The underwater foundation of offshore wind power is mainly composed of the Transition Piece, (TP), the upper structure (Upper Jacket) and the lower structure (Lower Jacket) and other three key steel structures; among them, TP carries the wind turbine tower upward and connects the pipe-frame underwater foundation downward. An important boarding platform for wind turbine operation and maintenance; therefore TP is a very important key component of the underwater foundation and the quality requirements are very high.
