Mammoet has introduced two major innovations in monopile handling that have improved safety and efficiency during construction of the Baltic Power offshore wind farm, as turbine foundations continue to grow in size and weight.
As offshore wind developments move further from shore in search of stronger and more consistent wind resources, foundation dimensions have increased significantly. Larger diameters and greater lengths are required to withstand harsher marine conditions, while also supporting taller turbines. This trend is placing increasing demands on the lifting, transport and installation equipment used across the sector.
In response, Mammoet has developed a new XXL monopile transport system and the MTC 1600 terminal crane, both designed to handle the next generation of foundations. The company’s XXL monopile transport system, first introduced in 2024, enables the safe marshalling, storage and movement of the largest monopiles now entering the market. Meanwhile, the MTC 1600, deployed on site for the first time, provides a lifting capacity of 1,600 tonnes and is designed to operate in tandem with a second unit to create an efficient, production line-style lifting operation.
Both technologies were used during Mammoet’s work with contractor Van Oord to marshal more than 70 monopiles for the Baltic Power offshore wind farm. Once operational, the project is expected to generate around 4TWh of electricity annually, equivalent to approximately 3% of Poland’s national demand.
Pic: The Mammoet XXL monopile transport systemMammoet handled 78 monopiles as part of the project, ranging up to 1,680 tonnes in weight, 86.3m in length and 9.1m in diameter. Delivered in batches of three by barge to the Port of Ronne, Denmark, the units were initially unloaded using self-propelled modular transporters equipped with the XXL monopile transport system.
The system features hydraulically unfolding saddles that cradle each monopile, allowing them to be lifted safely from their transport supports. Using the combined stroke of the transporters and integrated jacking spacers, the monopiles were transferred to temporary storage bunds. The extended stroke length allowed each unit to be raised by an additional 0.6m, making it possible to place and retrieve larger monopiles despite the deeper indents required to support them.
The system also allows for lower and shorter bunds, reducing the volume of gravel required and minimising civil preparation work on site. Once in storage, the monopiles were later transferred to a plugging station, where they were sealed and tested before being transported to the quayside for load-out.
At this stage, two MTC 1600 cranes worked together to lift the monopiles directly into the water for onward transport by tug to Van Oord’s installation vessel, Svanen, located some 23km offshore near the Polish coast. The tandem crane configuration effectively transformed the quay into a high-capacity heavy lift terminal, enabling efficient load-in and load-out operations.
In addition to monopiles, Mammoet also marshalled transition pieces at the same port using a similar process, although these were handled with a crawler crane rather than the terminal cranes.
Jaap van der Riet, commercial manager at Mammoet, said: “When we were in discussions with Van Oord, it wanted to upgrade the Svanen to have a 3,000t lifting capacity, so the vessel could install XXL monopiles in the Baltics,” he said. “To further support that, we said we would develop cranes and systems that matched this capacity. This is a real strength of Mammoet: if no solutions exist, we develop them, together with our clients, to meet their specific needs.”
Baltic Power, developed by ORLEN and Northland Power, is scheduled to become operational in the second half of 2026. The project demonstrates how advances in heavy lifting and transport technology are enabling the continued growth of offshore wind infrastructure.