Following the sinking of a large trawler off the Canary Islands, Fugro was asked to provide deepwater subsea inspection and intervention services to Otech Marine Services AS. Innovative engineering solutions were required to access the vessel, plug the leaks and prevent leaking fuel oil from threatening the marine environment.
When a large trawler, laden with fuel, caught fire and sank to a depth of approximately 2,700 metres, Fugro was asked to provide emergency intervention to avoid leaking fuel oil threatening the local marine environment.
We began by quickly mobilising the ROV support vessel Grampian Surveyor. Its deepwater FCV 3000 ROV was used to locate and inspect the sunken trawler, so that we were fully aware of its status. Our inspection revealed that the fire and subsequent impact with the seabed had damaged the vessel's hull, and fuel was leaking from a number of places.
The damage sustained by the trawler demanded a range of engineering solutions, but before they could be deployed, we needed to know more about the vessel and establish how best to access the leak points.
Fugro engineers quickly produced 3D computer models of the trawler based on ship drawings and on-site measurements taken from a visit to a sister vessel of the sunken ship. This ensured we could engineer fit-for-purpose solutions and conduct simulation exercises using Fugro’s proprietary DeepWorks™ software. DeepWorks simulations enabled us to verify the operability of the engineered solutions and methods of accessing the leak sites.
The information we gleaned was used to draw up comprehensive work packs and procedures for use on Fugro's vessels, ensuring safe and efficient intervention.
We mobilised engineering personnel to liaise closely with local contractors and authorities. Bespoke engineering solutions were developed by our in-house subsea engineering team in Aberdeen and mobilised to the site within a matter of weeks.
A range of ROV-deployed tools, including cutters, wire rope, chains and handrails, were used to remove debris and cut away sections of the trawler's structure and bulwarks. This cutting and clearance operation, started by Grampian Surveyor, was later conducted from the ROV support vessel Fugro Saltire, which has two permanently mobilised FCV 3000 ROVs. They were used to carry out further intervention and plugging operations.
As the project progressed, Fugro was able to react to the changing conditions and dynamics of the wreck, producing bespoke solutions ranging from cofferdams of different sizes to a variety of mechanical plugs and innovative chemical sealants.
This challenging project demonstrated that, with its experienced in-house project personnel and access to a wide range of assets - including vessels, ROVs, survey and inspection equipment and specialist engineering services - Fugro is well-equipped to respond to deepwater emergency interventions.