The New Hunter/Gatherers
U.S. Navy's Unmanned Mine Reconnaissance System Will Provide Organic Mine Countermeasures Capability The concept that a naval task force operating in littoral waters can detect underwater mines using remotely controlled unmanned vehicles is on the verge of being realized.
In Syracuse, N.Y., where Lockheed Martin Naval Electronics & Surveillance Systems (NE&SS) division has been developing just such a mine reconnaissance system for the USN, confidence is high that requirements have been met or exceeded.
In Pascagoula, Miss., Ingalls Shipbuilding is constructing USS Pinckney, the first of 11 Arleigh-Burke class guided missile destroyers (DDGs) whose mission will include this mine countermeasures (MCM) capability. By late 2003, the new ship will take delivery of a mine reconnaissance system that will change the way the USN thinks about and conducts what it calls "organic" or "assigned" (i.e. on-board) mine warfare. The system to be carried by each Flight IIA DDG is designated ANAVLD-1 (V) 1. Its principal component is a 23-ft. (7m) semi-submersible, semi-autonomous Remote Minehunting Vehicle (RMV) that tows an advanced variable depth sensor (VDS) whose purpose is to detect, classify, localize and identify moored and bottom mines. The RMV can operate over the horizon from its host ship, sending back mine contact data and obstacle avoidance video imagery via radio link. But WLD-1 is not an isolated phenomenon. It is one of seven organic MCM (OMCM) programs currently under development for the USN. By 2005, these permanently assigned OMCM capabilities will begin extending the combat systems reach of carrier battle groups — and later, potentially, amphibious ready groups. These systems will integrate with the sensors and weapons of ships, helicopters and submarines to enable minefield reconnaissance, minehunting, minesweeping and, if necessary, clearance of the mine threat to enable a limited breakthrough ability. The effect of the organic MCM approach is to mainstream mine warfare in the U.S. Navy from a domain for specialists to a basic skill for all naval warfighters. The Case for Organic On the morning of February 18, 1991, in the northern Persian Gulf, the amphibious assault ship USS Tripoli struck a Pattern 1908 contact mine. The explosion ripped a 20 x 30-ft. hole in the ship's hull on her starboard bow and injured four sailors.
Hours later, the USS Princeton, a guide missile cruiser, detonated an Italian-made MRP acoustic mine lying on the seabed. The gas bubble from the explosion spread underneath the ship's keel transferring large volumes of energy into the structure. While not holed, 80 percent of the structural strength of the ship was compromised. Since the beginning of the Cold War, at least 12 other Navy ships also have been casualties of mines, most during the Korean conflict. The worst mine incident occurred in 1988 during the Gulf Tanker War when the frigate Samuel B. Roberts nearly sank after striking an Iranian SADAF-02 contact mine. Although the mine cost just $ 1,500, the explosion caused nearly $96 million in damages.
Since 1950, the Navy has spent hundreds of millions of dollars to repair ship damage caused by mines each costing only a few thousand dollars. Furthermore, most of the affected ships were out of action for months. Countering asymmetric warfare of this kind would require transformational thinking, strategies and assets.
Already by 1991, changes in world geopolitics were shifting the focus of operations of the Navy forwarddeployed forces from the open ocean to the littorals where mines are prevalent. Littoral waters, by definition, range from the shoreline out to water depths of 600 ft. At issue is the need by carrier and amphibious groups to dominate the littoral space, whether to project power or protect maritime shipping. Unrestricted access to, and maneuverability within, a littoral region's narrow and constricted geographic area are crucial if Navy and allied forces are to prevail. Mines therefore cannot become showstoppers. In addition to executing other missions, ships captains and fleet commanders need to gain quickly the knowledge of the mine threat without having to wait for the arrival of dedicated MCM ships.
