They will be built at COSCO’s shipyard in Qidong, China. The two X-class vessels are set to be delivered by 3Q 2024 and 1Q 2025, respectively.
The vessels are expected to have a deck space of 5,600 sq m (60,278 sq ft), a payload of more than 17,600 tons, and main crane capacity of more than 2,000 tons at 53 m (174 ft). The vessels will be able to transport and install seven complete 15-MW turbine sets per load or five sets of 20+ MW turbines.
The design of the two new X-class vessels incorporates Cadeler’s decade of experience as well as detailed client feedback.
Mikkel Gleerup, CEO of Cadeler, said: “Compared to the original specifications of the X-class vessels, our final design includes an upgraded jacking system and main crane. This is to better cater for the wind turbines of tomorrow taking into account the latest input provided from clients and partners.”
To reduce the impact on the environment, the company outlined key deliverables within the vessel building specification which were evaluated as a part of the overall tender process. For example, the company requested criteria such as: minimized emissions, minimized environmental impact, CO2 accounting during the building process, minimized use of hazardous substances, requirement for biodegradable grease and oil in instances with any risk of discharge to the environment, and that the vessels must be recyclable.
Additionally, specific technological improvements are planned for in the new design, the company said. These include a shore power connection which is expected to reduce fuel consumption by up to 15%, fuel efficient engines and optimized engine sizing, as well as a battery pack with capacity to reduce fuel consumption during crane operations and DP maneuvering. The vessels also will include technology for the regeneration of power from the jacking system and cranes.
The project will be located on Dogger Bank 195 km (121 mi) offshore northeast England. The 14-MW turbines are expected be the largest in the world at the time of installation. The wind turbines will be 252 m (827 ft) tall, measured from sea level to the tip of rotor blade, and will have a rotor diameter of 222 m (728 ft).