High spec installer is designed with next-generation turbines in mind

A new type of high-capacity installation vessel has been ordered that is designed expressly to install the upcoming generation of larger, taller offshore wind turbines

Jan De Nul Group has placed an order at Cosco Shipping Heavy Industry in China for a new type of installation vessel for the offshore wind industry. The vessel, to be named Voltaire, will be the company’s third of this type, but will be significantly more capable than its existing installation units.

With a crane capacity of more than 3,000 tonnes, the jack-up vessel is due to be delivered in 2022 and is designed to install next-generation large offshore wind turbines. It will also be deployed in the offshore oil and gas industry, primarily for decommissioning offshore structures.

Jan De Nul offshore director Philippe Hutse said of the vessel, “On delivery, Voltaire will be capable of efficiently installing the next generation of offshore wind turbines and foundations. This investment is a logical step forward in the development of our offshore wind capacities. Our third jack-up vessel will enable us to cope with the increased number of offshore wind projects worldwide.”

In addition to the 3,000-tonne capacity crane, the vessel will have a payload of approximately 14,000 tonnes and accommodation for 100 people. It will have four legs to lift itself out of the water and a DP2 dynamic positioning system.

Compared to Jan De Nul’s other jack-up vessels, Vole au vent and Taillevent, Voltaire has almost twice as much deck space. The new vessel will have a length overall of 169.3 m (181.7 m including helideck) and breadth of 60 m with a maximum draft of 7.5 m. It will have a deadweight of 21,500 tonnes, maximum payload of 14,000 tonnes, and a 7,000-m³ cargo deck strengthened to 20 tonnes/m². With jack-up legs of 130 m in length it will be capable of operating in a water depth of approximately 80 m.

Voltaire will also be an environmentally friendly vessel that will comply with Euro Stage V regulations. The ship will run on gasoil but will be fitted with an advanced exhaust gas treatment system using a selective catalytic reduction system and diesel particulate filter.

The vessel’s machinery will take the form of four diesel engines each of 3,535 kW and four each of 2,650 kW, plus a 600-kW emergency generator. The main propulsion will be based on a quartet of azimuthing thrusters, each of 3,000 kW, complemented by two retractable thrusters, each of 2,600 kW and two bow thrusters, each of 2,600 kW. This will give Voltaire a maximum speed of 11.5 knots.

Huisman has been awarded a contract for designing, engineering, constructing and delivering the main crane for Voltaire, a crane that will be unique in its size, capacity and novel features.

Apart from a lifting capacity of 3,000 tonnes it will have an unrivalled lifting height, which will be important given the growth in the dimensions of offshore wind turbines. Existing installation vessels are already being challenged by this growth in the size and height of the turbines they need to install and by the increasing dimension of the foundations they require. The new crane will enable Jan De Nul to handle existing and upcoming larger turbines.

Huisman said the leg-encircling crane will be the largest ever installed on a wind turbine installation vessel and, together with its fly-jib, will have the highest lifting height of a crane of its type in the world.