Offshore Structures

Svend Ole Hansen ApS has been a consultant regarding different wind engineering aspects of many offshore structures.Examples of services provided for some of these offshore structures are:

Horns Rev I

Offshore wind farm located 14 kilometres off shore in the North Sea. A helicopter hoist at a wind turbine located at Horns Rev I was experiencing fatigue damages due to the air turbulence occurring in the wake of the turbine rotor. Contemporary field measurements of wind and accelerations were carried out. Data from already installed Strain Gauges was used in the analyses. A set of TMD dampers were customized to minimize the vibrations and avoid future fatigue damages. Client: Vattenfall

Walney Offshore Wind Farm 1 & 2, Offshore Substations

Offshore wind farms located 15 kilometres off shore in the Irish Sea, England. The wind farms Walney 1 and 2 each consist of one offshore substation that connects the array cables from 51 wind turbines to the onshore electrical grid. First phase of the wind farm (WOW 1) started producing power in February 2011.  Svend Ole Hansen ApS has assessed the wind loading on the Substation topside structure as well as investigated vortex induced vibrations (inline and cross-flow) on the Substation substructure Jacket leg and bracing members. Further load coefficients for drag and mass coefficients for closely spaced leg and J-tube members were determined. Client: ISC Consulting Engineers A/S

Gorm D Flare Structure

The Gorm Field is located in the Danish part of the North Sea. The Gorm D flare structure raises 91 m above sea level. The buffeting load on the flare structure was investigated in order to provide an improved basis for estimating extreme wind load and fatigue damage. Full scale strain measurements combined with model scale wind tunnel measurements was carried out. The measurement results were compared with theoretical buffeting results. The measured and theoretical results were presented according to the Eurocode. Client: Maersk Oil and Gas

Jack-ups, vibrations of structural members

The leg structures of offshore rigs may be several hundred meters long, which makes the rigs capable of operations on depth below a hundred meter. Investigations have been carried out at a particular offshore rig located at a water depth of approximately 80 meters in the Norwegian part of the North Sea.Violent vibrations of members in the leg structures of the rig have been investigated by extensive field measurements of accelerations and strains.  Varies solutions were investigated and a customized solution performed. Filling the susceptible tubes with a concrete medium reduced the vibrations to a minimum.