Rotech Subsea has completed export cable de-burial and re-burial work on the 480MW Saint-Nazaire offshore wind farm off France’s Guérande peninsula.
The Aberdeen-based contractor provided non-contact controlled flow excavation services.
Rotech Subsea mobilised for the job in the second quarter of this year deploying its next generation RS2 controlled flow excavator.
The project comprised de-burying cables C1 and C2 situated at two metres below MSBL, with the cables re-buried to the same depth following jointing operations by the client.
The subsea spread of equipment was deployed via crane to operate in water depths of between eight and 30 metres LAT, experiencing soil conditions including dense sands with a hard layer present at two metres, the company said.
Rotech said the RS2 operated “extremely effectively” de-burying the cable to client spec with one pass at progress rates of between two to three metres/minute.
Burial depth was achieved in one pass at a rate of one to two metres/min with the client requesting a second flushing pass as a contingency, it added.
Rotech Subsea Director of Subsea Stephen Cochrane said: “It was a privilege to have been selected to work with this leading submarine cable player on this scope of work and to deliver an extremely successful project.
“The performance capabilities of our RS2 meant the project was completed exceptionally efficiently, leading to a saving on total project costs.
“With the client delighted with the RS2’s exceptional performance, Rotech Subsea looks forward to future collaborations.
“With another successful high profile contract completed on time and on budget Rotech Subsea’s CFE suite of tools is firmly established as the method of choice for cable trenching in Europe and beyond.
“The enhanced capabilities of our suspended jet trencher RS tools mean they can provide deeper and narrower trenches than ever before, with trenching speeds more than double that of competing older mass flow excavation tools or other methods such as contact trenching systems and ploughs.”