Offshore Wind

Offshore Wind

Harnessing sea wind is the fastest route to a sustainable future - but also the most complex. Managing a global supply chain, ever-expanding turbines and infrastructure designed for other industriesdevelopers must still deliver energy at a viable cost per Megawatt.

Back to

Bringing it together

The offshore wind industry stands at a crossroads. As on land, turbines are growing larger, heavier and tallerapproaching 175m and a combined weight of over five tonnes  but this is only a small part of the story.

The vast size of offshore wind components means they fast outgrow the storage capacity of fabrication yards and ports. What’s more, competition from the oil and gas sector forces wind projects towards container ports and smaller, non-specialist facilities, ensuring space is always at a premium.  

Against this backdrop, fabrication is spreading across the globe, with monopiles, transition pieces and tower sections travelling further and further to reach their destinations. As new countries enter the market, sophisticated just-in-time logistics networks will be needed to ensure ports work efficiently. 

The right modularized construction strategy minimizes the time turbines are stored at port. The right lifting plan means vessels spend less time lying idle. A smart logistics approach helps to connect the two, forming a smooth production line on a global scale. 

This helps wind farms to be constructed at the smallest number of locations, with the fewest possible interfaces, in the largest units – making them faster to build and more cost-effective 

A smooth production line

Fabrication always takes place against the clock. Every day piles sit on supports is a day something else can’t be made; every hour a vessel lies idle costs demurrage; every minute the factory is unproductive still goes on the payroll.

Success here is about how to transfer loads from production to storage, then storage to vessel, as quickly as possible - using as little space as possible. Every second saved pays off hundreds of times over as successive batches go out. 

So, it is vital that modules are designed with their whole lifecycle in mind. A center of gravity that supports vertical storage saves space. The right lifting points allow jackets to be lifted without waiting for custom steel. Shipping in pieces allows for more content local to the project and takes less time.  

We offer a range of handling and marine services, from on-site transportation via SPMT, through a range of specialized equipment such as blade clamps and tailing systems, to complex load-outs including mooring and ballasting. 

Our experts' smart strategies keep load-outs efficient, even as monopiles start to outgrow the largest heavy lift vessels. Through custom handling frames, we help to transfer jackets without modification and move transition pieces while still uprightspeeding up schedules 


Francisco Rodrigues, Global Segment Lead, Offshore Wind 
Francisco Rodrigues, Global Segment Lead, Offshore Wind 

“Offshore wind provides the clearest path towards the carbon-neutral targets of 2030 and 2050. For countries without the shallow water areas and soil types to support fixed-bottom offshore wind, floating wind provides a route to more sustainable energy.  

As more countries enter the offshore wind market, there needs to be a reliable pipeline of projects in place before ports will consider upgrades that are very specific to offshore wind to be worthwhile.  

In the meantime, Mammoet can help by providing the temporary ground strengthening, lifting capacity and other infrastructure needed to get offshore wind projects off the ground.”

Francisco Rodrigues, Global Segment Lead, Offshore Wind 
Francisco Rodrigues, Global Segment Lead, Offshore Wind 

Removing bottlenecks

The size of offshore wind components continues to grow: monopiles of 2,500t are now commonplace – even nacelles can now weigh over 1,000t. These are specialist pieces of equipment that require specific infrastructure to handle.

However, competition from more lucrative oil and gas projects means offshore wind projects may need to consider less well-equipped locations that do not have the required ground strength, storage space or draft. This is a technical challenge and also puts pressure on schedules, as working envelopes tighten. 

Even at ports used to serving offshore wind, with components this large the pressure to use space efficiently is always on. Vessels must be kept constantly working to maximize cost-effectiveness; documentation must be prepared promptly; components must arrive precisely on time at congested sites. 

We act as a single point of contact from factory or storage to the installation vessel, reducing the number of interfaces experienced during each project, which in turn lowers the risk of delays. From interaction with shipping agents, through stevedore management, to lashing and sea fastening, we run a well-oiled machine.  

Where infrastructure can be developed, we take a long-term approach, helping to create a lasting legacy to serve current and future wind projects. Where it can’t, our engineers can temporarily strengthen the quay to support offshore wind marshaling using technologies such as Enviro-Mat.

Robert Eykhout, Regional Commercial Lead, Offshore Wind 
Robert Eykhout, Regional Commercial Lead, Offshore Wind 

“The United States is entering the offshore wind market in a big way. Under the current administration, it has rejoined the Paris Agreement and has a handful of projects already in the pipeline; totaling hundreds of units. 

This is a significant development that will be felt strongly in the region, as facilities, vessels and workers must be found to meet demand. But the impact of this will also be felt globally; through higher-volume fabrication and more global project planning.  

Mammoet’s decades of experience in planning complex, modular projects across countries and continents will help to make this happen”.

