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: An improved strake for structures that are subject to vortex induced vibrations and motions due to fluid flow around the structure. One embodiment includes a streamliner on the edge of the strake. The streamliner may be added to existing strakes or may be formed at the same time as the strake for extruded strakes. The streamliner reduces vortex induced vibrations and motions of the structure to which the strake is attached. Another embodiment of the invention provides a tension resisting support attached to the strake and structure. The support provides a different load path along the strake than the previously known art for carrying the pressure loading from fluid pressure acting normal to the surface of the strake.

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: An arrangement and method for restraining surge and sway of the barge during floatover of a topside onto a substructure. Roller bumpers provided on the substructure guide the barge during slot entry and exit without the use of secondary mooring lines and restrain sway at the floatover position. Dedicated vertical bearing surfaces are provided on the substructure at the entry to the slot. Resilient bumpers are provided on the barge. The resilient bumpers engage the dedicated vertical bearing surfaces on the substructure and position the barge in the floatover position in the longitudinal direction. A tug boat tows the barge into the slot until the resilient bumpers engage the dedicated vertical bearing surfaces. The tug continues to pull throughout the floatover operation to hold the barge in the floatover position.

Abstract: An improved strake for structures that are subject to vortex induced vibrations and motions due to fluid flow around the structure. One embodiment includes a streamliner on the edge of the strake. The streamliner may be added to existing strakes or may be formed at the same time as the strake for extruded strakes. The streamliner reduces vortex induced vibrations and motions of the structure to which the strake is attached. Another embodiment of the invention provides a tension resisting support attached to the strake and structure. The support provides a different load path along the strake than the previously known art for carrying the pressure loading from fluid pressure acting normal to the surface of the strake.

Abstract: An apparatus and method for pressurizing tubular members of an offshore structure immersed in seawater so that the internal pressure resists the hydrostatic pressure of the seawater. To achieve this internal pressure, compressed air or gas is introduced into the tubular members after the various tubular members are submerged in seawater.

Abstract: A pile driving transition piece. The transition piece avoids the shock loading in the stabbing points of pile driving transition pieces that otherwise would be induced when the pile driving hammer strikes the transition piece. Avoiding the shock loading prevents the characteristic fatigue cracks from forming in the stabbing point and the consequent failure of the stabbing points from rapid growth of the fatigue cracks.

Abstract: A method and apparatus that eliminates the need for a derrick barge to lift the deck into place on a floating offshore structure. A connector is used to connect the transport barge to the floating offshore structure. The connector is a type that allows only relative pitch motions between the transport barge and floating offshore structure in response to sea states acting on the barge and floating offshore structure. The connector is also a type that allows disconnection while large forces are acting on the connector. One or more skidding girders attached to the legs of the deck support the legs of the deck above the skidding surface of the transport barge. A skidding surface on the girders, and complementary skidding surface on the surface of the transport barge and floating offshore structure, allow the deck to be skidded from the barge to the floating offshore structure.

Abstract: A marine connector that facilitates docking of large floating objects during a sea state that produces significant relative motion between the two objects. A toggle nose is mounted on one floating object and a mating device, a toggle nose receiver, is mounted on the second floating object. The toggle nose contains a toggle mechanism that extends and retracts two opposed transverse pins having conical ends. The toggle nose receiver is provided with corresponding conical sockets to receive the ends of the pins.