Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Beleagured Glendoe hydro project needs 1.6km tunnel

Repairing Scotland’s £160M Glendoe hydro scheme will involve building 1.6km of drill and blast tunnel, it has emerged.

Owner Scottish and Southern Energy had earlier said that a single tunnel - thought to be around 200m long - would be needed to bypass a collapsed section of the headrace tunnel.

However, it has now admitted that this will be 900m long with an additional 700m long tunnel required for access to the damaged tunnel.

Bam Nuttall has been confirmed as the contractor carrying out the work - thought to be worth around £20M.

NCE understands that it will involve creating an appropriate entry point to the headrace tunnel and installation of a working platform within this tunnel to allow drill and blast plant to begin excavating the new bypass tunnel.

Cracks

A source close to the project told NCE it was also possible that sprayed concrete would be needed to patch up cracks within the headrace as well as grout infilling work to block off the section where the collapse occurred.

The collapse happened 2km from the top of the 6.2km long headrace tunnel that carries water from the reservoir in the Monadhliath Mountains to the power house near the southern tip of Loch Ness.

Estimates have put the volume of the blockage at around 20,000t, but the cause of the dramatic rockfall is not yet known.

SSE is now hoping that work will be complete in time for it to begin operating the station again in summer 2011.

The 100MW plant has remained shut since the collapse happened just a few weeks after it was officially opened by the Queen in June last year. However, the 2011 target is already a revised date from the original 2010 re-start it hoped for.

Readers' comments (2)

  • It will be interesting to see what is revealed when the drill and blast bye-pass tunnel encounters the same geological zone as the TBM presumably passed through with ease.

    Unsuitable or offensive? Report this comment

  • Why is the original contractor not repairing the tunnel collapse?

    Unsuitable or offensive? Report this comment

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.

Related Jobs