The U.S. Navy has improved the reliability of its remote mine-hunting system for the Littoral Combat Ship through a series of tests off the coast of Palm Beach, Fla., service officials said.
The so-called Remote Minehunting System, or RMS, consists of a semi-submersible with the AN/AQS-20A variable depth sonar and is designed to locate mines in shallow and deep water, officials said.
“Getting through this was really important to the whole progression of the program and efforts to get the system fielded to the fleet,” Steve Lose, who manages the program for the Navy, said in an interview. “The big plus is what RMS is going to bring to the mission and keep sailors and ships out of the mine field.”
The reliability testing decreased the average time the system failed between missions, thus increasing the effectiveness of the technology, Lose said.
The Navy adopted a test-fix-test approach wherein the system was put through a series of operationally-relevant scenarios designed to push the envelope of its electronic, hydraulic and navigational components, Lose said.
“The end product was an engineering change proposal – a design change whereby a problem is corrected,” he said. “We looked at previously identified failure modes, tested, did an analysis, then fixed the design for reliability.”
The evaluations led to improvements in hydraulic systems that help the semi-submersible turn, remain stable and change depth,” Lose said. The device is propelled by a standard diesel engine, however, hydraulic systems are needed for control, Lose said.
“We improved the overall capacity of the hydraulic system,” he said. “The vehicle is heavily dependent upon hydraulics.”
The testing, conducted by the maker of the mine-hunting system, Lockheed Martin Corp., included Navy sailors and engineers, as well as independent technical experts tasked with identifying and correcting problems on the system, Lose said.
Lockheed received a $52.9 million contract in May from the Navy to integrate the system into the LCS mine countermeasures mission package on both Lockheed’s Freedom ship and Austal’s Independence, company officials said.
Overall, the system completed more than 850 hours of testing during 47 missions over a four-month period, assessments which included exercises utilizing the AN/AQS-20A sonar to locate debris and “mock” mines on ocean floor.
“We attempted to operationally simulate how it will operate from the LCS, where you can program missions,” Lose said. Future tests will involve testing the remote mine-hunting system in an actual mine field, he said.
The sonar is lowered to additional depth beneath the surface through use of a long cable tethered to the submersible, Lose said.
The reliability testing also involved simulated conflict scenarios and took place off the shores of a Lockheed Martin facility at Riviera Beach, Fla., according to Steve Froelich, who manages the system for the contractor.
“We got together with some design reviewers and identified the need to design a fix for anything that had caused the system to interrupt the mission,” he said.
Following the daily exercises, data from the simulated mine-hunting scenarios was loaded onto a data recorder that compiled such information as temperature, pressure, revolutions per minute and sonar levels, Froelich added.
The testing also examined the navigational system of the submersible, which uses what’s called a semi-autonomous capability, meaning the vessel can travel along a path or trajectory that is pre-programmed by computers using global positioning system waypoint technology, Froelich said.
The remote mine-hunting system is an key part of the ship’s mine counter-measures mission package, a so-called modular suite of technologies engineered to work together to defend the vessel against explosive devices placed in water.
Under its deal with the Navy, Lockheed will ultimately upgrade semi-submersible on as many as 10 ships and integrate communications systems designed to enable sailors to operate two of the submersibles at the same time, Lockheed officials said.