Austin Cannons Grid & Primary Substation

CASE STUDY: Civil Asset Management

The fencing and security arrangements at Austin Cannons Grid and Primary at Kempston near Bedford were in urgent need of attention.

The site, which slopes from front to back, is situated between a river, its flood basin and a Primary School. This raised a number of technical problems, not least by the fact that the fencing system would need a substantial concrete ring beam/retaining wall for most of its length but it would also need to be constructed in marshland.

The cable depth information from Freedom proved to be very accurate and therefore invaluable in terms of the ring beam design.

Freedom created the original design in 2005, following a long and drawn out tender process the project was postponed for a period of time pending approval.

In February 2007, EDF Energy Networks gave the go ahead for the project and the Freedom team began the mobilisation process. The site was complicated due to the proximity of overhead lines and HV underground cables running across and in line with the intended route for the fencing. A substantial amount of tree and vegetation clearance work had to be carried out across the whole site prior to commencement.

When the site was clear of vegetation, Freedom were brought in to carry out a detailed site survey using ground radar equipment to determine the exact locations of the underground cable network and to assist in the risk assessment process which was needed in order to finalise the best fence line. The cable depth information from Freedom proved to be very accurate and therefore invaluable in terms of the ring beam design.

Work progressed for the next few weeks with the Freedom Civils team forming the concrete ring beam and creating a new access road and the Maintenance team erecting the new fence line.

The project was successfully completed and handed over to EDF Energy Networks at the end of May 2007.