News | Mar 5, 2019

Navy builds towed raft for mine-hunting sub drones

Design is available for manufacturing and sales in commercial markets through a patent license agreement

Mariners aboard thee USS Ponce lower an 11-meter rigid hull inflatable boat to conduct tests on two M18 Mod 2 Kingfish Unmanned Underwater Vehicles.

Blake Midnight/Navy

SAN DIEGO — Three U.S. Navy engineers have built a specialized trailer that can launch mine-hunting drones at the push of a button.

Ralph Hooper, William Chambers, and Jeffrey Gilchrist, inventors of the “Open Water Transport System” at the Naval Information Warfare Center-Pacific were awarded U.S. Patent 10,220,916 on Tuesday.

Illustration of the Open Water Transport System protected by U.S. Patent 10,220,916.

The towed raft measures 8-by-21 feet and can carry two 1,000-pound unmanned underwater vehicles/remotely operated vehicles (UUV/ROV) suspended from a superstructure connecting its two inflatable sponsons.

Triggering the ring clamps in the carriage allows Navy underwater explosive ordinance disposal teams to deploy their counter-mine drones, like the 600-pound Mk 18 Mod 2 Kingfish, for search-classify-map missions.

But when it’s not in use the 750-pound raft can be deflated and collapsed and compacted for storage, or palletized for transportation, which isn’t true for the 33-foot rigid hull inflatable boats currently used to manually launch underwater drones over the gunnels, one at a time, using a winch/crane.

News Article Image of Navy builds towed raft for mine-hunting sub drones

Sailors assigned to Mobile Diving and Salvage Unit (MDSU) 2, unmanned systems platoon, deploy a Mark 18 Mod 2 Unmanned Underwater Vehicle from a 33-foot rigid inflatable craft.

Charles Oki/Navy

The Navy included the Open Water Transport System for its underwater EOD program in the Department of Defense’s 2019 budget request. The funding was identified by congressional appropriators as “early to need” and $5.8 million was cut.

Because it’s inventors work for the Navy, the design, and hundreds of other technologies, is available for license to qualified businesses and entrepreneurs.

By securing a patent license agreement from the Navy, businesses can obtain the rights to make, use, and sell the towed raft to domestic and international customers, for military or non-military applications.

“Telecommunications companies use UUVs/ROVs to search for cables. As yet another example, the oil and gas industry uses UUVs/ROVs for visual inspection, cleaning, and adjusting valves and chokes,” according to the patent.

Licensing inquiries can be directed to Joan Wu-Singel, certified licensing professional and senior technology manager at TechLink, by email at or by phone at 406-994-7705.