Lifing capacity reaching new heights

AT THE END OF 2019, JAN DE NUL GROUP ORDERED THE FLOATING INSTALLATION CRANE VESSEL LES ALIZÉS. TOGETHER WITH THE OFFSHORE INSTALLATION VESSEL VOLTAIRE, THIS NEW VESSEL WILL BE IN A SUPER-SIZE CLASS OF ITS OWN, CAPABLE of building the newest generaton of ofshore windfarms. Les Alizés, which will be ready in 2022, is equipped with a crane with a lifing capacity of 5,000t and equally impressive lifing heights.

ALL IMAGES COURTESY OF JAN DE NUL GROUP, UNLESS MENTIONED OTHERWISE.

Les Alizés will be mainly used for the constructon of ofshore windfarms, but with her impressive crane she is also extremely suitable for decommissioning ofshore oil & gas platorms. Thanks to her dimensions and impressive lifing and loading capacites, Les Alizés will be able to load out, transport, and install multple units of the largest and heaviest wind turbine foundatons. In additon, as a crane vessel that foats, she will be able to install heavier and larger foundatons into deeper waters and in more challenging seabed conditons.

This vessel investment is a response to the global trend within the ofshore wind energy sector to design and install increasingly larger wind turbines. This new generaton of turbines can be more than 270m high, with blades up to 120m long, sitng on foundatons of up to 2,500t. The ofshore installaton vessels currently available on the market are experiencing great difcultes in installing these new turbines and their heavier foundatons, with their enormous dimensions and installaton weights. The vessel will be built at a shipyard of China Merchants Heavy Industry (CMHI), located in Haimen, Nantong City, China. As a subsidiary of China Merchants Group, this shipyard has a proven track record in supplying marine and ofshore facilites, which gives Jan De Nul Group sufcient confdence in awarding this contract to CMHI.

Les Alizés is specifcally designed for loading, transportng, lifing, and installing ofshore wind turbine foundatons. The main features include a main crane of 5,000t, a deck loading capacity of 61,000t, and a deck space of 9,300m². With these characteristcs, Les Alizés can easily transport the heavier future foundatons, several in one trip, to the ofshore installaton site, with direct benefts in planning, fuel consumpton, and emissions reducton. Unlike Voltaire, Les Alizés does not have four legs to lif itself above the sea surface. It is a crane vessel for foatng installaton, which means that the vessel is not dependent on water depths and seabed conditons. Les Alizés is equipped with a high-performance DP2 system. >>

Photo courtesy of Schottel.

When designing the vessel, Jan De Nul Group took into account the environmental impact. Jan De Nul tackles environmental challenges by focusing on reducing the footprint of its actvites, partcularly on water and air quality, and on climate. Air waste. The second Green Passport label means that all materials and hazardous substances are mapped out during the constructon phase, in order to facilitate the recycling of the vessel when decommissioning.

polluton is one of the greatest threats to public health. Constructon actvites at sea are usually located close to coastlines, large and small ports, and densely populated areas. Jan De Nul Group is aware that, regardless of the choice of fuel or engine technology, the exhaust gases must always be fltered. As one of the world’s leading players in hydraulic engineering, Jan De Nul Group is pioneering in the feld of such an emission treatment. The latest generaton of its vessels is equipped with an exhaust gas fltering technology that complies with the strict European EURO STAGE V guidelines for emissions on land and inland waterways, and so will Les Alizés. Les Alizés and Voltaire will be the frst seaworthy installaton vessels in the world with extremely low emissions (Ultra-Low Emission Vessel, or ULEv for short) and they will also have a Cleanship NDO7 label and a Green Passport EU label. The Cleanship label confrms that the vessel checks and minimises wastewater and all other residual

In July of this year, the main propulsion package for Les Alizés lef the German producton plant in Wismar to reach the CMHI shipyard in China. The full Schotel propulsion package consists of four rudder propellers, two retractable rudder propellers, and two transverse thrusters to ensure optmal propulsion efciency as well as maximum manoeuvrability. The main propulsion system of the crane vessel consists of four electrically driven Schotel Rudder Propellers type SRP 610 – each with an input power of 3,000kW and a propeller diameter of 3.3m – installed at the stern. With this setup, Les Alizés will achieve a maximum speed of 13kn.

To ensure precise positoning in DP mode, two Schotel Retractable Rudder Propellers type SRP 610 R (3,250kW each with a propeller diameter of 3.0m) and two Schotel Transverse Thrusters type STT 7 (2,600kW each with a propeller diameter of 2.79m) are installed in the bow. The retractable units are fted with an 8° downwards-tlted propeller shaf to reduce thruster-thruster and thruster-hull interactons and increase propulsion efciency.

Another milestone that was reached in July of this year is that Jan De Nul Group has selected Imeca for the delivery of a highly advanced electrical Moton-Compensated Pile Gripper for Les Alizés. The tailor-made gripper, with an integrated X-Laboratory guidance and survey system, will allow safe and efcient installaton of next-generaton monopiles with pin-point accuracy. Gripper delivery is planned for the second half of 2022, and this new mission equipment helps to future proof Jan De Nul Group’s foundaton installaton capability. With the constructon of both Les Alizés and the JackUp Installaton Vessel Voltaire well underway, Jan De Nul Group will shortly have the capability to not only safely and efciently install next-generaton foundatons, but also wind turbines (WTGs).

Photo courtesy of Schottel.