Cork Harbour Horizontal Directional Drilling
Project Location:
Cork Harbour, Ireland
Client Name:
Ervia / Irish Water
Project Description:
OCU was contracted to design and install twin 1,025 metre lengths of 500mm Diameter SDR-9 PE100 Foul Main under Cork Harbour using Horizontal Directional Drilling (HDD). A discharge chamber was constructed on the west shore, with tie-in works to connect to the existing network. Under a local road closure, the pipe was moved 1.5 kilometres from the fabrication area to the drill exit using 144 rollers, 3 cradles, 4 excavator clamps, and a 50-tonne hydraulic pusher.
Key Stats:
• 114 meters of 16-inch surface casing
• 400 tonne Mega Rig mobilised
5 Months
Duration
Challenge
• Cork Lower Harbour is designated as a Special Area of Conservation, a Special Protection Area, and a Natural Heritage Area
• To comply with the Urban Wastewater Treatment Directive, Irish Water and Cork County Council transferred 20,000 wheelie waste bins daily to a new treatment facility to prevent raw sewage discharging into Cork Harbour
Solution
• Redesign the bore path, adjust the reception shaft, and alter the pipeline fabrication to minimise risk
• Ecological and archaeological surveys, infrastructure inspections, riverbed dive survey, and noise and vibration assessments were conducted
• Boreholes were drilled at entry and exit to assess contamination risks, and a water supply bore was established for the HDD operation
• A bridge was built over the Glen Burn at the exit for access
Outcome
• The project exceeded 80,000 manhours with no reportable accidents or incidents
• OCU hit every KPI during these works and exceeded 98% on the client’s monthly audits
• Longest horizontal directional drills in Ireland and completed in a continuous effort of over 24 hours
• Our teams successfully pulled a pipe over 1.3 kilometres under the estuary
• Close liaison with the full project team and the local community to guarantee safety
