Naval Warfare Center Showcases Unmanned Refueling at Sea

The Navy took a major step toward enabling persistent, unmanned operations last month when the Naval Air Warfare Center Weapons Division led a demonstration off the coast of Virginia using a robotic towed connector to repeatedly capture, refuel and release an unmanned surface vessel at sea.

In seven months, a Navy-industry team moved from concept to real-world testing using the T38, a Navy-owned remotely controlled USV built by industry partners, and a towable capture and connection refueling system. 
 
The contracting partnership also helped the warfare center’s Blue Water Instrumentation program address a broader operational challenge: keeping USVs and their sensors on station longer during critical capabilities testing without increasing reliance on crewed support. 
 
“At [Naval Air Warfare Center Weapons Division], 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 the program’s future capabilities office. “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.” 
 
During the demonstration, the team ran dozens of full-cycle exercises at sea, in addition to pier-side demonstrations. The training support vessel USNS Vindicator towed the refueling system and transferred a total of 400 gallons of fuel to the T38 during the event. 
 
In total, the refueling system completed about 100 connection cycles over the course of a few days leading up to and including the event.

Ronald Raymer, branch head for capability, innovation, science and technology integration at U.S. Fleet Forces Command, also took part in the refueling demonstration. He said unmanned refueling can strengthen fleet readiness. 
 
“This will allow us to have greater reliance on unmanned vessels … and we can push the USV into higher threat areas without risking manned vessels and personnel,” he said. “It will also allow us to distribute greater capability into an area without having to invest in large, expensive manned vessels, and the refueling supports that.” 
 
The event took place in the waters off Joint Expeditionary Base Little Creek-Fort Story, Virginia, and was sponsored by U.S. Fleet Forces Command, Naval Surface Warfare Center Dahlgren Division and Naval Surface Warfare Center Carderock Division. 
 
The milestone also brought together the Blue Water Instrumentation program team, fleet management team and industry partners. Together, they executed an underway refueling demonstration designed for USVs. 
 
The Littoral Combat Ship Mission Modules Program Office and the Navy’s Portfolio Acquisition Executive for Robotics and Autonomous Systems also provided contracting support that enabled BWI to partner with industry and to run the demonstration.

Holloway said the short timeline from inception of the refueling system to on-water demonstrations came from the collaboration between government and industry, which allowed the team to respond quickly to changes when needed. 
 
“Working directly with our industry partners allowed us to bring the platform, control systems, operators and engineers together as one integrated team,” he said. “We could make changes, test them on the water and iterate quickly based on what we observed.” 
 
The demonstration showed the role of government-industry collaboration in moving the refueling system from concept to testing in seven months.

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.