Carradale to Crossaig Replacement Power Line
Argyll and Bute, Scotland SSE Card Geotechnics Limited AMEC MultiTrack™ 1000 & SX GRID™ 3030 65,000m2
As part of a scheme to provide a more secure power supply network on Scotland’s Kintyre Peninsula, and also to provide a power network capable of taking advantage of the regions renewable energy potential, a new 132kV overhead power line was required between Carradale substation and a new substation at Crossaig.
Due to the remoteness of the site, around 18km of access roads were required to enable access for the plant and machinery required to construct the 50 new pylons that would carry the new 14.4km power line. The access roads needed to be built in an ecologically sensitive environment across very challenging ground conditions. On completion of the project the roads would then need removal to return the area to its former state.
Wrekin discussed the requirements of the access roads with AMEC considering factors such as the ground conditions, the grading of the available stone and the fact that the access roads were only required for the project duration of approximately 2 years. Following this it was decided to install Wrekin MultiTrack™ 1000 geotextile and Wrekin SX Grid™ 3030 overlaid with compacted available stone. Additionally AMEC chose to use the system for their site compound.
Ordinarily Wrekin E’Grid™ 3030 would have been used to stabilise the ground and provide the necessary reinforcement. However, in this instance as the access roads were only temporary, the superior 100+ year design life of the E’Grid™ was not required and Wrekin SX Grid™ was perfectly adequate.
Wrekin SX Grid™ is a ‘punched and drawn’ polypropylene biaxial grid that has been specifically developed to provide engineers with a cost effective solution to their reinforced soil requirements where the superior optimised performance and associated longevity provided by E’Grid™ is not required.
By having a detailed understanding of the scheme requirements, Wrekin were able to offer technical support to deliver a cost effective and appropriately value engineered solution to the project.