Rotterdam-based CSL OWL Subsea Rock Installation (CSL OWL SRI), a partnership between The CSL Group and Offshore Wind Logistics (OWL), has launched its first of two subsea rock installation (SRI) vessels.
The company announced in November 2024 that it had placed an order for the construction of two SRI vessels that will service the offshore wind sector and will be able to operate on marine gas oil (MGO) and methanol.
Construction of the first vessel, named Rock Star, started in September 2025 with the cutting of the first steel plate. The vessel is suitable for depths of up to 100 meters.
“The launch of the first of CSL OWL’s two new subsea rock installation vessels brings us one step closer to delivering a new level of capability to the offshore renewable energy sector,” CSL OWL SRI said on social media. “Purpose-built for precision and performance, the vessel combines dynamic positioning, precise rock placement and methanol capability to tackle demanding offshore projects.”
Rock Star hits the water
The DP2 vessels each have a cargo capacity of 17,500 metric tons and are 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 are designed to handle rocks weighing up to 1,500 kg, with a side chute available for larger armour gradings.
The second vessel is expected to be delivered in November 2026.