Photo credit: CSL Group Inc. (CSL)
Rotterdam-based CSL OWL Subsea Rock Installation (CSL OWL SRI), a newly formed partnership between The CSL Group (CSL) and Offshore Wind Logistics (OWL), has placed an order for the construction of two subsea rock installation vessels that will service the offshore wind sector.
The vessels will each have a cargo capacity of 17,500 metric tonnes and will be able to operate on marine gas oil (MGO) and/or methanol.
According to CSL, they are purpose-built for optimal flexibility and each vessel will be equipped with dynamic positioning (DP2).
The vessels will be capable of installing rock material up to the 60/300 kg grading, with the option of handling rocks weighing up to 450 kg.
They will feature a Tremie Pipe with active motion compensation that ensures precise placement at water depths between 30 and 100 metres.
The transport belts are designed to handle rocks weighing up to 1,500 kg, with a side chute available for larger armour gradings. Excavators can also be used to handle larger amour rock.
The first subsea rock installation vessel is scheduled for delivery from the shipyard in August 2026, followed by the second vessel in November 2026.
To remind, CSL OWL SRI is an independent marine contractor specializing in subsea rock installation services.
“We are committed to providing tailormade capacity to the fast-growing offshore renewable sector. This will support the sectors’ ambitions of ramping up installed capacity, reducing the levelized cost of energy (LCOE) and minimizing emissions,” said Maarten van der Giessen, CEO of CSL OWL SRI.
