Abstract: A load out and float off method for a spar type structure or another structure such as a deck. The invention enables the load out and float off of a large diameter spar using existing Heavy Lift Vessels (HLV's). A U-shaped tank (U-tank) is utilized to artificially extend the length of the HLV and provide supplemental buoyancy to help lift the spar off the land ways. The U-tank provides supplemental buoyancy and water plane area to float the spar off the HLV. After HLV departure the U-tank is moved and placed beneath an adapter frame on the spar's hard tank. The U-tank is ballasted upward to reduce the hard tank draft and have the strake tips clear the channel bottom. The spar can then be brought alongside the fabrication yard quay for additional work and then towed down the channel to the open sea.

Abstract: A load out and float off method for a spar type structure or another structure such as a deck. The invention enables the load out and float off of a large diameter spar using existing Heavy Lift Vessels (HLV's). A U-shaped tank (U-tank) is utilized to artificially extend the length of the HLV and provide supplemental buoyancy to help lift the spar off the land ways. The U-tank provides supplemental buoyancy and water plane area to float the spar off the HLV. After HLV departure the U-tank is moved and placed beneath an adapter frame on the spar's hard tank. The U-tank is ballasted upward to reduce the hard tank draft and have the strake tips clear the channel bottom. The spar can then be brought alongside the fabrication yard quay for additional work and then towed down the channel to the open sea.