Provides access to, from, and within the substructure for personnel and equipment. Accommodates ancillary equipment.
What it costs
About £30 million for a 450 MW floating offshore wind farm.
Who supplies them
Hutchinson Engineering, Kersten, Smulders, Vallourec and Wilton Engineering.
Secondary steel elements on the floating substructures used at the Kincardine project. Photo of the Kincardine Offshore Wind Farm project courtesy of Principle Power.
Examples of secondary steel components include:
- Boat landings
- Personnel access ladders
- Work platform
- Internal platforms and walkways
- External walkways
- Baffles to control the movement of water (ballast) and noxious gases (due to internal component corrosion), and
- Support structures for sacrificial anodes.
Secondary steel is normally subcontracted to a fabricator which does not have the high overhead costs of the fabricator of the primary structure.
Advances in personnel access systems, such as walk-to-work gangways or systems which lift personnel from a vessel, may avoid the need for boat landings.
Aluminium, fibre glass, or concrete may be used instead of steel for some components. For example, pre-cast concrete work platforms are used for some fixed offshore wind projects.