Strabag UK has successfully finished a 1.2km exploratory tunnel for the Coire Glas pumped hydro storage.
- The tunnel construction was executed by over 100 specialists in a remote part of the Scottish Highlands.
- A rarely used drill and blast technique was employed to adapt to challenging geological conditions.
- The project aims to inform the design of a large-scale pumped hydroelectric storage scheme.
- Collaboration with environmental agencies ensured minimal impact during 24/7 operations.
Strabag UK has reached a significant milestone by completing a 1.2km exploratory tunnel for the ambitious Coire Glas pumped hydro storage scheme, located in the Scottish Highlands near Loch Lochy. This complex project involved more than 100 experts who have been working continuously since December 2022 at a site approximately 32km from Fort William.
The construction team, faced with varying geological conditions, applied the seldom-used drill and blast technique, which involves drilling holes into the rock, followed by controlled explosions. This method allowed for effective management of diverse rock types, facilitating the removal of fractured rock and the advancement of the tunnelling process.
As an integral part of the exploratory phase, the creation of the tunnel intended to provide crucial data about the geological environment of the proposed site. This information will guide the design for a planned large-scale hydroelectric project by SSE Renewables, with a potential capacity of up to 1,500MW, poised to significantly enhance the UK’s renewable energy storage capabilities.
The tunnelling operation cut a 4.5m wide passage towards the proposed underground powerhouse, following up with ground investigation to refine the subsequent design stages. During its construction, compliance with environmental standards was a priority. Collaboration with the Scottish Environment Protection Agency ensured that tunnel effluent and noise emissions were closely monitored to minimise their ecological footprint.
Notably, the demanding project required meticulous planning and execution, running constantly in shifts spread across 24 hours a day, seven days a week. The involvement of companies such as Stantec, as the overall reference designer, underscored the collaborative effort that brought together various stakeholders to realise this ambitious endeavour.
Reflecting on this achievement, Simon Wild, Strabag UK’s Managing Director, highlighted the success in establishing a fully operational site in a remote location, and praised the employment of the drill and blast technique as a demonstration of industry-leading expertise. SSE Renewables’ Mike Seaton acknowledged the completion of this phase as critical for de-risking future project developments.
The successful completion of the exploratory tunnel marks a vital step towards the realisation of Coire Glas’s hydroelectric ambitions.