Robert Eykhout, Regional Commercial Lead, Offshore Wind 
Robert Eykhout, Regional Commercial Lead, Offshore Wind 

Reaching high

Seeking stronger and more reliable winds, turbines and piles are increasing in size, height and weight. Reaching up to 175m and over a combined five tonnes, they are growing beyond the ground strength of some ports, and the reach of many cranes. 

During pre-assembly, keeping the installation vessel waiting is not an option. So, components must be stored for easy access, as close as possible to the water’s edge, and with as few time-consuming transfer or upending maneuvers as possible. 

Assembling modern offshore wind turbines also requires some of the world's largest cranes - but at local or container ports, infrastructure may need to be temporarily strenghtened for work to proceed. This allows more of the project to take place in the host country, and from operational expenses. 

With the market’s largest equipment fleet, Mammoet can mobilize a wide range of hydraulic saddles, blade clamps and transport frames to any worldwide location, allowing components to be stored compactly as manufactured, or closer to ground level. This quickens on-site transportations and ties up less space. 

The large radius of our PTC and SK cranes move lifting away from the quay edge onto surer ground, while their giant hook heights allow turbine assembly to take place on or next to the quay, where it is most efficient. Where needed, our experts design transfer and ground strengthening techniques that allow projects to proceed, whatever the location.


Antoine Lefevre, Sales Manager, Offshore Wind 
Antoine Lefevre, Sales Manager, Offshore Wind 

“In the short term, fabrication of monopiles, transition pieces and turbines will continue to take place around the North Sea in Europe. However, increased demand will result in more diversity. 

Firstly, we will see additional fabrication taking place elsewhere in Europe. Later, facilities will be opened in North America. As the floating wind market matures, more fabrication will take place in Southeast Asia, as we have seen in other sectors. 

Success will ultimately depend on managing this complex supply chain, with projects touching most continents in some way.

Mammoet’s experience, gained from the world’s largest modularized construction projects, will allow the offshore wind industry to simply re-deploy expertise that already exists and also create value by developing new methods for handling, assembling and possibly launching components in the future”.

Antoine Lefevre, Sales Manager, Offshore Wind 
Antoine Lefevre, Sales Manager, Offshore Wind 

All at sea

Maintenance activities have been taking place at sea for many decades, across the energy sector. While many aspects of this are transferrable, one is not: where in other sectors there are hundreds of locations, in offshore wind there will be many thousands.

As offshore wind farms age, the likelihood of maintenance events will increase. Delivering the right equipment to the repair location will be a challenge in itself. 

Intense competition will develop for the use of crane vessels; many of which will be too short to repair turbines at sea in any case. The significant technical challenge of performing repairs while floating is another significant issue. 

Mammoet is innovating to develop solutions that will help maintenance to take place more easily. By utilizing gantry lifting systems attached to the turbine itself, items up to 200t can be lifted to and from the nacelle, facilitating repair of motors, gearboxes and generators at sea. 

Lifting systems using the turbine for support allow operators to respond more quickly to incidents, storing maintenance equipment locally for re-use. In this way, uptime is maximized, helping each offshore wind farm to deliver the greatest possible return on investment 

Bram van Oirschot, Manager Sales, Conbit 
Bram van Oirschot, Manager Sales, Conbit 

“We estimate that 25% of offshore wind turbines will have a maintenance incident during their lifetime. Moreover, in floating wind, there is some uncertainty on how constant movement will affect the reliability of turbine components.  

A large part of the operating expenditure of offshore wind farms will focus on repair of turbines. While it is inevitable that there is some randomness involved, innovative solutions can reduce the time taken to resolve incidents.  

Custom lifting gantries are ideally suited to the offshore wind environment, where local port infrastructure may not be ideal, and maintenance events may be spread over a large geographical area”.

Bram van Oirschot, Manager Sales, Conbit 
Bram van Oirschot, Manager Sales, Conbit 

Powering the future

Floating wind offers the fastest route to 2030 emissions targets. Building bigger and in greater volumes than ever before, it faces the challenge of creating a smooth production line from design to water: lowering energy costs and increasing project viability.

The sheer space required to build floating foundations will be a challenge for existing fabrication facilities; a fact that is likely to open the market to new entrants across the globe. Floating foundations are expected to grow to a footprint of 10,000m2 and 16,000t in weight, so need considerable infrastructure to handle.

As the sector matures, these modules will need to be fabricated, transported and launched in locations all over the world. This will require feats of engineering never before seen in the renewables sector – and further intensify pressures on time and space.

As turbines reach higher, innovations such as the SK6,000 will allow assembly to continue next to the quay, where it is most efficient. When maintenance events occur, our gantry solutions allow for fast repair at the turbine site, avoiding downtime while a suitable crane vessel is found.

Our offshore services team has transferred some of the world’s largest structures between land and sea; constantly innovating to find a way into the water that is most efficientsafe and cost-effective.

Click here to learn more about our floating wind services.