ENVIRONMENTAL CHALLENGES
The project was undertaken within a designated environmentally sensitive area, requiring strict adherence to environmental management procedures.
Stockton mitigated risk around the use of drilling fluids in close proximity to the River Corrib through:
• A specially formulated bentonite drilling fluid system
• Strict environmental controls and monitoring
• Full compliance with the construction environmental management plan
The proximity to Menlo Castle and the National University of Ireland Galway also required a carefully controlled drill profile to ensure no structural impact
DETAILED DESIGN AND DELIVERY
Stockton developed a detailed drill design to safely navigate beneath both the river and nearby heritage structures.
The bore profile was engineered as a continuous curve, starting at 13 degrees and following a 400m radius to maintain safe clearance from Menlo Castle.
Following pilot drilling, the bore was progressively reamed to 28” diameter to accommodate the pipeline installation.
HDPE pipe strings, pre-welded into 420m lengths, were tested and fitted with a custom-designed pulling head incorporating a water-filled buoyancy system to reduce installation forces.
A 500mm pullback reamer assembly was then connected, and the pipe bundle was successfully installed in a single continuous operation from exit to entry point.
Despite the technical complexity, environmental sensitivity, and proximity to critical structures, the works were completed safely and without impact to the surrounding area.
The successful completion of the River Corrib HDD crossing highlights Stockton Group’s ability to deliver complex trenchless installations in environmentally constrained and technically demanding environments.
