Unveiling a future-proof cable layer for power interconnectors 

Jan De Nul Group is investing in two newbuild vessels to begin cable laying in 2027 using in-house designs with more transportation and installation capabilities. 

It is preparing the fleet for the future of offshore long-distance power cable laying with these newbuilds, which will be larger and more capable than existing vessels in the fleet. 

Jan De Nul project manager for subsea cables, Arjen van den Bos said these vessels will have three cable carousels for installation of up to three cables in one laying run, which will increasingly be required for further remote, offshore renewables projects. 

These larger ships will also be able to carry more cables for power interconnector installations in ultra-deepwaters, such as across the Mediterranean. 

For example, a future project would involve laying a high-power cable between Egypt and Greece, with around 1,000 km of cable laid in various water depths down to 3,000 m at its deepest point, and in shallow waters to the coastlines. 

“These future projects will need larger vessels and bring new challenges,” said Mr van den Bos. “Our two new vessels will have three carousels, and they are much larger than previous newbuids.” These carousels will each be able to carry 11,000 tonnes of cable. 

Larger ships can carry more AC cables for these longer interconnector projects, resulting in fewer joints and less risk, and they can install three-cable DC systems to connect more remote windfarms, for example in the North Sea or offshore Taiwan. 

These vessels will have tensioners on deck capable of handling three cables to 500 m water depth or one to 3,000 m, and a wheel on the stern, combined with a chute for installations without friction.  

They will also have hybrid and green propulsion, with an energy storage system augmenting a set of five dual-fuel engines, which can run on conventional fuels, biofuels and methanol, and all-electric remotely operated vehicles on board. 

Arjen van den Bos spoke at Riviera’s Offshore Support Journal Subsea Conference in London, UK, on 3 February 2025.