The requirement was the replacement of the Little Barford 132kV Air Insulated Switchgear (AIS) with new Gas Insulated Switchgear (GIS) at Little Barford and to establish 3rd Super Grid Transformer (SGT) connection with a single 132kV cable route between Little Barford and Eaton Socon with the objectives of...
- Security of supply at Eaton Socon, Burwell and Sundon GSPs and major settlements including the City of Cambridge, Bedford and St Neots.
- Reinforce the networks capacity.
The project involved a new cable route from Little Barford Grid to Eaton Socon Grid with a spare set of ducts in a separate parallel circuit for future usage. This required two HDD’s at each to location to install seven 180mm SDR11 electric cable ducts in each.
A series of long and complex drills
As complex goes, the Little Barford to Eaton Socon project had it all; an important river, a golf course, flood plains, two national trunk roads, and a large industrial estate to cross in addition to pipe string out restrictions. It was even once labelled as a project that ‘could not be built’.
McCormack Drilling undertook the design of the HDD’s which included extensive surveys, calculations, extra ground investigation to complement the existing information through to obtaining approvals from Highways England to cross under the A1 and A428 roads.
- Utility: Electricity
- Length: 850m x 2 shots, 230m x 2 shots, 750m x 2 shots, 220m x 2 shots
- Depth: 13 - 25 metres
- Pipe: 7 x 180mm SDR11 PE100 ECD pipes in 2 circuits
- Geology: Oxford Clay Formation