Method of construction, installation, and deployment of an offshore wind turbine on a concrete tension leg platform

A method of constructing and deploying a wind turbine generator (WTG) unit and gravity anchor in open water, comprising the steps of:

• positioning a construction and deployment barge adjacent a staging dock;
• positioning a slip form in a central portion of said construction and deployment barge, said construction and deployment barge having a wing wall at each corner;
• positioning a layer of timber of a selected thickness beneath a WTG foundation prior to slip forming same and deflecting the load of said WTG foundation due to a difference in rigidity of said WTG foundation and said construction and deployment barge;
• slip forming said concrete WTG foundation on said construction and deployment barge prior to leaving said staging dock;
• mounting a tower on said WTG foundation;
• mounting a WTG on said tower, said WTG including a nacelle with a hub and a plurality of blades extending therefrom defining the WTG unit;
• transporting said WTG unit to a deployment site with a first tug or with a second tug;
• pumping a selected amount of sea water into said wing walls thereby partially sinking said construction and deployment barge to a selected draft permitting said WTG unit to be floated off of said construction and deployment barge in a stable free floating condition;
• positioning said free floating WTG unit off of said construction and deployment barge;
• pumping sea water into said WTG foundation ballasting same with said sea water to a selected operating draft;
• attaching a tension leg from at least one gravity anchor to said WTG foundation;
• tightening said tension leg from said at least one gravity anchors with equal tension by pumping said sea water from said WTG foundation;
• and
• tightening said tension leg to a selected design load by applying compressed air to said WTG foundation thereby removing a selected amount of said sea water.