Sudbrooke, Chepstow UG & OHL

JSM as Principal Contractor undertook works for the installation of 2No 132kV single core cables.

The project involved the installation of a new 132kV cabled underground ducted system at Towers P62/P63 and P69/P69A which was constructed across agricultural land. The duct system was installed by open cut trench across the agricultural section and a HDD was required under a stream as requested by the environment agency. Once all the duct system was constructed the 132kV cable circuits were installed up to the SE temporary location with sufficient cable laid off to allow the SE to be lifted into its final location on the SEP.

Due to the existing piled foundations at each of the Towers, the SE Platforms required modifications resulting in the platform being raised by 750mm, subsequently reducing the electrical safety clearances.

The preferred option to complete the 12No ODSE terminations by the traditional method with cables installed and supported at the termination position was no longer possible. A temporary sealing end cradle supports/outrigger was attached and supported to the back of the cable ladder and the SE termination were prepared and terminated (complete with insulating compound) at this level as per the design. The cable and SE were then lifted into its final position onto the SEP under a controlled lift using cable turfers, lifting frame and specially designed supporting cradle. This methodology enable us to minimise the circuit outage period.

JSM’s principal responsibilities within the contract were:

  • Ensure compliance with all Health, Safety & environmental legislation and requirements
  • As CDM, ensuring compliance and the management of the supply chain and subcontractors utilised on the project
  • SSSI Management. A HDD was required to avoid a section of the scheme that was deemed SSSI. JSM successfully completed the directional drill whist meeting the relevant legislation
  • Negotiating and dealing with wayleave agreements and Environment Agency for all open cut and HDD works
  • Co-ordinate and deliver the project within the programme and budget
  • Produce and manage all Drawings and records.