Thornhill Gas Pipeline, Lough Foyle Shallow Marine Geotechnical & Geophysical Investigations

A combined marine geotechnical and geophysical investigation was carried out along the route of a proposed new gas main, crossing the River Foyle close to Lisahally Port.

The site Investigation comprised the following elements:

• Undertaking a bathymetric survey along the route of a new proposed submarine pipeline
• Sub Bottom profiling of river bed sediments using both Geoaccoustics CHIRP sub-bottom profiling system.
• Side scan sonar survey using a Klein 3000 “tow fish”
• Magnetic gradiometry survey to locate and identify buried metallic debris
• 6nr marine cable percussion with rotary core follow on to depths of up to 25m below river bed, undertaken from a jack up barge.
• 3nr land cable percussion and rotary boreholes at landfalls on the north and south river banks
• Laboratory testing
• Factual and interpretative reporting