RamWall – Crossaig Ravine 1 and Ravine 2 access

Project: Crossaig Ravine 1 and Ravine 2 access

Owner: Scottish & Southern Energy

Designer: Tony Gee & Partners LLP / OTB Engineering Ltd

Contractor: Amec Foster Wheeler Group Ltd, Power & Process Europe

Purpose: Retained embankments with culverts across steep ravines to support
heavy trafficking access to a transformer substation.

RamWall type: 8m diameter 200mm x 200mm galvanised RAMWALL mesh plus 5mm
diameter, 50mm x 50mm galvanised facing mesh, 25mm rebar spikes

RamWall Fill: Graded granular fill

Date: January to April 2015

The Carradale to Crossaig electricity supply project involves the installation of a 13 kilometre long transmission link located on the remote Kintyre Peninsula in Western Scotland from Carradale to the south heading north to Crossaig. Due to the remote location the working area had to be accessed via a forestry track that cut across the high ground across the peninsula. This route required major upgrading in order to carry several heavy transformer units to the substation located at the extreme end of the peninsula. This required the construction of two culverted embankments crossing steep ravines and carrying fast flowing streams. Further environmental and topographical constraints were imposed to limit the width of the embankments requiring them to be retained on either side by vertical walls. 1 metre wide RAMWALLS up to 7 metres in height were designed to be tied by horizontal steel bars across the width of the structure which was filled using locally sourced granular fill, which was placed and compacted in layers as the RAMWALLS were constructed. In order to meet the very tight deadline for the movement of the first 80 tonne transformer the structures were completed in just 10 weeks from the commencement of design.