BAM Ritchies

Case Study: Dunmaglass Wind Farm Ground Investigation

Client: Dunmaglass Estate

Designer: RES Ltd

Location: Dunmaglass, Scotland

Date: 2011

In April 2011, BAM Ritchies was appointed to undertake a site investigation south west of Inverness for a new wind farm of 33 turbines including access tracks with a contract value of approximately £250,000.

The fieldwork consisted of:

  • 44 boreholes by rotary drilling employing a Robit continuous casing drilling system
  • 93 trial pits using a wide tracked 14 tonne excavator
  • 161 Dynamic Probes
  • 342 Peat Probes.

BAM Ritchies used low ground pressure plant including two Morookas and three Hagglund BV206 all-terrain vehicles to negotiate the very soft moorland peat ground conditions.

The site access was very difficult and travelling from the base compound to the top of the hill took 30 minutes in 4x4 vehicles. In places the narrow access road was etched into the side of a cliff-face. The highest point of the site was 750m above sea level and the weather conditions were extreme – the team worked in a snow storm at the beginning of June! In addition, care was taken not to disturb protected species of birds, including Red Grouse and Golden Plovers, which were nesting in the area.

The site was challenging but the experience gained on previous wind farm contracts ensured that the work was completed satisfactorily and to stringent time constraints.