Scurf Dyke

Freedom was contracted to install a 132kV POC-MAST™ tee-off connection on the Northern Powergrid's 132kV OHL network. The POC-MAST™ connected a 49.9MW solar PV farm near Driffield in the East Riding area of Yorkshire. Originally, a traditional solution involving a replacement 132kV tower was planned as the Point of Connection (POC). This approach would have required a temporary diversion of the Overhead Line (OHL) to facilitate the new tower being built – a time-consuming and costly process.

Using POC-MAST™ meant that a replacement tower was not required, as it connects directly to the existing OHL tower. The installation works, including the screw-anchor foundations and mast assembly, were mostly completed before the outage because the POC-MAST™ was installed offline in a shorter window. A brief outage was taken on the connecting circuit only to facilitate the installation of the POC-MAST™ cross-leads to the tower. The reduced outage requirements provided the client and the distribution network operator (DNO) with greater program flexibility.

The site presented challenges, including an Internal Drainage Board drain running perpendicular to the existing OHL, which required a 9m clearance buffer for maintenance. This constraint was overcome by lifting the POC-MAST™ into place using a base hinge and hydraulic cylinder, which can be rotated to lay it down in any direction to avoid obstacles. Additionally, the POC-MAST™ did not require space for a crane and associated working platform, unlike the traditional solution.

The POC-MAST™ is particularly useful for sites with limited space since it minimises the footprint, allowing clients to optimise the use of their site. Furthermore, the jumpers to the cable sealing ends were installed at 90° to the mast, further minimising the compound size by having the plant parallel to the OHL.

The complete POC-MAST™ installation took just 10 working days, whereas a new tower and associated diversion would have taken considerably longer – many months - and required multiple outages on both circuits, along with significantly higher costs. This is the first time POC-MAST™ has been utilised on the Northern Powergrid network.

“Thank you to the Freedom team, it’s been a pleasure working with yourselves. You have a well-designed product and a good team delivering a quality project. Ged Hammel (Senior Policy & Standard Engineer) and I, have expressed our satisfaction with your product and installation within the Northern Powergrid team and I’m sure that more will be used on future Northern Powergrid projects”. 

Phil Dickson, Project Manager / Major Projects