U.S. Navy Trials Robotic Towed Connector to Refuel USV

The T38 unmanned surface vessel, left, approaches a towable capture and connection device, center, towed by USNS Vindicator (TSV-5), right, during an Aug. 11 refueling demonstration off Joint Expeditionary Base Little Creek-Fort Story, Va. The U.S. Navy trialled a robotic towed connector to repeatedly capture, refuel and release an unmanned surface vessel (USV) last month as the sea service seeks to enable persistent unmanned operations at sea, according to a Tuesday news release.

The trial, which occurred Aug. 11, involved an underway refueling demonstration designed for USVs carried out by Naval Air Warfare Center Weapons Division (NAWCD) Blue Water Instrumentation (BWI) and BWI’s Future Capabilities Office fleet management team and industry partners Maritime Tactical Systems Inc (MARTAC) and Sealartec.

The trial took place in the waters off Joint Expeditionary Base Little Creek-Fort Story, Va., and was sponsored by U.S. Fleet Forces Command, Naval Surface Warfare Center Dahlgren Division and Naval Surface Warfare Center Carderock Division while the Littoral Combat Ship Mission Modules Program Office (PMS 420) and the Navy’s Portfolio Acquisition Executive for Robotics and Autonomous Systems also provided contracting support that enabled BWI to partner with MARTAC and Sealartec and to run the demonstration.

The demonstration involved using the T38, a Navy-owned remotely controlled USV built by MARTAC and Sealartec’s towable capture and connection device, a robotic refuelling system with the Navy-industry team having moved from concept to real-world testing in seven months. The TCCD was towed by training support vessel USNS Vindicator (TSV-5) during the demonstration.

Sealartec’s Autonomous Replenishment At Sea (A-RAS) system is designed to fit 3- to 24-meter USVs while towed from a ship and is operational to Sea State 6 with a fuel transfer speed of 757 litres in 15 minutes, according to the company’s webpage.

The T38 USV, which is part of MARTAC’s Devil Ray USV family, is a 12.2 meter USV capable of burst speeds of 50 knots and a payload of 4000lbs. MARTAC states that the T38 is capable of carrying out intelligence, surveillance and reconnaissance , surface strike, counter-unmanned aerial systems, anti-submarine Warfare (ASW) Recon, Mine Countermeasures, electronic warfare, logistics and mothership/swarm coordinator missions.

The T38 is also capable of launching and recovering T12 and T18 USVs from the Devil Ray family using Sealartec’s Autonomous Launch & Recovery Systems.

In May, MARTAC announced that the T38 had completed a record-setting eight-day, completely autonomous mission off the coast of California.

A refueling probe on the T38 unmanned surface vessel, left, prepares to mate with a towable capture and connection device, right, during an Aug. 11 refueling demonstration off Joint Expeditionary Base Little Creek-Fort Story, Va. The contracting partnership helped BWI address its operational challenge of keeping USVs and their sensors on station longer during testing of advanced long-range capabilities without increasing reliance on crewed support ships.

“At NAWCWD, our immediate focus is supporting hypersonic and precision long-range fires testing, where flight profiles can extend thousands of miles beyond fixed-range boundaries and require data-collection assets to be distributed across a vast area,” said Spencer Holloway, director of BWI’s Future Capabilities Office, in the release. “But the underlying challenge applies more broadly – every time an unmanned vessel must return to port for fuel, we lose persistence, reduce coverage and redundancy, and interrupt the mission.”

According to Holloway, during the demonstration, the team ran dozens of full-cycle capture, refuel and release exercises at sea, as well as conducted pierside demonstrations with Vindicator, which transferred a total of 400 gallons of fuel to the T38 during the event.

Amitai Peleg, CEO of Sealartec, stated that in total, the refueling system completed approximately 100 connection cycles over the course of a few days leading up to and including the event. The Sealartec team gained insights that will help refine the design process of the TCCD and gained lessons about broader operational processes involving the launch, refueling and recovery of USVs, Peleg said.

“Another major takeaway involved our roadmap for transitioning from a remotely operated refuelling process to a fully autonomous architecture,” Peleg said. “The USV will approach the refuelling device, communicate via automated protocols, and guide itself into position using maneuvering algorithms—virtually eliminating human dependency from the loop.”

Ronald Raymer, branch head for capability, innovation, science and technology integration at U.S. Fleet Forces Command, also took part in the refueling demonstration, according to the release and said unmanned refuelling can strengthen fleet readiness by enabling greater use of USVs.

“This will allow us to have greater reliance on unmanned vessels instead of manned, and we can push the USV into higher threat areas without risking manned vessels and personnel. It will also allow us to distribute greater capability into an area without having to invest in large expensive manned vessels and the refuelling supports that,” Raymer said.

According to the release, BWI’s next milestone is an end-to-end autonomous refueling demonstration that will test vessel rendezvous and approach, capture, fuel transfer, disconnection and return to mission as a single evolution. The immediate work consists of two parts – reducing command-and-control latency to improve precise maneuvering during operator-assisted testing and integrating next-generation local positioning systems to aid in autonomous refuelling.