The Navy's Littoral Combat Ship recently searched for submarines and sailed through a dummy mine-field off the coast of San Diego, California, to assess whether the vessel’s anti-submarine and mine-countermeasure technologies could find enemy submarines and successfully detect and destroy underwater mines, service officials said.
The anti-mine developmental and operational tests this past summer took place on board the USS Independence, or LCS 2. The tests involved many aspects of the LCS’ Mine-Countermeasures mission package, a collection of integrated mine-detecting technologies engineered to swap on and off the platform.
“The real purpose of the test was to stress the operational tempo. This is the first time we’ve really done end to end missions on the ship,” Capt. Casey Moton, LCS mission modules program manager, said.
Using a suite of counter-mine technologies, the ship traveled twice through the mock-mine field, successfully detecting the mines in each instance. The test was the first time all three elements of the MCM package were integrated on-board the ship, Moton explained.
The elements consist of a Remote Mine-hunting System below the surface and an Airborne Laser Mine Detection System, or ALMDS, above the water to locate the mines alongside an Airborne Mine Neutralization System, or AMNS, designed to destroy the mines once they are found, he added.
“We wanted to be sure the crew could handle a high-tempo. The crew did extremely well operating through the different stages – search, detect, destroy,” Moton said.
The RMS is comprised of an AQS-20 underwater sonar mine detection system which launches from an autonomous semi-submersible called the Remote Multi-Mission Vehicle, or RMMV. The RMMV, which has both line-of-sight and over-the-horizon capability, is launched from the back of the LCS, Navy officials said.
As many as two RMMVs can operate from the LCS at one time. The RMS works in tandem with the ALMDS, an airborne laser designed to scan the surface and shallow water for mines. Data from both the RMS and ALMDS are assessed at a command center on-board the ship, he said.
“They will basically piece all that together to get a complete picture of where all the mines are. Air assets and the RMS are looking at two different things. The air assets are looking for mines near the surface and the RMS is looking for mines deeper in the water,” Moton explained.
The AMNS involves the use of an MH-60 helicopter which drops a vehicle into the water carrying neutralizer to blow up a mine that has previously been found.
The Navy is now in the process of further analyzing the results of the tests.
“I have to crunch all the data now and see what needs to be worked,” he added.
The MCM package is slated to be operational on board the USS Independence by next summer, Moton said.
Upon initial examination, anti-submarine and counter-mine warfare might seem to call upon the same detection technologies and methods. Moton explained, however, that while there are some similarities, detecting submarines is actually much different that finding mines.
“Mines are harder to find. They don’t radiate any noise and the ranges are shorter. The sonars that are going against submarines have to be much longer range. A submarine is putting out its own noise signature,” Moton explained.
The Navy also recently finished testing of its Anti-Submarine Warfare mission package in September off the coast of San Diego, Calif., on board the USS Freedom, Moton said.
The ASW mission package, slated to be operational by 2016, is earlier in its development than the other two LCS mission packages, the Surface Warfare and Mine-Countermeasures mission packages.
The technologies for the ASW package include use of an active sonar called Variable Depth Sonar deployed off the back of the ship and a passive detection system called a Multi-Function Towed Array, or MFTA.
“We were towing an active and passive detection sonar. This was the first time where we had done a test on LCS where we had towed both of those systems,” Moton said.
An active sonar pro-actively sends out a “ping” or acoustic signal and then analyzes the return to determine the shape, distance and dimension of a given threat; passive sonar is merely listening or receiving pings.
The tests, which included detecting actual submarines, involved mechanical assessments at different speeds to make sure the two systems did not cross, Moton said.
The ASW package also uses MH-60 helicopters to detect and destroy submarines with sonobuoys and lightweight torpedos.
Light Weight Tow torpedo countermeasures, vertical-take-off-and-landing unmanned aerial vehicles and handling gear for the equipment are also parts of the ASW mission package, Navy officials said.
Moton said the Navy is exploring options for acquiring lighter weight handling gear for the ASW package on-board the LCS.