Work commenced on the project in February 2002 and was mechanically complete by November, despite inclement weather conditions during one of the wettest summers on record. In all, we delivered 350km of 750mm (30″), 85bar gas transmission pipeline, requiring 8,000 M 30″ OD gas pipeline, 22 crossings by trenchless means, 51 streams / rivers crossed by open cut methods and a 2km open-cut crossing of the Shannon Estuary at Foynes. Crossing techniques employed ranged from open cut to thrust and auger boring to directional drilling and mini-tunnelling. The trenchless crossing methods Included 1200mm OD pipe jacks, 1200 plus 1500mm OD tunnel boring machine, and two tidal rivers crossed using 1200mm OD TBM.
Use of automatic welding of gas pipelines was carried out for the first time in Ireland, as innovative techniques were required to negotiate difficult terrain including bog and rock, and to ensure minimal impact to environmentally sensitive habitat areas.
