CSL OWL Subsea Rock Installation (CSL OWL SRI), a newly formed partnership between Canadian-based The CSL Group (CSL) and the Dutch Offshore Wind Logistics (OWL), announced last month that it has ordered two subsea rock installation vessels tailored for the offshore wind sector.
The first subsea rock installation vessel is scheduled for delivery from the shipyard in August 2026, followed by the second vessel in November 2026.
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 metres. The vessels will be capable of installing rock material up to the 60/300 kg grading (heaviest rock weighing up to 450 kg). A Tremie Pipe with active motion compensation ensures precise placement at any water depth up to 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 be used to handle larger amour rock.
CSL OWL SRI is an independent marine contractor specializing in subsea rock installation services, dedicated to delivering safe, sustainable and cost-effective solutions for the installation and maintenance of subsea rock. 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.
OWL is renowned for its top-tier logistics solutions in the offshore wind sector, further enhanced by its industry-leading capabilities. The company was founded to enhance the efficiency of the offshore wind logistics supply chain, both operationally and financially.
The CSL Group is a world class provider of complex marine solutions and the largest owner and operator of self-unloading ships in the world. Headquartered in Montreal with operations throughout the Americas, Australia, Europe and Africa, CSL provides a broad range of shipping and handling services, and delivers millions of tonnes of cargo annually for customers in the construction, steel, energy and agri-food sectors. Source: CSL OWL SRI
