The wind turbine generator ( WTG ) components will be transported from the WTG suppliers sites or marshalling sites to the wind farm offshore locations by feeder vessels, and transferred to the deck of the wind turbine installation vessel (WTIV) by the WTIV heave-compensated cranes. The wind turbine generators (tower structure, nacelle, and blades) will be fully assembled on deck of the WTIV and thereafter installed on top of floating- or bottom-fixed substructures, at offshore locations, in tandem lift operations (2 x 2500 T capacity).