Jan De Nul installs cables for TenneT, buys new vessel

Jan De Nul Group has completed the first part of the cable installation works to connect the offshore wind farms Hollandse Kust (noord) and (west Alpha) to the Dutch mainland.

Jan De Nul

The 220-kV high-voltage tests of both sea and land cables for Hollandse Kust (noord) were completed as well, from the onshore substation to the substation located 18 kilometres offshore, the company said.

The cable installation vessel Isaac Newton installed the cables on the seabed. In addition, Jan De Nul used several remote-controlled underwater trenchers and amphibious cranes in the surf zone to bury and protect the cable in the seabed. The Moonfish (pictured below) is one of these trenchers, a Jan De Nul design tailored to the needs of this project.

The Moonfish. Source: Jan De Nul

In the spring, the cable installation vessel Isaac Newton collected the first lot of 90 kilometres of sea cable from LS Cable & System in South Korea. After arriving in the Netherlands, Isaac Newton installed four different sea cables, starting from the beach.

In total, Jan De Nul is installing four sea cables in three installation campaigns. These sea cables will connect the transformer stations of the two wind farms Hollandse Kust (noord) and (west Alpha) to the mainland. Each transformer station will receive two cables, altogether accounting for a total cable length of 235 kilometres.

Jan De Nul still needs to install two more cable sections to connect the future wind farm Hollandse Kust (West Alpha) to the grid. The cable installation vessel Connector will collect the first in South Korea, transport it to the Netherlands, and then install it. Isaac Newton will again be deployed for transporting and installing the final sea cable section.

Located 18.5 kilometres off the west coast, near the town of Egmond aan Zee, the 759 MW Hollandse Kust (noord) wind farm will feature 69 Siemens Gamesa 11 MW turbines set to be fully operational in 2023.

The west Alpha project is also located in the North Sea along the Dutch coast and, when completed, will contribute to over 40 per cent of the Netherlands household energy needs.

The Hollandse Kust Noord grid connection is scheduled to be commissioned in 2023, and Hollandse Kust West Alpha is expected to follow suit in 2024.

New Offshore Support Vessel

Jan De Nul has also signed a contract with Global Marine Systems for the acquisition of the offshore support vessel Global Symphony, marking a further investment in the offshore installation capacities of the Luxembourg-based maritime contractor.

Global Symphony. Source: Jan De Nul

”Jan De Nul has a very modern cable installation fleet, with three large cable installation vessels, supporting trenchers and amphibious cranes,” Wouter Vermeersch, Manager Offshore Cables at Jan De Nul Group.

”Our investment in an additional Offshore Support Vessel, that in legacy of her history and track record will be renamed as Symphony, underlines Jan De Nul Group’s vision to offer the world a solution to the badly needed energy transition. With the success in the Netherlands and the investment in its offshore installation fleet, Jan De Nul validates its expertise in and resolute commitment to this energy transition.”

The Symphony will predominantly be used to support the company’s cable installation activities and will operate as a dedicated trenching support vessel. The recently delivered newbuilt trencher Swordfish will be installed on board the Symphony by the first quarter of 2023.