Heerema Marine Contractors has developed a new method for offshore floating wind installations, deploying its fleet of floating crane vessels.
The company’s Floating to Floating installation method was developed to deliver solutions to industry challenges, such as efficient use of resources like steel and port infrastructure, offshore logistics and maintenance and reaching the required scale and rate of installation.
There are various proposed methods that involve assembling floating foundations (floaters) in port before wet-towing to the field. This presents logistical challenges, as well as there being pressure on the number of suitable harbours.
Heerema has developed an alternative method that does not require a wet-tow and removes the need for marshalling yards.
Using the Floating to Floating installation method floaters can be constructed on land before being dry-towed on a transport vessel to the location.
After arrival, they can be installed using Heerema’s floating installation frame to lift the floaters from the vessel at the location.
Heerema’s floating installation frame submerges the floaters down by weight, removing the need for high-tech ballasting or tensioning systems and reducing installation duration.
The bottom foundation work can be executed in parallel by optimising the capabilities of Heerema’s semi-submersible crane vessels.
Heerema wind business unit director Jeroen van Oosten said: ‘We want to show an alternative solution for installing offshore floating wind, especially targeting some of the bottlenecks for scaling up. We strongly believe that by opening up to new ways of working and collaboration floating wind can reach the potential the industry is looking for.’
By removing time-consuming and highly weather-sensitive wet tows and mooring connections, higher throughput can be achieved on floating wind projects.
The Floating to Floating installation method means floater and turbine campaigns can be decoupled, reducing supply-chain pressure, and resulting in a more efficient process, Heerema said.
The crane-supported floating to floating installation method is built on proven technologies from the oil and gas floating platform industry, allowing for savings of tonnes of steel per floater reducing overall project CapEx.