Corriegarth and Dunmaglass

The development of two new wind farms just south of the iconic Loch Ness presented the requirement for two new 132kV Trident wood pole lines. Requiring a compressed construction timescale spanning the winter months, NorPower was appointed Principal Contractor for the construction of both overhead lines.

The two lines, spanning over 20km in total, required erection of 238 H-pole structures, some of which are located at altitudes of 550 metres (1,700ft), supporting UPAS AAAC EHC conductor and an underslung ADSS fibre link.

Assessment of health and safety risks and environmental conditions and impacts identified the most practicable option was to have materials delivered by road transport to temporary lay down areas and flown ‘to peg’ by helicopter.

Ground conditions varied from very hard rock to soft peat at depths of 8 metres or more-and all soil types in between. This required the use of equipment from hydraulic rock breakers to a specialist shutter system which NorPower sourced, had developed and purchased in Australia.

Working in this type of environment presents challenges at any time of year and those challenges are multiplied during the Scottish winter. Forward planning and risk assessment saw the construction programme scheduling works to avoid site staff having to access the highest altitude sections in the depths of winter when the winter weather would be at its worst increasing safety risks and potentially stopping works.

Thanks to the hard work, skills and experience of all staff, the lines were completed in nine months- ahead of programme-and without injury or environmental incident.