Philip Smart | Pacific 2017, Sydney

By the end of October DST Group and Australian company Ron Allum Deep Sea Services will begin testing a long-range unmanned underwater vehicle with no mechanical propulsion.

The Deep Ray ‘glider’ UUV is an undersea flying wing with an internal buoyancy vessel that can be flooded or pumped out to change the vehicle’s displacement, making it sink or rise. The resulting movement of water over the wing’s surface generates forward thrust, removing the need for propeller or waterjet propulsion. It is built partly of Allum’s patented “syntactic” composite foam that holds its shape even at extreme pressures, giving the glider greater depth capability than manned submarines.

The glider may allow missions of up to three months, gliding more than 2,000 nautical miles

DST Group is exploring the Deep Ray’s utility as a long-range “cross country” mobile acoustic surveillance platform generating little or no noise in the water, allowing its sensors to detect quieter targets at longer range. Its ability to travel long distances in a shallow dive means onboard batteries can power sensors rather than propulsion. The glider may allow missions of up to three months, gliding more than 2,000 nautical miles (3,700 km).

“It’s very low self noise, so it’s hard to detect,” said Ron Allum. “It’s not on the surface, so no one can see it.”

While the glider’s means of thrust is similar to an airborne glider, its navigation issues are more similar to those of a hot air balloon. Water currents travel at varying speeds and directions at different depths, requiring a 3D approach to mission planning. Deep Ray’s ability to go deep allows it to avoid wind driven surface currents that can significantly affect a glider’s flight to depths of 500 metres.

In July this year NSW-based Ron Allum Deep Sea was awarded a $3.17 million contract to provide the glider vehicle and explore its feasibility, following on from a previous collaboration that saw a small scale prototype ‘Sun Ray’ glider tested as a proof of concept. DST Group is collaborating with university partners to provide a robust autonomous control system for reliable operation in a communications-restricted environment.