This JV project required the design and construction of an extension to the largest onshore wind farm in Europe. Sisk in 50% JV partnership fulfilled the role of Principal contractor for the client and scope included design and construction of the following; 10km of excavated track and 34km of floating roads over deep peat, 68 turbine bases in peat depths of 3.3m, extraction/processing of one million m3 of rock from borrow pits and on site concrete batching of up to 45,000m3.

The access roads were completed in low-strength peat layers to 6m depth and turbine foundations required excavation up to 8.5m depth of peat with on-site water treatment using silt traps, lagoons and rock filtration systems.

The project ground conditions were challenging with the presence of peat layers exhibiting low-strength characteristics. This necessitated foundation excavation to depths of 6m of peat and the construction of floating roads over peat using Brash Matt and Geotextile.

The civil construction programme was completed on schedule in various weather conditions from the deep freeze of 2010, to the heavy Scottish rainfalls, in an environment of deep peat with depths of 6m recorded onsite with the construction team achieving the completion of 1.5 million man-hours on site without a lost time incident.