From this awareness evolved not only the need for improved MCM forces in the Navy as a whole, but also the more novel solution of battle group ships deploying their own MCM assets. For while forward-deployment of a limited number of dedicated minehunting and minesweeping ships in the Western Pacific and Arabian Gulf reduces the time to respond, the thinking is that any delay is unacceptable for many likely contingencies. The new thinking around organic mine countermeasures was spelled out for the first time in 1995 when the Chief of Naval Operations drew up a concept of operations for organic offboard mine reconnaissance. It coincided with the ever-increasing threat to maritime and naval shipping from mines. The fourth edition (2001) of the U.S. Naval Mine Warfare Plan notes that the "number of countries with mines, mining assets, mine manufacturing capabilities, and the intention to export mines has grown dramatically in the past decade. More than 50 countries currently possess mines and mining capabilities, a 40 percent increase since 1986. Of these, at least 30 countries have demonstrated a mine production capability, and 20 have attempted to export these weapons." Evolution of A Remote Minehunter The evolution of a Remote Minehunting System (RMS) prior to WLD-1 dates back to the early 1990s when the USN began exploring options for mine reconnaissance from surface combatants.
A vehicle initially developed for hydrographic survey in the 1980s by Rockwell International was used by the Naval Surface Warfare Center to prove initial hydrodynamics, telemetry and the concept of towing a VDS behind a remotely operated vehicle. By 1994, the Navy had developed the first RMS prototype, which demonstrated mine reconnaissance using a VDS winch and pylon welded to the RMV's belly. Though launch and recovery was from shore, command and control was demonstrated from a military van aboard a Spruance class destroyer.
In 1996, the same prototype system vehicle was launched and recovered from another destroyer using a modified gravity davit. Later, in January 1997, during exercises in the Arabian Gulf, the system successfully detected, classified and localized training mines from the destroyer USS Cushing. Extensive at-sea Builder's Trails following in late 1998 showed the RMV could travel with full stability at speeds greater than 10 knots. Stability was a key USN requirement.
A smooth riding RMV and VDS under water is crucial to eliminate the equivalent of camera shake, which otherwise would return fuzzy sensor imagery. In 1999, Lockheed Martin was awarded the WLD-1 design and development (Phase I) contract. Critical Item Tests begun in the summer of 2000 validated higher speeds, shipboard launch and recovery in varying sea states, and important RMV design characteristics, including control surfaces, stability/controllability algorithms, propulsor blade attachments and radiated noise measurements. Shore based RMV control and operations also were validated. A final series of tests in the winter of 2001- 02 showed the RMV has the speed and endurance to perform with the VDS in both hull mount and towed modes, and can deploy and retrieve the VDS while underway. Company officials say these tests cumulatively paved the way for a successful Critical Design Review in December 2001.
Concept of Operations When a WLD-1 equipped destroyer enters a littoral zone where sea mines are suspected, mission planners will divide an area to be searched into sectors, and assign 'waypoints' to define the search track. The search area could be within line-of-site of the host ship or over the horizon. Waypoints (as determined by GPS coordinates) are programmed into the RMV before launch using the Mine Warfare Environment Decision Aids Library (MEDAL) system. Once a waypoint is reached, the RMV autonomously initiates pre-programmed commands, such as speed and course changes or VDS deployment and retrieval.
The 13,000-lb RMV is launched via an overboarding davit that extends just beyond the ship's hull. After the mast is raised and communications established, the davit lowers the RMV into the water. A sailor on the host ship uses a remote operator pack strapped to his waist to pilot the RMV far enough away from the ship's hull until the sonar operator can take control. With its powerful Cummins diesel marine engine, the RMV transits just beneath the surface at sustained speeds in excess of 16 knots with only a few feet of mast extending above the water line. The RMV may conduct mine reconnaissance with its VDS hull mounted in shallow water, or automatically deploy the VDS at a programmed waypoint. The sonar search is conducted at speeds up to 12 knots.
