Abstract

A floatation device (100) is provided comprising a buoyancy chamber (110); a cryogen reservoir (210); and a heating pipe (310) providing switchable fluid communication between the cryogen reservoir (210) and the buoyancy chamber (110). A method of raising an item from the seabed is also provided. The method comprising the steps of lowering a floatation device (100) to the seabed; attaching the floatation device (100) to the item to be raised; creating a supercritical fluid within a portion of the floatation device (100); and allowing the floatation device (100) and the item to rise to the surface using the buoyancy of the supercritical fluid to raise the item to the surface.

IPC Classes  ?

• B63C 7/10 - Salvaging of disabled, stranded, or sunken vesselsSalvaging of vessel parts or furnishings, e.g. of safesSalvaging of other underwater objects in which lifting action is generated in, or adjacent to, vessels or objects using inflatable floats external to vessels or objects

Abstract

A floatation device is disclosed that comprises a container 10 containing a liquefied gas, a gas chamber (60, FIG. 2) and a remotely operable device 29. The remotely operable device is switchable between a closed state in which fluid communication between the container and the gas chamber is prevented, and an open state in which fluid communication between the container and the gas chamber is enabled and vaporization of the liquefied gas charges the gas chamber with gas. The liquefied gas may be liquid nitrogen and the container may be heat insulated with an insulating vacuum cavity. A buoyancy unit (40, FIG. 2) which comprises a rigid enclosure (42, FIG. 2) defining an interior volume and a flexible diaphragm (55, FIG. 2) that partitions the interior volume into first and second chambers is also disclosed.

IPC Classes  ?

• B63B 22/18 - Buoys having means to control attitude or position, e.g. reaction surfaces or tether