CSL OWL Subsea Rock Installation (CSL OWL SRI), a joint venture between The CSL Group and Offshore Wind Logistics (OWL), has placed an order for two subsea rock installation vessels to support offshore wind projects.
The DP2 vessels, with a cargo capacity of 17,500 metric tonnes, will be powered by marine gas oil (MGO) and/or methanol. Designed for flexibility, the vessels will feature a Tremie Pipe with active motion compensation, ensuring precise rock placement at depths between 30 and 100 meters.
The vessels can install rock material up to 450 kg, with transport belts handling rocks as heavy as 1,500 kg. A side chute will accommodate larger armour gradings.
CSL OWL SRI aims to support the offshore renewable sector’s growth by reducing the levelized cost of energy (LCOE) and minimizing emissions. The first vessel is expected to be delivered in August 2026, with the second to follow in November 2026.