11.7% LCOE reduction
“The component based design not only allows for extremely high production rates, but also distributed manufacturing and local jobs”
Manufacturing
In 2022 OWLC, together with our engineering partner Arup and construction partner Fuchs-Europoles, conducted manufacturing and assembly testing of the Gravity Tripod™.
The project went from a blank piece of paper, through a design, manfuacturing design, homologation, creation of the formwork, casting of the components, and assembly of the structure in an incredibly short period of only 3 months. The assembly testing demonstrated an unparalelled produciton rate for the structure, in less than 4 hours (over two days) the structure went from pre-cast components to fully assembled. On the first day the base components were assembled, pre-tensioned, and the seams were grouted, in only 3 hours. On the second day the structure was post-tensioned to the full working load, and the columns installed in only 45 minutes! Our construction modelling shows that the overall structure is expected to be able to be assembled in 3 days. With a medium sized port being able to work on 12 structures at any one time we expect to have a production rate of 4 structures per day (a rate that corresponds to our expected installation rate.)
THE GRAVITY TRIPOD’S MANUFACTURING ADVANTAGES ARE
- Use of Concrete
- Component Based Design
- Mass Manufacturing
- Speed of Assembly
USE OF CONCRETE
The Gravity Tripod uses concrete as opposed to steel. Not only does this mean the structure has a lower embedded carbon content than competitors, but also as a low cost material with less commodity price fluctuation benefits projects through mitigating their supply risk and hedging position.
In addition, as a concrete structure there is an extensive supply chain already in place. As an example the UK consumes 90m tonnes of concrete a year, just 3% of that is enough to supply all of Europe’s offshore wind substructure needs with the Gravity Tripod™.
COMPONENT BASED DESIGN
As the Gravity Tripod™ is manufactured from pre-cast concrete components, it is ideally suited to developing local supply chains. Manufacturing of components can be dsitributed across multiple sites creating employment in deprived areas and allowing smaller ports to feed the fast growing offshore wind industry. Meanwhile, the ready availability of concrete as a material, as well as the skills and loabour required to work it, means there are no restrictions to the Gravity Tripod™ creating local jobs.
MASS MANUFACTURING
The Gravity Tripod™ is designed for mass manufacture. The key components, the concrete columns, are made with a spin-casting technique that is fast and efficient. With a spinnning machine able to make 1 column per day per mold scaling of manufacturing is easy, and cost effective.
SPEED OF ASSEMBLY
Not only does the Gravity Tripod™ be manufactured locally, it can also be assembled close to the project where it is to be installed. The post-tensioned design means that the structure is simple to assemble, with even medium sized ports having space to work on 12 structures at any one time a produciton rate of 4 per day is expected, mirroring the installation rate.
