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

Tunnelling breakthrough for Olympic power lines

The breakthrough of two of the four tunnel boring machines (TBM) currently driving tunnels for the undergrounding of power lines over London's Olympic Park was confirmed by 2012 bosses yesterday.
Two 4.15m diameter TBMs moving in opposite direction underneath Stratford, east London have been boring the tunnels to divert National Grid powerlines, while two 2.82m diameter TBMs have been doing the same for EDF Energy power lines.One of each has now broken through, with the third and final TBM breakthoughs expected after Easter.Contractor on the £80M project is Murphy, with Faber Maunsell as consulting engineer and Arup the Olympic Delivery Authority's (ODA) checking engineer.ODA chief executive David Higgins praised the project's 'tremendous' health and safety record, which has now passed 1M man hours without incident.Murphy managing director James O'Callaghan also praised the record given the challenging nature of London's geology.'The geology has been extremely variable,' said O'Callaghan.'It quickly moves from hard clays to very very soft silts and muds, and we have been working under three bar pressure for most of the drive.'This variability forced the contractor to constantly change the additives it used to condition and stabilise the ground.Currently 52 pylons dominate the landscape in the area making any development difficult. The tunnels will enable the power needed for the Games and the community post-2012 to be carried underground and allow construction work to start next Summer. All tunnelling work is on track to be completed this Summer. Cables and ventilation will then be installed allowing for switchover in Summer 2008.

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.