CSL OWL Subsea Rock Installation (CSL OWL SRI), a partnership between The CSL Group (CSL) and Offshore Wind Logistics (OWL), has announced the construction of two advanced subsea rock installation vessels tailored for the offshore renewable energy sector.
These purpose-built vessels are designed to support the offshore wind industry’s growing demand for efficient and sustainable solutions in subsea rock installation. The new vessels, each with a cargo capacity of 17,500 metric tonnes, will be equipped with state-of-the-art dynamic positioning (DP2) technology and dual-fuel capability, allowing them to operate on marine gas oil (MGO) and/or methanol. This innovation supports a pathway to zero-emission operations, aligning with the offshore sector’s sustainability goals.
Vessel Features and Capabilities
The vessels are engineered for optimal flexibility and performance in water depths up to 100 metres. Key highlights include:
- Rock Installation Capacity: Capable of installing rock material graded up to 60/300 kg, with options for handling rocks weighing up to 450 kg.
- Precise Placement: A Tremie Pipe with active motion compensation ensures accurate rock placement at depths between 30 and 100 metres.
- Enhanced Handling Systems: Transport belts designed for rocks weighing up to 1,500 kg, complemented by a side chute for larger armour gradings.
- Excavator Options: Equipment for handling larger armour rock when required.
Supporting Offshore Renewables
The vessels aim to deliver efficient and cost-effective solutions for bottom-fixed wind farms and their associated cables. By enhancing operational flexibility and reducing emissions, CSL OWL SRI seeks to contribute to the offshore renewable energy sector’s ambitions of increasing installed capacity, lowering the levelized cost of energy (LCOE), and achieving sustainable operations.
“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,” said Maarten van der Giessen, CEO of CSL OWL SRI. “We believe in making green energy affordable and are committed to doing our part by optimizing offshore renewable energy logistics.”
The first vessel is expected to be delivered in August 2026, with the second following in November 2026.
About CSL OWL SRI
CSL OWL SRI operates as an independent marine contractor specializing in subsea rock installation services. The Rotterdam-based company leverages OWL’s expertise in offshore marine construction and CSL’s leadership in marine solutions to deliver safe, sustainable, and cost-effective services.
About OWL
Offshore Wind Logistics (OWL) is a leading provider of logistics solutions for the offshore wind industry, focused on enhancing supply chain efficiency and financial performance. The company brings extensive experience and capabilities to support the sector’s evolving needs.
About The CSL Group
Montreal-based CSL Group Inc. is a world leader in marine dry bulk cargo handling and delivery services. Operating divisions such as Canada Steamship Lines, CSL Americas, CSL Australia, CSL Asia, CSL Europe, and CSL Transhipment manage a diverse fleet of self-unloading vessels, offshore transhippers, and Handysize bulk carriers. CSL delivers over 78 million tonnes of cargo annually to industrial clients worldwide and employs approximately 1,500 people. Founded in 1845, CSL has a rich history of innovation in marine solutions.
Source CSL OWL