Quoich Landslip Temporary & Permanent Repair


Quoich Landslip Temporary & Permanent Repair

In November 2018 a landslide near Quoich Dam brought down a steel lattice tower on the Quoich to Broadford 132kV OH Transmission Line. NorPower Director, Neil Lamont supported by a team of our site staff worked with SSEN, the local council, geological advisors and designers to assess the damage and the site conditions to agree a suitable and safe solution for the repair of the line which is the main electricity supply to Skye and the Western Isles.

Our fleet of plant and equipment meant NorPower was able to mobilise quickly to site where our staff installed backstays on the steel towers immediately before and after the felled tower. With the site assessment indicating that there was a risk of further rock/landfall, it was agreed to install a temporary diversion using four Trident H-Poles- two at either side of the danger zone.

Following erection of the poles, wiring was undertaken at each side of the fall area and a helicopter was used to carry out the conductor stringing across the danger zone.

In addition to the 132kV repair works, NorPower assisted with repairs to the 33kV distribution line also damaged by the landslide.

In 2019, NorPower was contracted to undertake rerouting of the line, installing four Trident H-Poles and transferring conductors from the temporary emergency repair to the new line in order to clear a suitable route for a permanent replacement.

NorPower was appointed Principal Contractor for the permanent replacement of the OHL in 2021 using three New Suite of Transmission Structures (NeSTS) each comprising of 4 sections and crossarms supporting insulators with a nominal height of 34 metres. These three structures replace the temporary wood pole line and a further four steel lattice towers.

Our trusted sub-contractors undertook civil works to install accesses and crane platforms, piling and foundation installation.  NorPower site staff assembled the structure sections which were lifted into place by crane with NorPower staff tensioning the structures and installing ACDs.

New Araucaria 700mm2 conductors were strung along the route of the NeSTS poles and the old towers and wood poles were removed from site.

Previous use of this type of structure is minimal in the UK and, with the line running in close proximity to the public Kinloch Hourn road and in very challenging ground conditions, the project involved many challenges for which NorPower is known to be competent to overcome. The works were completed as required with no injury or environmental incidents.