Tunnel award seals Irish gas project Jun 2012
Peter Kenyon, TunnelTalk
- BAM Nuttall and sister BAM subsidiary Wayss & Freytag of Germany is awarded construction of the 4.9km onshore tunnel section that will complete the long-awaited offshore Corrib gas field project in northwest Ireland.
Sruwaddacon Bay in northwest Ireland
- The contract award is for a 3.5m i.d. TBM bored tunnel under the Sruwaddacon Bay estuary in Ireland's County Mayo. The tunnel will link the Bellanaboy inland gas refinery and the 80km section of undersea pipeline that will bring gas from offshore platforms in the Corrib field.
- A 4.24m diameter Herrenknecht slurry TBM, fitted with 21x14in cutter discs, will excavate the tunnel. The machine has already been completed at the German manufacturer's Schwanau factory and is expected to be shipped to Ireland later in the Summer.
- The project owner is a consortium led by Shell E&P Ireland (SEPIL), with Vermillion (Canada) and Statoil (Russia) as minority partners. Design consultant RPS completed the planning, engineering, environmental impact statement and the local stakeholder communications for the onshore element of the project, including two alignment redesigns (2009 and 2010) to enable the project to win planning approval last year (2011).
4.9km tunnel alignment under Sruwaddacon Bay
- Pre-construction works, including the launch pit, are already under way, with tunnelling expected to start at the end of this year for a completion in early 2014.
- Ground conditions are anticipated to be a mix of quaternary sands, gravels and gneiss. The tunnel will be lined with a 250mm thick steel fibre reinforced segmental lining. The scope of the contract also includes installation of a 50cm diameter carbon fibre pipeline that will be backfilled into the completed tunnel.
- Theo Cullinane, Chief Executive of BAM Contractors, said: "We are delighted to be working with Shell on the Corrib tunnel, which is one of the most significant energy infrastructure projects in Ireland's history. During the construction phase 100 full-time jobs will be created, including project management, engineering and tunnelling specialist roles." At its peak in 2013 the tunnelling work is expected to support up to 1,000 local jobs.
- The project has had a chequered history. Years of delays, environmental protests and legal challenges were only finally overcome once a tunnel for the on-land part of the alignment was incorporated into the project's overall design. Initially Shell had wanted to run the pipeline above ground.
4.24m Herrenknecht TBM is ready to ship
- The consortium of oil giants who are now involved in the ownership of the project had already invested heavily in developing the Corrib field and by 2009 a tunnel was being considered as a way of completing the final piece of the project puzzle. By the time gas starts to flow to the mainland it is estimated the project will have cost nearly €3.3 billion. In February this year (2012), Shell Ireland Managing Director Michael Crothers, announcing the injection of a further €800 million on top of the €2.4 billion already spent, said a "significant chunk" of this extra cash was to pay for the onshore tunnelling works.
- Once completed in 2015 the Corrib gas field has the potential to supply up to 60% of Ireland's gas needs at peak production.
Add your comment
- Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.