Jan De Nul has unveiled William Thomson, the second of two subsea cable-laying vessels under construction.
The vessels have a cargo capacity of 28,000 tonnes and a length of 215 metres, making them the largest of their kind, according to Jan De Nul.
These cable-laying vessels are designed for installing subsea cables, suitable for depths up to 4,000 metres. Their large capacity allows them to carry longer cables, reducing the need for multiple subsea connections.
Compared to others, these vessels require fewer return trips for cable loading, decreasing costs and environmental impact while improving cable quality.
William Thomson’s sister vessel, Fleeming Jenkin, launched in October 2025, is set for delivery in late 2026. William Thomson is expected to be operational in the first half of 2027. Both vessels were designed by Jan De Nul’s experts.
Wouter Vermeersch, Director Subsea Cables Offshore Energy at Jan De Nul, stated, “The William Thomson and its sister, the Fleeming Jenkin, showcase our expertise in cable installation, being the highest-performing vessels on the market.”
First Stop: TenneT Offshore Grid
Upon becoming operational, Fleeming Jenkin and William Thomson will embark on their first projects.
The initial assignment is the 2 GW programme by TenneT, the grid operator in the Netherlands and parts of Germany. This initiative introduces new grid connections for offshore wind farms, capable of handling up to two gigawatts, enhancing offshore wind energy’s efficiency and affordability.
For this programme, the vessels will install over 2,800 kilometres of 525 kV DC cables for four different grid connections.
In 2028, one vessel will also be used to install three AC cables connecting the Princess Elisabeth Island to shore. This energy island project, a joint venture for grid operator Elia, will bundle cables from Belgium’s second offshore wind zone, strengthening interconnections among North Sea countries.
Original Story at www.offshorewind.biz