Proven RoRo Transport Method Mitigates Port and Demurrage Risks Offshore Wind Project
Project info:
Cable Length
12km IAC
Location
Corinth
Project Type
Cable Spooling and Transportation
Charter
96 Days
Global Project Transportation
When our client required 12km of inter-array subsea cable for a developing offshore wind project, the challenge was clear — the cable length was too short to justify traditional large-scale carousel transport. This presented significant commercial risks: potential demurrage costs on expensive installation vessels and delays at the loading port, both of which could impact the offshore construction schedule and project economics.
To address these challenges, Harlyn implemented its tried and tested RoRo-based transport method, providing a safe, efficient solution that removed the need for double handling and minimised time alongside port infrastructure or high-cost vessels.
Complex Challenges Managed
The challenge:
Cable length was too short to justify traditional large-scale carousel transport.
Significant commercial risks, including potential demurrage costs on expensive installation vessels.
Risk of delays at the loading port, potentially impacting the offshore construction schedule and project economics.
Need to avoid double handling of cable to prevent damage and inefficiency.
Requirement to minimise time alongside port infrastructure or high-cost vessels.
Efficient and Quick Solutions
Because the cable length did not justify full-scale carousel transport, Harlyn used its established method involving custom-engineered cable baskets optimised for shorter-length subsea cable handling.
The baskets were designed by Harlyn’s engineering team and fabricated by Marine Repair BV in the Netherlands. Each basket was engineered for secure spooling, structural stability, and sea-fastening efficiency to ensure full compliance with offshore transport requirements.
Once fabricated, the baskets were transported to Corinth, Greece, where Harlyn’s field team managed the spooling and loading operations. Using Harlyn’s own Self-Propelled Modular Transporters (SPMTs), the baskets were rotated and aligned for accurate cable spooling. The operation utilised Harlyn’s BCE equipment — a precision handling unit designed to manage cable spooling tension and control winding cable catenary geometry — ensuring the cable was loaded evenly and securely within each basket.
The solution:
Applied Harlyn’s tried and tested RoRo-based transport method, removing the need for double handling and reducing port time.
Used custom-engineered cable baskets optimised for shorter-length subsea cable handling instead of full-scale carousel transport.
Baskets designed by Harlyn’s engineering team and fabricated by Marine Repair BV for structural stability, secure spooling, and sea-fastening efficiency.
Harlyn’s field team managed spooling and loading operations in Corinth, Greece.
Employed Harlyn’s BCE equipment to manage cable spooling tension and catenary geometry for secure loading.
Used Harlyn’s SPMTs to rotate and align baskets for accurate cable spooling.
Implemented RoRo loading and discharge to drive baskets directly on and off the vessel, eliminating cranes and double handling.
Chartered the Western Rock, whose ramp access and deck configuration enabled rapid loading, reduced interface risk, and ensured safe transfer from Greece to the U.S.
Outcome
Proven Method Delivered
Harlyn successfully delivered 12km of inter-array subsea cable on time and in full compliance by applying its proven RoRo basket transport method, which mitigated demurrage and port delay risks, eliminated double handling, reduced damage exposure, and provided a cost-effective alternative to carousel transport. The approach ensured safe, predictable operations from spooling through final delivery, while avoiding the need for additional onshore storage and maintaining full technical assurance throughout the 96-day international transport campaign.
This project demonstrated how applying a proven method can remove unnecessary risk and delay,” said Hamish Adamson, Managing Director of Harlyn. “Using our own SPMTs, BCE equipment, and RoRo process, we ensured the operation ran smoothly and safely, with complete control from start to finish.
Hamish Adamson, Harlyn Managing Director
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