A modular subsea fluid storage unit has a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formations. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. A vehicle configured to inspect the tank can include a propeller, a battery, a control unit, an inspection device, and a ranging device. The battery provides power to the propeller, the control unit, the inspection device, and the ranging device. The control unit generates a map of the tank. The control unit determines a first position of the vehicle on the map of the tank. The propeller moves the vehicle through the flammable fluid in the tank. The inspection device determines a quality metric of a portion of the tank. The control unit causes the propeller to move the vehicle from the first position to a second position within the tank. The control unit determines the quality metric for the portion of the tank at the second position within the tank, and stores the quality metric.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. A vehicle configured to inspect the tank can include a propeller, a battery, a control unit, an inspection device, and a ranging device. The battery provides power to the propeller, the control unit, the inspection device, and the ranging device. The control unit generates a map of the tank. The control unit determines a first position of the vehicle on the map of the tank. The propeller moves the vehicle through the flammable fluid in the tank. The inspection device determines a quality metric of a portion of the tank. The control unit causes the propeller to move the vehicle from the first position to a second position within the tank. The control unit determines the quality metric for the portion of the tank at the second position within the tank, and stores the quality metric.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.

A modular subsea fluid storage unit comprises a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formations. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

A subsea fluid storage system comprising a soft bladder disposed within a pressure balanced reservoir, a rotatable piston, and a piston rotator which rotates and twists the rotatable piston as it travels along a predetermined axis within the pressure balanced reservoir, predictably and repeatabley collapses the soft bladder when the rotating piston cooperatively travels about the piston rotator, twisting the soft bladder as the rotating piston moves along the predetermined axis, collapsing the bladder inward and thereby emptying the bladder of fluid within the bladder. The piston's rotation pulls the soft bladder away from the pressure balanced reservoir's interior, thereby preventing the bladder's binding or pinching the pressure balanced reservoir's interior. In configurations, fluid is allowed to enter the pressure balanced reservoir via a valve until a balance is achieved between an interior and an exterior of the pressure balanced reservoir.

A composite structure of a cargo body and a method of making the same are disclosed. The composite structure includes at least one electrical grid embedded within fiber-reinforced polymer (FRP) layers. The embedded electrical grid includes a plurality of conductive fibers and a plurality of insulating fibers integrated into a polymer matrix of the FRP layers. The embedded electrical grid may be used for power distribution, structural strengthening and stiffness, and/or puncture detection.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.

Systems, methods and apparatuses for inspecting a tank containing a flammable fluid are provided. The system includes a vehicle having a propeller, a latch mechanism, a pressure switch, and an inspection device. The system includes a control unit in communication with the propeller, the latch mechanism, and the inspection device, and electrically connected to the pressure switch. The control unit powers on responsive to the pressure switch detecting an ambient pressure greater than a minimum threshold. The control unit receives, from the latch mechanism, an indication of a state of the latch mechanism. The control unit determines that the cable used to lower the vehicle into the tank containing the flammable fluid is detached from the vehicle. The control unit commands the propeller to move the vehicle through the flammable fluid. The control unit determines a quality metric of a portion of the tank.