Abstract: A new pneumatic load transfer and shock absorbing system is disclosed. The pneumatic system includes a layer of air-bags to perform two basic functions during a floatover installation operation: 1) lifting the platform deck from the support to create additional air gaps at the mating surfaces, and the heave motions of the lifted platform deck may be reduced; 2) performing as a shock absorbing device with variable vertical stiffness easily controlled by the air-bag internal air pressure during the mating operation and the separation operation.

Abstract: A new pneumatic load transfer and shock absorbing system is disclosed. The pneumatic system includes a layer of air-bags to perform two basic functions during a floatover installation operation: 1) lifting the platform deck from the support to create additional air gaps at the mating surfaces, and the heave motions of the lifted platform deck may be reduced; 2) performing as a shock absorbing device with variable vertical stiffness easily controlled by the air-bag internal air pressure during the mating operation and the separation operation.

Abstract: A new jacket installation method utilizes inflatable buoyancy members for shallow water jacket installation. Two types of inflatable buoyancy members are introduced: 1) the first type is designed to produce a large water plane area in order to improve the jacket floating stability when it is afloat; 2) the second type is designed to produce net buoyancy when they are submerged under water, This new installation method is able to use a small size crane vessel, with lifting capacity less than the weight of the jacket to be installed, for a large and heavy shallow water jacket.

Abstract: A new jacket design method is disclosed, especially for deepwater water heavy jacket applications. The method utilizes a special type of air bags, called Ship Launching Air Bags (SLAB), to provide low cost temporary buoyancy used for jacket installation purpose only. A designer only needs to satisfy the jacket stiffness for the resistance of environmental and gravity loads without the consideration of jacket reserve buoyancy. The required jacket reserve buoyancy could be increased with the utilization of temporally attached SLABs during the jacket installation.

Abstract: A new jacket installation method is disclosed, especially for shallow water heavy jacket installation applications. The method utilizes a special type of air bags, called launching air bags, to provide low cost net buoyancy in order to make a shallow water jacket self afloat with a sufficient bottom clearance with seabed. At a floating state a minimum size installation crane vessel could be used to perform all needed jacket installation operations such as lowering, setting-down to seabed, driving foundation piles, grouting and the welding between foundation piles and jacket leg tops. For a shallow water heavy jacket installation, a crane vessel cost usually represents a majority cost of a jacket installation. Therefore, a significant savings could be achieved if a minimum size crane vessel could be used, instead of a large size crane vessel.