Harlyn Mobilises JD Assister and T3200 Trencher for Major U.S. Offshore Wind Project

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In August 2024, UK-based engineering firm Harlyn Solutions completed the mobilisation of the JD Assister for Enshore Subsea, transporting the 170-tonne T3200 trencher from the Port of Blyth to the United States to support an offshore wind farm development.

The state-of-the-art T3200 trencher, designed for trenching in hard seabed conditions, was shipped 3,200 miles across the Atlantic. Its mobilisation, including associated equipment such as control rooms, generators, a 12-meter Passive Heave Compensator, and a scissor frame, required precise coordination and execution across multiple disciplines.

Mobilising such a large and complex spread of equipment involved rigorous preparation. Harlyn Solutions relied on Enshore Subsea’s detailed deck plans and bespoke steelwork to manage every stage—from preassembly to testing. Key operations included hotworks, QHSE site management, risk assessments, and collaboration with hydraulic and electrical subcontractors.

The engineering team introduced flexibility into the mobilisation plan to accommodate on-the-fly adjustments. One particularly challenging lift involved the Passive Heave Compensator, which had to be installed with less than 100mm of clearance—a delicate operation requiring simultaneous lifting and skidding.

“Our team of engineers and subcontractors work safely and efficiently to perform this slick mobilisation, dealing with the inevitable clashes and challenges every mobilisation encounters,” said H.Adamson, Managing Director at Harlyn Solutions. “But with great client and vessel interaction, the operation was completed successfully.”

The mobilisation ran around the clock, supported by multiple cranes and dedicated teams handling electrical work and welding. Harlyn also coordinated with specialist partners to ensure maximum uptime and smooth execution.

Mechanical Engineering graduate James, who joined Harlyn in mid-2024 after meeting the team at the Newcastle University Careers Fair, played a notable role. Initially involved in engineering preparations, he soon took on supervisory responsibilities during night shifts. Overseeing lifting operations and managing welders, he ensured on-site work aligned with technical drawings and procedures—ultimately leading shifts independently.

Once the trencher completed its scope offshore, the JD Assister returned to Blyth, where Harlyn carried out the demobilisation in March 2025. The T3200 and all support equipment were offloaded safely, marking the end of the project.

“The planning and execution of the mobilisation and demobilisation were highly efficient,” said Daniel Fraser, Project Manager at Enshore. “Harlyn’s team is professional, knowledgeable, and approachable. Their adaptability and problem-solving approach ensured the process ran smoothly.”