Lashing for wind farm installation

The growing demand for offshore wind energy means higher stakes, larger components, and increasing pressure on project teams. The right equipment makes all the difference, so when Heerema Marine Contractors started using sea-fastening chains made with Dyneema^®, the results were clear to see.

Managing a demanding offshore environment

Led by German renewable energy company Parkwind Ost GmbH, Arcadis Ost 1 is a major offshore wind development project in the Baltic Sea, located in German waters near the island of Rügen. Installation of the first 24 wind turbines was completed in April 2023, adding 257 Megawatts of power to the European grid.

Heerema Marine Contractors was selected for the project thanks to a revolutionary new method of turbine installation called the RNA method, which involves the use of a floating offshore installation vessel. However, the method relies on the ability to safely barge-transport heavy wind turbine components between the yard and the vessel. And the components need to be sea-fastened quickly and reliably.

Solution found in DoNova^®PowerLash chains with Dyneema^®

Traditionally, Heerema used steel plate welding and wedges for sea fastening these components on unmanned barges. However, synthetic or textile chains offered advantages over the previous method, which took 48 hours to be completed for welding and inspection release by surveyor. In contrast, synthetic chains only needed 1.5 hour of lashing time for 3 nacelles with 12 chains each, directly followed by inspection and release.

This productivity improvement became possible due to the avoidance of time-consuming welding, the use of existing lashing points, the lightweight of synthetic chains, and their easy surveyance. Next to this, their improved ergonomics make them safer and easier for workers to handle, while also preventing dents and scratches on the wind turbine components.

For Heerema, the key was to find a solution that would maximize speed and efficiency. The Heerema team had previously incorporated Dyneema®, the world’s strongest fiber™, in their mooring ropes and lifting slings. Additionally, in 2020, a team member involved in the Arcadis Ost 1 project successfully utilized synthetic chains on a project in Taiwan. This track record convinced them to use DoNova® PowerLash chains with Dyneema®, manufactured by Dolezych, for the Arcadis Ost 1 project.

The chains consist of multiple layers of Dyneema^® fiber webbing and their unique construction makes them significantly lighter and more flexible than steel chains. As a result, heavy objects such as wind turbine nacelles can be safely and easily secured to the barge deck without the need for a large crew.

Similarly, the superior flexibility of DoNova^® PowerLash chains with Dyneema® makes them easier to manoeuvre in tight spaces – another key requirement when working in confined offshore environments.

“Safety and efficiency were paramount throughout the project. We needed to move components quickly between land and sea without compromising the well-being of the team."

HMC representative, Arcadis Ost 1 project

The need for speed

The biggest breakthrough for the Arcadis Ost 1 project team was speed as the classical alternative to time consuming plate welding, would have been to use steel wire or steel chain lashing. Thanks to their light weight DoNova® PowerLash chains with Dyneema® cut the time needed to connect and disconnect the chains by about one-thirds, saving priceless minutes. In addition, the significant weight savings means only one person is needed whereas with steel lashings normally more manpower is required. Also, with synthetic chains no transport equipment is necessary, such as pallet trolley or fork truck, since one person can easily carry chain sets.

“On a major project like Arcadis Ost 1, every minute counts,” explains Heerema. “Being able to accelerate the sea fastening means we can speed up the transport preparation, so that the transportation barge is ready whenever the offshore vessel calls. Also, when the transport barge arrives offshore, the offshore crew can remove the sea fastening efficiently, cutting critical time for the component transfer”. During this transport release, surveyors like ABL Group and Marine Warranty Surveyors were present.

Smoother, faster and safer handling translates into tangible financial benefits for the team: “The cost-benefit ratio of using DoNova^® PowerLash chains with Dyneema® is certainly less than one. Our investment has, by far, already been paid for itself."

And this is just the beginning. "As the energy transition accelerates, we're seeing the components used in renewable energy projects get bigger and heavier,” adds Heerema. “We now have a solution that can meet the dual requirements of speed and safe, delicate handling by using chains made with Dyneema® fiber.”