Canadian-Dutch partnership orders subsea rock installation vessels

CSL OWL Subsea Rock Installation, a newly formed partnership between Canadian shipping company the CSL Group (CSL) and Netherlands-based Offshore Wind Logistics (OWL), has placed orders for two subsea rock installation vessels tailored for the offshore renewable energy sector.

Each vessel will have a cargo capacity of 17,500 tonnes and will be equipped with a DP2 system. They will be able to operate on MGO and/or methanol and to deliver efficient 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, with the option of handling rocks weighing up to 450 kg. A specialised pipe with active motion compensation will ensure precise placement at water depths between 30 and 100 metres.

The vessels will also be fitted with transport belts designed to handle rocks weighing up to 1,500 kg and a side chute available for larger armour gradings. Excavators can be used to handle larger armour rock.

The vessels are scheduled for delivery between August and November 2026.