First of two cable-lay vessels that will be the world’s largest launched in China 

The company will use Fleeming Jenkin – which has a capacity of 28,000 tonnes – to install subsea cables for the renewable energy market. Delivery is scheduled for the second half of 2026. The launch took place at CMHI Haimen shipyard in China.

The new cable-lay vessel is designed to install longer, heavier cables in water depths of up to 3,000 m. In addition to Fleeming Jenkin, Jan De Nul is also building a second cable-laying vessel, a sister vessel William Thomson.

Fleeming Jenkin will have three cable carousels and a large hold for fibre optic cables. It will be capable of laying up to four cables simultaneously. Two carousels are mounted on deck, with a third below deck. The combined cable-carrying capacity of 28,000 tonnes is twice the capacity of any other cable-laying vessel currently on the market.

On the aft deck, the vessel will be equipped with a chute and a cable-laying wheel. In combination with the tensioners, the chute allows installation of cables in shallow water, while the cable-laying wheel makes installation at great depths more efficient. The tensioners enable the vessel to handle and control cable tensions up to 150 tonnes.

The new vessel and its sister ship will also be ‘green’ vessels. Described by Jan De Nul as ultra-low emissions vessels (ULEvs), they will have an advanced dual exhaust filter system which removes up to 99% of particles from emissions using a diesel particulate filter and a selective catalytic reduction system for nitrogen oxides. The system also significantly reduces exhaust gas pollutants. The engines of the vessel can run on biofuel and green methanol, reducing CO2 emissions. The ULEv concept means the vessels comply with European Stage V emissions standards for inland waterway vessels and NOx emissions will be reduced to such an extent that they meet even stricter EURO VI emissions limits. The hybrid power plant on board will also help to reduce CO2 emissions and ensure optimal fuel usage. It combines the generators with a 2.5-MWh battery and drive technology, designed for peak shaving, load smoothing, spinning reserve and optimised engine loading.

Once operational, Fleeming Jenkin will start work immediately on its first assignment, TenneT’s 2GW Program, which will see the grid operator build a new grid connection for offshore windfarms that each transmit up to 2 GW of power, more than double the capacity of existing connections.

Fleeming Jenkin will install the export cables on four of the 2-GW connections, bundling and laying four cables together. In total, the vessel will install more than 2,800 km of cable.

Jan De Nul director subsea cables Wouter Vermeersch said Fleeming Jenkin “combines all the cable installation expertise we have built up over the past 15 years. The result is a vessel that operates very efficiently, reducing the cost of projects and their environmental footprint.”

He said Fleeming Jenkin and William Thomson “are the best vessels on the market for the installation of cables for interconnectors.”

Jan De Nul also recently ordered a new subsea rock installation vessel, George W Goethals, that will install rock to protect subsea cables at depths of up to 400 m.