A common sensor with the Airborne MCM community, Raytheon's AQS-20 VDS employs four different sonars (ahead-look, volume search, side-look and gap filler) to detect, localize and classify bottom, closetethered and moored mines. Contacts classified by sonar-processing algorithms as 'mine-like' can be positively identified using the VDS' high-resolution elec- tro-optical laser imager.
Sensor data and obstacle avoidance video imagery returned by the RMV via line-of-sight or over the horizon data links are monitored by a sonar operator using the host ship's AN/UYQ-70 sonar console, which links with ship's AN/SQQ-89 undersea warfare system. Image data is also stored in the RMV's on-board recorder for post mission analysis. Until recovered (approximately 24 hours or more later), or when commanded otherwise, the RMV will independently perform mine reconnaissance across the designated search area, allowing the host ship to conduct other operations. If necessary, the operator can use the console to manually adjust the RMV's course and speed while it searches for mines.
If an emergent threat to the host ship (a submarine for instance) requires use of the sonar consoles while the RMV is searching for mines, the ship's CO can command the RMV to continue autonomously, direct it to a new rendezvous point, or power down the system to "station keeping/sleep mode" until reactivated. Multi Mission Capabilities While the USN may be alone in its requirement for an organic approach to littoral mine reconnaissance, the applications for WLD-1 as a platform for multimission tasking are extensive and varied.
First to mind is its supplemental use as an intelligence collection device close in shore where it is more difficult to deploy a submarine. Lockheed Martin is currently evaluating the system's potential for Naval Coastal Warfare, Force Protection and Anti-Terrorism applications. Such shallow water missions would complement maritime coastal defense, as well as protection of ports, harbors and anchorages. Using the RMV with its VDS, regional defense forces could conduct active anti-submarine warfare (ASW) operations. Seabed mapping, Q-route surveying and shallow water battlespace profiling are other obvious applications. As a surface surveillance data collector close to shore, the RMV mast could be outfitted with high-resolution optical sensors, such as low-level light cameras, infrared sensors, and surface search radar.
The RMV could become a low-risk platform to collect communications, signal and electronic intelligence. It could fill in any coverage gaps by other collectors, such as submarines or satellites. The RMV could also serve as a communications relay between surface craft, other UVs and command centers.
Future variants of WLD-1 may feature a lighter, smaller RMV with automated launch and recovery, increased sensor area coverage rate, and enhanced obstacle avoidance features. In many cases, the system would be launched from a pier or ship of opportunity, with data fed to a portable command and control van on shore.
Fleet Introduction and Acceptance Fleet introduction of WLD-1(V)1 will occur after new tactical doctrine has been approved, and the system tested at sea by a DDG91 ship's company in 2004-5. Lessons learned from those tests will determine the best ways to incorporate WLD-1 operations and procedures for follow-on ships without adversely impacting their primary mission.
Arguably the biggest near-term challenge is to overcome ships captains' and fleet commanders' concern about having the system on board, particularly given the traditional reliance on dedicated minehunters to perform MCM.
Complementary to that goal is the need to train personnel to become expert in the technical, tactical and operational role of organic mine warfare.
On paper at least, a good indication of the evolving mindset toward mine countermeasures of the future is how the USN uses terminology. Already the term "organic" is giving way to the term "assigned" - the latter term implying greater permanency. So too the term "dedicated" as applied to fixed mine warfare forces, such as minehunting ships, is being replaced by the term "supporting" - as in supporting carrier and amphibious groups that will find and neutralize mines with their own "assigned" MCM assets.
Ultimately, operational success, not terminology, will convince COs of WLD-l's viability in battle conditions. But just as unmanned airborne vehicles have become indispensable battle tools, so too will unmanned semi-submersible vehicles like the RMV. The success of unmanned aerial vehicles in Afghanistan, and calls by President George W. Bush and U.S. Secretary of Defense Donald H. Rumsfeld for more "transforming technologies," should ensure WLD-1 gets top-level support.
The preceding article was first published in the April 2002 issue of World Defence Systems.