Ultrabeam Hydrographic teamed up with Unmanned Survey Solutions (USS) to conduct a pair of subsea gas pipeline inspection surveys in Northern Ireland.
Both companies are based in the UK and offer unmanned platforms as an alternative to traditional manned survey vessels.
The contract was awarded by Mutual Energy, which wanted experience on how unmanned autonomous platforms can increase the knowledge of their pipelines while reducing risk and overall cost.
"Mutual Energy contracted with Ultrabeam Hydrographic in August 2020 to perform inspection surveys of our Larne and Belfast lough crossing pipelines, key components of Northern Ireland’s natural gas transmission network," said Shane Rafferty, Group Engineer, Mutual Energy. "In a first for Mutual, an Unmanned Survey Vessel (USV), the “USS Accession”, provided by Ultrabeam’s project partners Unmanned Survey Solutions, was to be deployed. The project planning phase moved swiftly and seamlessly such that execution of the works commenced only a matter of a few weeks later, and was performed as programmed despite some inclement weather and sea states. We were pleased to see early data capture and quality provide assurance of equal standards to previous surveys, such that the assets could be returned a clean bill of health."
The challenges faced by these route surveys were solved by using an Accession Class USV built by USS. This 3.5m USV was fitted out with an R2SONIC 2024 high resolution multi-beam sonar, SBG Ekinox Navsight Inertial Navigation System and sound velocity sensors from Valeport.
The data was acquired in QINSy which was also used as the autopilot for the autonomous line running.
Two pipeline surveys were conducted along the Larne and Belfast Loughs using the Accession 350 USV. The weather was marginal, no incidents occurred and the project was completed on time and to budget. The joint venture between Ultrabeam and USS proved that autonomous surveys of inshore pipeline can be conducted safely and cost effectively compared to traditional manned solutions.