Closed Loop Variable Buoyancy Lifting System for In-Pond Nuclear Retrievals

The in-pond harsh environment closed loop variable buoyancy lifting device relies on the Archimedes principle. Archimedes principle states that a body partially or completely immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the body. By changing the volume of displaced fluid, the device creates a variable lifting force. The novel application is to use a closed loop in which the inflation air is stored under pressure in a receiver. This compressed air inflates the variable displacement to provide lift. To submerge the air is transferred back into the receiver via a compressor and a series of control valves. The small observation class ROV systems currently being operated on the Sellafield site will be able to manoeuvre the suspended load. This can be most clearly demonstrated how historically during the era of canal transportation a horse could easily pull a fully laden 100 ton barge along a canal.