U.S. Navy tests camera system that spots sailors overboard

U.S. Navy engineers in California have tested a prototype camera system designed to spot a sailor falling overboard and alert the ship’s bridge automatically, throwing a 35-pound rescue dummy off the side of a decommissioned destroyer to see whether the cameras would catch it.

The test took place on Aug. 14 aboard the Self Defense Test Ship, which was docked at Port Hueneme, California, where a team from Naval Surface Warfare Center, Port Hueneme Division temporarily mounted the Man Overboard Detection System on the starboard side of the bow. Branch manager Eric King said the system worked flawlessly, although the bridge alarm it is meant to trigger was not part of the test.

King said he believes the system “bridges a gap by providing immediate, automated man-overboard alerts, enabling rapid-response search and rescue operations when seconds count.”

The prototype uses thermal cameras, which detect body heat and can work in darkness, mounted on metal pedestals that extend horizontally from the deck out over the water. For the test, the team installed two cameras in each of two pedestals placed about 61 meters (200 feet) apart and held them to the deck with powerful magnets and counterweights, while permanent versions would be welded in place.

“We needed two thermal cameras per pedestal because one of them captures the short-range blind spot view of the ship and the other camera captures the medium- to long-range view of the ship,” said systems engineer David Dozal, who leads the project.

Dozal said the software compares the overlapping views from opposing cameras to confirm that someone has gone over the side, which allows it to sound the bridge alarm in real time and give responders the exact location where the person entered the water. In a full installation, the cameras would ideally cover the entire perimeter of a U.S. Navy destroyer.

To simulate a fall, the team bought a 1.8-meter (6-foot) vinyl water rescue training dummy named OSCAR, after the international signal flag for “man overboard.” Dozal and mechatronics engineer Daniel Lopez dropped the dummy over the side several times on a rope, hauling it back aboard between throws, while computer engineers Jessica Diaz and Nayeli Mateo checked on a laptop inside the ship that the system had recorded each event correctly.

Much of the hardware and software came from the commercial market. The video analytics software was developed by a private company for the cruise ship industry, and the Navy team used part of its research funding to license it, while the same company built the pedestals to a design drawn up in-house at Port Hueneme. The four thermal cameras were bought off the shelf. The Navy did not name the company.

The cruise industry has a regulatory reason to build such tools: the Cruise Vessel Safety and Security Act, passed by Congress in 2010, requires passenger cruise ships to integrate technology that can capture images of passengers or detect those who have fallen overboard, to the extent such technology is available.

The Self Defense Test Ship itself is the former USS Paul F. Foster (DD 964), a Spruance-class destroyer decommissioned in 2003 and now used by the Port Hueneme division as a floating test platform, often operated by remote control, for ship self-defense weapons and sensors.

The project was funded through the Naval Innovative Science and Engineering program, which supports early-stage research at Navy warfare centers, but that money has now run out. King said the team needed the test results to prove the concept and has started talks with potential sponsors, including the possibility of folding the system into a larger program.

Dozal said the next step would ideally be a temporary installation aboard an active destroyer in San Diego, tested both in port and at sea, which would require a longer window, such as a maintenance period, to fit cameras around the whole ship and route cables safely.

“We also need to calculate the complete MOB installation cost to put it entirely around one Navy ship; we need those numbers to show to a funding source,” Dozal said.