A Navy ship traveling through hostile waters stops just before transiting a small channel. On the starboard side, an object the size of a small car drops into the water, displacing nine tons as it bobs near the surface. The device begins moving slowly, following a predetermined course while sending out sonar signals in every direction. It’s searching for one of the biggest threats to Navy ships in war zones today and the reason it was invented: mines.

This scenario will soon become a commonplace one aboard USS Momsen (DDG 92). The Arleigh Burke class guided missile destroyer is the newest ship in the fleet and the first to be outfitted with the Navy’s most advanced mine hunting technology, the Remote Mine Hunting System (RMS), said STG2(SW) Jacob Vaught, USS Momsen leading enlisted RMS expert.

“This is the Navy’s first surface launched, autonomous vehicle,” said Vaught. “Its primary job is mine hunting from the DDG. That way we can eliminate having to get the mine hunting community involved. It used to take weeks of on station time for them to show up and then for a mine unit to sweep a channel. That’s plenty of time that could’ve been used on a mission during war fighting.”

The RMS is actually composed of two separate pieces of equipment. The larger part, known as the “truck”, is shaped like a bulging torpedo and is only the means of transportation for the minesweeper.

It’s about the size of a small car and powered by a diesel engine. The actual minesweeper is a smaller torpedo-looking device that’s tethered to the truck by a cable. The cable can be lowered or pulled in to adjust the depth the minesweeper operates at, said Vaught.

“The RMS has five different types of sonar,” said Vaught. “Some search straight down, to the sides and out in front. While its sonar is searching for mines, the truck can lower the RMS to different depths so we can fully explore an area of the ocean.”

Momsen is currently outfitted with a replica the same size and weight of the RMS. The real mine hunter was on board the ship earlier in the year for operational testing. It’s since been returned to the manufacturer’s lab in West Palm Beach for some fine tuning using the data gathered during the machine’s test run. The 30 million dollar machine will be delivered to Momsen in Everett on a flatbed truck soon after the final tests are completed in the beginning of the new year.

When a Navy ship approaches a canal it stops and waits for a minesweeping detachment to arrive and sweep the waterway ensuring the absence of mines. This is a long and tedious process that takes precious time away from the mission, said Vaught. 

“The RMS is designed so we can launch it on ship and it can go ahead and search for mines for us,” explained Vaught. “If it finds absolutely zero mines then we’ll go ahead and transit the canal and we just saved the Navy days and days.

“On top of that, it also saves personnel and equipment. If you run a ship into a mine obviously you’re looking at millions of dollars of damage as well as personnel casualties. Here, even if we lose the unit, which is unlikely, it’s still a lot better than what could happen.”

The RMS can be driven by a remote control from the weather deck of the ship or programmed to run a predetermined course while sweeping for mines that Vaught said are a major hazard to Navy ships.

“Mines are very common,” said Vaught, “especially in the Middle East. A lot of those countries have very great mining capabilities. We actually have detachments over there and that’s their primary mission, sweeping for mines.”

The RMS may soon put those detachments out of a job, when it’s released for wide scale Navy use. But first, USS Momsen will be testing the capabilities of the device for further improvements in the months to come as the ship works up in preparation for its first deployment. Vaught said the developers will run more tests and once they’re comfortable with the program, it’ll be distributed throughout the Navy. Currently, Momsen is the only ship with this unique equipment aboard but others have been built to accommodate the large size of the RMS.