CSL OWL Subsea Rock Installation, a newly formed partnership between the CSL Group and Offshore Wind Logistics (OWL), has ordered two newbuild subsea rock installation vessels tailored for the offshore wind sector.
Each vessel will have a cargo capacity of 17,500 metric tonnes and will be equipped with dynamic positioning (DP2).
They will be able to operate on marine gas oil (MGO) and/or methanol, providing a pathway to zero emission operations.
Purpose-built for optimal flexibility, these vessels will deliver efficient and cost-effective subsea rock installation services in water depths up to 100 meters.
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.
The transport belts for the vessels are designed to handle rocks weighing up to 1,500 kg, with a side chute available for larger armour gradings.
The first subsea rock installation vessel is scheduled for delivery from the shipyard in August 2026, followed by the second vessel in November 2026.
CSL OWL SRI is an independent marine contractor specializing in subsea rock installation services. Based in Rotterdam, the company combines OWL’s extensive experience in the offshore marine construction sector with CSL’s expertise as a leading provider of complex marine solutions.
“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.
“Our subsea rock installation solutions are specifically designed to enhance flexibility and cost efficiency for operations in and around bottom-fixed wind farms and associated cables. We believe in making green energy affordable and are committed to doing our part by optimizing offshore renewable energy logistics,” said Maarten van der Giessen, CEO of CSL OWL SRI.