Heerema Fabrication Group: Dutch craftsmanship for offshore wind in the North Sea
Heerema is a Dutch offshore company with internationally recognised expertise in the engineering, fabrication, transport and installation of heavy offshore structures.
Heerema comprises three independent divisions: Heerema Marine Contractors in Leiden, with overseas branches; Heerema Fabrication Group in Vlissingen and Poland; and Heerema Engineering Solutions in Delft. Depending on the project, these divisions work closely together or are engaged separately. Heerema has a long history of complex offshore projects in the North Sea, where the company has played a key role for many years in the construction, transport and installation of heavy offshore structures. Today, that experience forms a strong foundation for Heerema’s growing role in offshore wind energy. This development is in line with the energy transition and the increasing political and social focus on renewable energy.
Developments in offshore wind
The development of offshore wind farms shows a clear trend: farms are getting larger, turbines more powerful and locations are situated further and further offshore. Whereas a few years ago, 8 to 10 MW turbines were the norm, capacities in the region of 14 to 15 MW are now becoming increasingly common for new projects. At the same time, rotor blades are getting longer and towers taller, further increasing the energy yield per turbine. To transmit this generated energy, an offshore substation is required for each wind energy area. Such a substation collects the electricity from the wind turbines, steps it up to a higher voltage level and enables transmission to the mainland. The substations rest on heavy steel foundation structures anchored to the seabed. These structures, also known as jackets, can weigh more than 10,000 tonnes and are one of Heerema Fabrication Group’s core areas of expertise.
Collaboration with Seatrium
Heerema Fabrication Group in Vlissingen has been selected by the Seatrium consortium and GE Vernova to fabricate three jackets as part of TenneT’s 2GW programme: IJmuiden Ver Beta, IJmuiden Ver Gamma and Nederwiek 2. These jackets form the foundation for offshore converter platforms designed to transmit renewable electricity from wind farms in the North Sea to the Dutch high-voltage grid. Heerema Marine Contractors will then handle the transport and offshore installation of the jackets. This combines Heerema’s onshore fabrication capabilities with its offshore installation expertise.
The collaboration with Seatrium is intensive. Seatrium staff are based at Heerema in Vlissingen to monitor the project’s progress, ensure coordination and liaise directly with the project teams where necessary. This close collaboration is essential for projects of this scale, where engineering, planning, quality, safety and logistics must be closely aligned.
The construction of a jacket
The construction of a jacket typically takes 12 to 24 months, depending on its size and technical complexity. No two jackets are the same. The design is determined, amongst other things, by the type of platform to be installed on it, the seabed conditions, water depth, currents and the specific conditions at the offshore location. Engineering can be carried out by Heerema itself, but for some projects it is handled by specialist external parties. At the shipyard in Vlissingen, work is often carried out on several jackets simultaneously, with the various projects at different stages of the construction process.
Once a jacket is ready, it is driven onto a pontoon and transported to the offshore location. There, the structure is lifted by a crane vessel, precisely positioned and anchored to the seabed using foundation piles. The scale of this operation is vast, but the precision with which the work is carried out is just as important: after all, the jacket forms the basis for a critical component of the future energy infrastructure.
“To an outsider, they might all look big, yellow and made of steel. But if you ask around here, every jacket is unique.”
Richard Spronk, CEO of Heerema Fabrication Group
Independent counter-guarantee
For this transaction, Heerema Fabrication Group took out a standalone counter-guarantee with Atradius DSB. This counter-guarantee provides the bank involved with financial security and ensures that existing credit lines remain available to the company. In this way, the arrangement supports the financial flexibility required for large-scale international projects.
The North Sea as an energy region
The North Sea is one of the most suitable areas in the world for the development of offshore wind energy. The combination of relatively constant winds, available space and proximity to major energy consumers makes the area strategically important for the European energy transition. As technology continues to advance, even locations that are currently too deep or too complex may become economically viable in the future.
According to Richard Spronk, it is precisely this combination of industrial scale, technical development and social relevance that makes offshore wind so attractive: “It is a very interesting market and, in terms of development, it is particularly valuable to be part of it.”
Bob Barre - Senior Underwriter
Monique Duns - Marketing & Event Officer