Jan De Nul bolsters fleet

4C Offshore | Tom Russell
By: 25/11/2022 Jan De Nul

Jan De Nul revealed that it has signed a contract with Global Marine Systems Ltd. for the acquisition of the Offshore Support Vessel,
Global Symphony. The Offshore Support Vessel will be renamed Symphony and will become the ‘home base’ of Jan De Nul’s in-house designed and built Trenching ROV.

Built in 2011, the Symphony has an extensive 1,400m² deck space and is amongst others equipped with two 150 HP work class ROV systems and a 150 tons AHC crane.

The vessel will predominantly be used to support cable installation activities and will operate as a dedicated Trenching Support Vessel. Jan De Nu's recently delivered newbuilt trencher Swordfish will be installed on board of the Symphony by the first quarter of 2023.

Last week (17 November 2022), Jan De Nul Group completed the first part of the cable installation works to connect the
Hollandse Kust (Noord) and (West Alpha) wind farm grid connection projects to the Dutch mainland. Also the 220-kV high-voltage tests of both sea and land cables for Hollandse Kust (noord) were successfully completed, from the onshore substation to the substation located 18km offshore.
Wouter Vermeersch, Manager Offshore Cables at Jan De Nul Group: “The Hollandse Kust (noord) and (west Alpha) project showcases our expertise in cable installation works. Jan De Nul has a very modern cable installation fleet, with three large cable installation vessels, supporting trenchers and amphibious cranes. 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 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 is one of these trenchers, a Jan De Nul design tailored to the needs of this project.

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

Two cables were laid in one length on the seabed, all the way to the transformer station of Hollandse Kust (noord).

For the connection to the transformer station of Hollandse Kust (west Alpha), the Isaac Newton installed the first 8km of both sea cables, starting from the beach.

Next, the trencher Moonfish set to work, burying and protecting the sea cables in the seabed.

In the first phase, the Moonfish buried the first section of the two Hollandse Kust (noord) sea cables in the seabed, from the beach up to 3km offshore, at a depth of about 6 to 8 metres.

From three kilometres offshore, the submarine vehicle UTV1200 took over, laying the cable up to the transformer station. This 'offshore socket' is located 18km off the Dutch coast.

After the summer high season, in October, Jan De Nul completed this first installation campaign by burying the two cable sections for Hollandse Kust (west Alpha) from the beach up to 3 km offshore.

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, all together accounting for a total cable length of 235km.

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

For more information on offshore wind farms worldwide, click here.