BAM Civil Ltd and Wayss & Freytag Ingenieurbau AG have been awarded the contract by Shell E&P Ireland Ltd for the construction of a 4.9km tunnel as part of the Corrib gas project, one of the largest energy infrastructure developments in Ireland in 2012.
The tunnel, which will be constructed beneath an estuary on the north-west coast of Ireland, is a key element of the onshore pipeline works, which is the final phase of the Corrib project that remains to be completed.
Work on the contract has already commenced, with preparations for the installation of the tunnel starting shaft currently under way. A TBM with an internal diameter of 3.5m will be used for the work and this is expected to arrive on site during the summer. Tunnelling is planned to start towards the end of the year and is expected to take around 15 months to complete.
As soon as the tunnel has been constructed and the TBM removed, the 20-inch gas pipeline will be installed in the tunnel. Once the pipeline and services have been successfully installed and tested, the remaining tunnel void will be backfilled with grout. The project is expected to be completed in late 2014.
The Corrib gas field lies about 80km off the north-west coast of Ireland and is strategically important from an energy security perspective as it has the potential to supply up to 60% of Ireland’s gas needs at peak production.