Gas Networks Ireland contracted Murphy to lay, test and commission a 41km gas pipeline from Craggs AGI near Foynes in Co. Limerick to Listowel town, Co. Kerry. The route followed the national primary route (N69) towards Foynes, diverged through the towns of Shanagolden, Ballyhahill and Moyvane, and then re-joined the N69 up to Listowel.
The works included installation of R465 type district regulators and all connections to the existing pipework. An SP4 pressure reduction skid (PRS) unit was fitted within the grounds of Kerry Ingredients in Listowel, along with associated pipework connections. Pipeline offtakes were also installed for new customers. To finish the works, 3km of the N69 was resurfaced with stone mastic asphalt (SMA).
Traffic management was a key challenge throughout the project, particularly on the N69 and the 38km of minor roads between Foynes and Listowel. This, and all necessary diversions, were managed successfully by our careful planning and early engagement with local authorities.
It was a challenge to manage the eight different subcontractors that were working concurrently at different locations along the route. However, this was successfully overcome by having regular work reviews and engaging proactively with the subcontractors.
Management and liaison was required during wayleave development and also with respect to stakeholders in Listowel, ensuring minimum disruption during works. A tight programme was adopted to allow gas to be delivered to the food group, Kerry Ingredients, in time for their change over to natural gas.
The 41km gas pipeline ran from the tie-in position at Craggs AGI to Listowel. Laying, testing and commissioning the 400mm diameter four bar polyethylene (PE) 100 gas feeder main was carried out between July 2017 and August 2018. This included 11km of medium and low pressure PE pipelines in Listowel town, Moyvane and Ballyhahill, some of which were laid within the same trenches as the 400mm PE main.
The works needed thirty directional drill crossings at culverts, road junctions, roundabouts and rivers. Specialist horizontal directional drilling (HDD) contractors, GMAC Utilities and Mc Cormack Drilling, were contracted at an early stage to undertake this work. One of the crossings went under the River Feale in Listowel town at a depth of 10m and cut through the rock beneath the river bed for a distance of 200m.
Two river crossings were undertaken by an open-cut method and these required electrofishing prior to the excavation works. Electrofishing is a survey method used to sample fish populations, determining abundance, density and species composition. When performed correctly, it results in no permanent harm to the fish, which return to their natural state in as little as two minutes after being caught.
Two R465 type district regulator installations (DRIs) were fitted in Listowel and additional ones at Moyvane and Ballyhahill. An SP4 PRS unit was installed on the grounds of Kerry Ingredients. All of these required connections to new and existing pipework.
Pipeline offtakes for new customers were installed during the course of the project and to finish, 3km of the N69 was resurfaced with SMA.