Multi hull vessel with mechanical systems to facilitate safe transfer of cargo by crane to and from vessel in high waves

Abstract

The subject invention is a design of marine cargo vessel with added mechanical equipment specifically designed to minimize dangerous motions of the vessel induced by high waves while the vessel is being loaded or unloaded from fixed platforms (bottom supported or tension leg) at sea or on inland waters. The vessel uses three means of reduction of such induced motions, which have not before been combined for this purpose. These are a small water plane area multiple hull design, rapid ballasting while loading and unloading, and vertical thrusters.

Description

UNITED STATES PATENTS[0001]Patent NumberKind CodeIssue DatePatentee2,889,795A1959 Jun. 9Parks3,224,401A1965 Dec. 21Kobus3,273,526A1966 Sep. 20Glosten3,318,275A1967 May 9Field3,391,666A1968 Jul. 9Schuller3,616,773A1971 Nov. 2Lloyd3,835,800A1974 Sep. 17Lloyd4,167,147A1979 Sep. 11Bergman5,282,763A1994 Feb. 1Dixon6,761,124B12004 Jul. 13Srinivasan9,896,159B12018 Feb. 20Stackpole et al.BACKGROUND—PRIOR ART[0002]The field of the invention is related to the safe transfer of cargo from a floating transport vessel to the deck of a bottom supported, or tension leg structure (called fixed structure hereafter) at sea or on inland waters using a crane, where this crane is generally mounted on the fixed structure. A fundamental technical problem with doing this safely is that a typical cargo vessel will move violently due to waves in rough water conditions, while the fixed structure holds still. This can result in very hard to control and dangerous collisions between the cargo load suspended from ...

AI Technical Summary

Benefits of technology

This approach significantly reduces vessel motions during cargo transfer in rough seas, enhancing safety and minimizing damage to property and personnel by stabilizing the vessel and reducing the risk of accidents.

Problems solved by technology

A fundamental technical problem with doing this safely is that a typical cargo vessel will move violently due to waves in rough water conditions, while the fixed structure holds still.

This can result in very hard to control and dangerous collisions between the cargo load suspended from the crane and the deck or other cargo on the supply vessel.

People have been seriously injured and some killed by such accidents.

Thus, this technical problem cannot practically be gotten around by waiting for better weather.

The problem with motion of the floating vessel with respect to the fixed structure is that these motions can and have caused damage of property or injury or death to crew working on either.

Where the twin hulls are primarily underwater, they are commonly called pontoons, this design as depicted uses pontoons, but need not.2. Lifting or lowering a large mass off or on to the vessel with a crane could—if done badly—tend to induce a large heave and pitch / roll motions.

These can be minimized using ballast tanks and rapid filling or emptying of them to balance the cargo mass being lifted off or placed on the floating vessel while the lift or lower is taking place.3. While a SWATH hull design has much less roll, pitch or heave than a more traditional hull designs, these motions are not zero, and small roll, pitch or heave motions can cause problems.

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