An example underwater vehicle includes a first section detachably coupled to a second section that is positioned forward of the first section, and a hinge detachably coupling the first section to the second section, where the hinge creates a pivot between the first section and the second section. The underwater vehicle includes a lock having a locked position and an unlocked position, where, in the locked position, the lock couples the first section and the second section together, and where, in the unlocked position, the second section is capable of decoupling from the first section. The underwater vehicle also includes a drag fin associated with the second section that is movable to an extended position away from the second section to create a drag force which causes the second section to pivot about the hinge, away from the first section, when the underwater vehicle is traveling through a fluid medium.

A thrust reversal emergency jettison device for an underwater vehicle includes a thrust reversal mechanism. The thrust reversal mechanism includes a casing and a gas reaction compartment provided in the casing; the gas reaction compartment communicates with a gas passage in a shell of the casing through a gas pipe; and a bottom end cover is provided at a bottom of the gas reaction compartment, and the bottom end cover is hermetically connected with the gas reaction compartment through a cylinder mechanism, and falls off automatically when a gas pressure in the gas reaction compartment increases. Compared with the prior art, the present invention can provide a reverse thrust for an underwater vehicle in an emergency, help the underwater vehicle to ascend, and improve safety.

A thrust reversal emergency jettison device for an underwater vehicle includes a thrust reversal mechanism. The thrust reversal mechanism includes a casing and a gas reaction compartment provided in the casing; the gas reaction compartment communicates with a gas passage in a shell of the casing through a gas pipe; and a bottom end cover is provided at a bottom of the gas reaction compartment, and the bottom end cover is hermetically connected with the gas reaction compartment through a cylinder mechanism, and falls off automatically when a gas pressure in the gas reaction compartment increases. Compared with the prior art, the present invention can provide a reverse thrust for an underwater vehicle in an emergency, help the underwater vehicle to ascend, and improve safety.

Systems and methods for buoyancy compensation are provided. Both active and passive buoyancy compensation can be provided using a compressible mixture made of a liquid along with a hydrophopic material such as a powder, electrospun fiber, or foam. The compressible fluid compresses as pressure is applied or expands as pressure is released thereby substantially maintaining an overall neutral buoyancy for a vessel. This allows the vessel to ascend and descend to water depths with minimal active buoyancy change. As a result, the energy usage and the reliance on higher pressure air and oils can be minimized.

Systems and methods for buoyancy compensation are provided. Both active and passive buoyancy compensation can be provided using a compressible mixture made of a liquid along with a hydrophopic material such as a powder, electrospun fiber, or foam. The compressible fluid compresses as pressure is applied or expands as pressure is released thereby substantially maintaining an overall neutral buoyancy for a vessel. This allows the vessel to ascend and descend to water depths with minimal active buoyancy change. As a result, the energy usage and the reliance on higher pressure air and oils can be minimized.

An example underwater vehicle includes a first section detachably coupled to a second section that is positioned forward of the first section, and a hinge detachably coupling the first section to the second section, where the hinge creates a pivot between the first section and the second section. The underwater vehicle includes a lock having a locked position and an unlocked position, where, in the locked position, the lock couples the first section and the second section together, and where, in the unlocked position, the second section is capable of decoupling from the first section. The underwater vehicle also includes a drag fin associated with the second section that is movable to an extended position away from the second section to create a drag force which causes the second section to pivot about the hinge, away from the first section, when the underwater vehicle is traveling through a fluid medium.

An example underwater vehicle includes a first section detachably coupled to a second section that is positioned forward of the first section, and a hinge detachably coupling the first section to the second section, where the hinge creates a pivot between the first section and the second section. The underwater vehicle includes a lock having a locked position and an unlocked position, where, in the locked position, the lock couples the first section and the second section together, and where, in the unlocked position, the second section is capable of decoupling from the first section. The underwater vehicle also includes a drag fin associated with the second section that is movable to an extended position away from the second section to create a drag force which causes the second section to pivot about the hinge, away from the first section, when the underwater vehicle is traveling through a fluid medium.

The present invention provides a device useful for transporting and/or handling equipment in an underwater environment for performing work, the device comprising at least the following components: a floating hydraulic unit (1) comprising a first enclosure (1a), preferably with a cylindrical wall, containing an electrical pump unit (6), a battery (8) suitable for electrically powering the pump unit, and a fluid tank (7), preferably containing oil, said first enclosure (1a) being suitable for being made submersible by first ballast (16); at least one hydraulic tool (3) connected or suitable for being connected to at least one hydraulic coupling (11, 12) of said hydraulic unit via at least one flexible hose (30); at least one independent float (4), preferably having a cylindrical wall, connected or suitable for being connected to said hydraulic tool (3) via a sling (5) of adjustable length, said float (4) being suitable for being made submersible by second ballast (43); and a wired remote control (2) for switching on or stopping the pump unit (6), said wired remote control comprising a handle (22) fitted with an electrical contactor (2a) at a first end of an electric wire (20), the second end of the electric wire (20) being connected or suitable for being connected at least to said pump unit (6).

A variable buoyance engine includes a pressure vessel, a reservoir, an external bladder, a non-compressible fluid inside the reservoir and the external bladder, and a drive system. The drive system includes a shape memory alloy actuator, a piston attached to the actuator, a power source connected to the actuator, and a controller configured to control application of power to the actuator. The power source is configured to cause the actuator to change temperature and deform when power is applied to the actuator thereby moving the piston from a first position to a second position. The reservoir and external bladder are configured to retain, without leakage, the non-compressible working fluid. The external bladder is configured to receive the non-compressible working fluid from the reservoir when the actuator moves the piston from a first position to a second position to create a second, positive buoyancy state and to expel the non-compressible working fluid from the external bladder to the reservoir when the actuator moves the piston from the second position to the first position to create a first, negative buoyancy state.

A variable buoyance engine includes a pressure vessel, a reservoir, an external bladder, a non-compressible fluid inside the reservoir and the external bladder, and a drive system. The drive system includes a shape memory alloy actuator, a piston attached to the actuator, a power source connected to the actuator, and a controller configured to control application of power to the actuator. The power source is configured to cause the actuator to change temperature and deform when power is applied to the actuator thereby moving the piston from a first position to a second position. The reservoir and external bladder are configured to retain, without leakage, the non-compressible working fluid. The external bladder is configured to receive the non-compressible working fluid from the reservoir when the actuator moves the piston from a first position to a second position to create a second, positive buoyancy state and to expel the non-compressible working fluid from the external bladder to the reservoir when the actuator moves the piston from the second position to the first position to create a first, negative buoyancy state.