Harlyn successfully delivered 12 km of inter-array subsea cable for an offshore wind development using its proven Roll-on/Roll-off (RoRo) transport system, ensuring full compliance and readiness for offshore installation.

The project involved cable lengths too short to justify traditional carousel-based transport, creating a logistical challenge that could have resulted in demurrage charges and port delays for high-value installation vessels. To avoid these commercial and operational risks, Harlyn applied its established RoRo-based solution, designed to minimize handling, optimize efficiency, and ensure transport safety.

Harlyn’s engineering team designed and oversaw the fabrication of customized cable baskets through Marine Repair BV in the Netherlands. Each basket was built to meet offshore transport specifications, focusing on spooling integrity, structural strength, and sea-fastening reliability. Once completed, the baskets were transported to Corinth, Greece, where Harlyn’s field team conducted controlled spooling and loading operations.

Using Self-Propelled Modular Transporters (SPMTs), the baskets were positioned precisely for cable winding. Harlyn’s BCE equipment — engineered to regulate cable tension and maintain consistent catenary geometry — ensured smooth and secure loading into each basket.

After completion, the fully loaded baskets were rolled directly onto the vessel via Harlyn’s RoRo operation, eliminating the need for crane lifts and reducing double handling. This approach significantly cut port turnaround time and effectively mitigated demurrage exposure.

For this operation, Harlyn chartered the Western Rock, a Hartman Seatrade vessel configured for flexible RoRo operations with ramp access and adaptable deck layouts. The Western Rock provided fast, predictable loading and discharge throughout the 96-day charter, supporting this and other Harlyn projects during its deployment.

The subsea cables were delivered safely from Greece to the United States, meeting all technical and offshore transport standards. The project confirmed the cost-effectiveness and reliability of Harlyn’s RoRo basket transport approach for short-length subsea cable movements — removing the need for onshore storage and minimizing handling risks.

“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.”