Offshore wind octagon

The offshore wind octagon is a newly developed jacket structure with an octagonal layout based on standardized steel tubes and components, which enables their cost-saving industrial manufacture.

The load-bearing structure comprises an octagonal jacket foundation and tubular tower sections. The eight legs feature horizontal braces at five levels as well as diagonal braces for improved torsional stiffness and demonstrable fatigue resistance. They are fitted in every other field in a helical arrangement around the foundation structure from the top to the bottom level. The diagonal braces counteract the torsion produced by the high torques. The upper section of the jacket structure is connected with a tubular tower. The decisive edge of this design is that it allows standardized industrial production.

Technical Details

Turbine capacity 2 - 6 MW
Tower head mass 150 - 350 t
Hub height Up to 140 m
Jacket height Variable
Steel tube length Variable
Legs - ∅ tubes 914 - 1,016 mm
Braces - ∅ tubes 610 - 660 mm
Total height of load-bearing structure Up to 135 m
Jacket weight Up to 250 t

Advantages of the newly developed structure

  • A radical departure from production methods used until now: series production possible, i.e. short production times
  • Standardized semi-finished products (uniform length / dimensions)
  • Very few different semi-finished products
  • 100% Salzgitter material
  • Automatic welding of joints
  • Standardized mill coating of tubes possible using a state-of-the-art process
  • Variable total diameter (thanks to variably sloping tubes)
  • High reproducibility / close tolerances