is being undertaken by an ABB and Balfour Beatty consortium on behalf of Central Networks (the new name for Midlands Electricity and East Midlands Electricity).
The steel superstructure for the new indoor substation building raised on stilts has been completed and the exterior cladding is now being fixed in place ready for the delivery of ABB’s state of the art compact ELK- 04 GIS (gas insulated switchgear).
Because the new indoor substation building is in the river flood plain significant foundation works were required. Each steel column in the building is supported by three cast concrete piles driven down 15m to the bedrock.
The consortium is providing a complete design, construction and installation service for the new substation which is expected to become operational towards the end of 2006. It features 20 bays of switchgear and provides a 132kV interconnection for four incoming and twelve outgoing circuits. The Port Ham interconnector substation is a grid supply point, which feeds electricity from the National Grid substation at Walham into Central Networks’ distribution network. This network feeds most of Gloucestershire and Herefordshire and parts of south and east Worcestershire – the equivalent of over one million homes. The existing AIS (air insulated switchgear) substation, built in the early 1950s, has been subject to above average load growth and its reliability has deteriorated. It is now reaching the end of its useful life and is being replaced to ensure continued reliability of supply.