Rotech Subsea has completed the sandwave clearance and debris removal operations at an unnamed offshore wind farm in Taiwan.
The contract – for a long-term client in the region – saw Rotech mobilise its TRS2 controlled flow excavation (CFE) and RSBG (Boulder Grab) spreads of equipment from its base in Aberdeen specifically for this scope of work.
Operating in water depths of 12 metres to 40 metres, the TRS2 tool carried out sandwave clearance ops along multiple cable routes, progressing at 2 metres to 5 metres per minute.
Rotech’s RSBG grab tool removed and relocated debris identified along the route.
Working in loose sand conditions, the initial work scope saw the sandwaves pre-swept to client specifications within the trenching assets working limits.
Each trench was required to be between 12 metres to 15 metres wide with a maximum gradient of 15 degrees.
To achieve this, and keep an open trench, several passes were required with the TRS2 operated perpendicular to the cable route at varying heights of around 3 metres to 6 metres from MSBL to give a wide spread of flow, the company said.
Upon successful completion of the sandwave clearance and debris removal, extra cable burial trials using Rotech’s TRS1 LD jet trencher were requested by the client, with a future project phase in mind, it added.
Rotech subsea director of Subsea Stephen Cochrane said: “This was another extremely successful deployment in the region for our patented jet trenching systems and debris removal tools.
“Taiwan is a great success story for Rotech with our project teams and suite of tools having been near permanently deployed in the offshore sector since the successful delivery of our first project there in 2019.
“At time of writing we are engaged on a further three significant projects in the region for the same client with follow on scopes mooted for 2024.”
Rotech Subsea’s research, development and engineering team has created a suite of 18 sector-leading non-contact CFE, Suspended Jet & Hybrid Jet Trenching tools in-house at its Aberdeen headquarters.
With enhanced capabilities, Rotech Subsea’s CFE & Hybrid Jet Trenching suite of tools is firmly established as the method of choice for offshore wind farm cable trenching and excavation in Europe and beyond.