Even though Iran has backed away from from its threats to lace the Strait of Hormuz with mines, militaries around the world (the US included) continue to employ the devices in large numbers — as much as 200 times as often as any other kind of maritime weapon. So, to augment the DoD’s ageing fleet of Avenger-class vessels and empower the new fleet of Littoral Combat Ships, Raytheon has developed the helicopter-launched Airborne Mine Neutralization System.
Given how easy it is to install an undersea mine (they can either be moored or simply sit on the seabed) and their destructive capabilities, they’re highly effective naval deterrents capable of holding back full armadas from sensitive coastal areas, waterways, and strategic choke points. Raytheon’s Airborne Mine Neutralization System (AMNS) is designed specifically to counter this threat by finding and destroying the mines before the rest of the carrier strike group floats into them.
The AMNS consists of two major subsystems. The Remote Mine Hunting System which pairs Raytheon’s AQS-20 mine-detection sonar with Lockheed’s autonomous Remote Multi-Mission Vehicle. The RMMV is first launched from from an LCS and sets about scanning the area in question with high frequency sonar. Any present mines generate a ping and are recorded for higher-frequency investigation. As Greg Black, Director of Underseas Systems at Raytheon, explained to Gizmodo, “The higher frequency sonar, has a broadband component to it, so it’s a range of high frequencies. The wavelength of the frequency is smaller, the physical wavelength is smaller with the higher frequency, and it’s therefore able to resolve more details of the object.”
Once the RMMV’s operators are confident they’ve found a mine, the second major subsystem comes into play: the MH-60-launched ASQ-235 Airborne Mine Neutralization System. “this is a helicopter-based system,” Black continued, “that will use information from the AQS-20 mine hunting system to go back out to the location of the mine with the helicopter, re-acquire the mine and ultimately neutralize it.”
The ASQ-235 itself is composed of the Launch and Handling Carrier — a hoist-deployable launch platform that the MH-60 crew lowers in the water and from which the Neutralizer ROV launches. The LHC also provides a communications link back to the operator via a fibre-optic data link that provides sonar and video feeds. Once the operator relocates the mine, he commands the Neutralizer, in this case, Britain’s Archerfish to detonate its shaped charge against the threat, destroying them both.
This two-prong approach to undersea demining may seem convoluted but its certainly better than sending sailors out in wooden-hulled ships to shoot at mines with .50 cal machine guns.[Raytheon 1, 2 – Navy – OSD – Images: US Navy]