In recent years numerous articles have been published about mine warfare (MIW), some in Proceedings, that may give the impression that a dedicated mine warfare force is no longer needed and will soon go the way of the blimp. Meanwhile, the Navy has modified several Arleigh Burke-class destroyers with the AN/WLD-1 remote minehunting system (RMS). The problem is that this gives a false and dangerous impression that the RMS is a total mine countermeasures, or MCM, package. While very capable of executing its minehunting function, the RMS is in no way equipped to complete the entire MCM problem. This is a dangerous mindset and one that needs to be addressed.
To appreciate some of the problems with the current direction the Navy has chosen for mine warfare, a few points need to be understood.
Mine countermeasures involve several phases in the detect-to-engage sequence. The RMS can only accomplish the minehunting portion of that sequence—search, detect, identify—which still leaves the local mine countermeasures commander with a mine to deal with if one is positively identified. In pelagic ocean or large bodies of water, the force commander can choose simply to mark the mine (using either a Dan buoy system or electronic marker) and direct the force around the mine danger area, or MDA. This is usually not an option in most strategic choke points in the world. An MDA is a one-nautical-mile radius around a known mine. Unless the minefield planner was inept, the minefield density will be tight enough to allow any single mine to be removed or destroyed and still maintain MDA coverage. The only real option open to the force commander in a choke point is to remove or destroy enough of the known mines to create a safe transit lane. Unfortunately, the RMS can only provide a part of the MCM mission-mine hunting.
Limitations of the RMS-and Fleet Resources
A selling point of the RMS is its autonomous, over-the-horizon capability. While the remote minehunting vehicle, or RMV, is capable of working autonomously, it will often be counted on to relay near-real-time data to the destroyer via data link. This would allow the sonar data to be analyzed in near real time. Unfortunately, the average size of a mine threat area (MTA) will require the RMS to operate over the horizon. Since data link is line of sight, the vehicle will often be hunting in the autonomous mode. Even with a small minefield, the RMS will very likely be over the horizon at some point during its operations, ending the near-real-time data link. While the RMV will still be collecting data during these periods, that data will have to be downloaded and analyzed after the mission is complete. Post-mission analysis of the data is basically a one-for-one as far as time to accomplish is required. This effectively doubles the time (time to gather and to analyze the data) to get a complete minefield picture to the planning staff.
A typical choke point MTA is several miles long with some type of restriction, for example, land or shoals, on the sides that limit the maneuverability of the destroyer. Even if the MTA is located in the center of the Persian Gulf, as so many were during both Operation Earnest Will and the first Gulf War, the destroyer will often be out of sight of the RMS if it is required to perform any duties other than simply shadowing the vehicle. One of the main premises for using unmanned undersea vehicles for MCM missions is to keep our Sailors out of a minefield. If the destroyer is to maintain the link it will at some point have to enter the MTA.
A major factor in the success of any RMS operation is the intelligence-preparation capability. An October 2007 GAO defense acquisitions report on mine countermeasures capabilities states that:
The Navy has reduced its investments in intelligence preparation capabilities-including the capability to locate and map minefield boundaries-even though improvements in this area could reduce mine countermeasures mission timelines by 30 to 75 percent. These capabilities are especially important for the littoral combat ship, as it must stand clear of suspected minefields. As these capabilities degrade, the distance at which the [DDG] must stand off from a suspected minefield can be expected to increase.
This requirement to "stand clear of suspected minefields" applies to destroyer as well as littoral combat ship platforms.
Operations in a suspected minefield are difficult enough, but if the ship is in port when the channel is mined, another severe limitation of the AN/WLD-1 RMS becomes clear: it cannot deploy the RMV if it is not under way. While in an emergency it may be possible to deploy the vehicle, if the ship is portside-to, it is not designed for that operation. Once the RMV has completed its search of the port, recovery may not be possible with the current system. This would pose a real problem if the data-link system was not operating and the data needed to be directly downloaded from the vehicle.
Given today's shrinking Fleet, each ship is being stretched to the limits of its capabilities, and ships' crews also are overextended. Crew members are often assigned multiple tasks. This situation will be repeated on destroyers equipped with the AN/WLD-1 system. The time spent employing the RMS will be minimal. This means that crew members trained to operate, maintain, and interpret data from the RMS will have little chance to sharpen their very perishable skills. It is difficult to believe the crew could handle MIO, strike, normal air/surface surveillance, and operating the RMS. Even a well-trained and motivated crew can only keep that up for two to three weeks without getting burned out, and burnout leads to tired watchstanders who make mistakes. This is not to mention that there is no mine countermeasures commander helping in this concept, so not only is the crew doing the operations, they also have to do the planning and reporting.
Time and Environment
If you were to boil down mine countermeasures into a single word, that word would be slow. The average schedule of advance (SOA) for an Avenger-class ship conducting mine countermeasure operations is around 1.5 knots. This takes into account the normal speed during minehunting of 3 knots, with the time spent prosecuting mine-like contacts reducing the SOA accordingly. Is this to assume that the RMS was able to meet the required mine warfare timelines easily? In my 14 years of mine warfare experience I don't recall ever completing a mine clearance operation in the allotted time.
A number of things affect the SOA of a minehunting operation (for both dedicated MCM assets and unmanned underwater vehicle systems) such as bottom type, sea state, clutter density, and expected threat. The bottom type (e.g., sand, mud, or rock) does not vary much from year to year. The amount and type of clutter on the bottom, however, changes constantly. An area with even a smooth, sandy bottom will be difficult to clear if it is littered with mine-like objects (anything larger than a trash can). The Naval Oceanographic Office's journal, Oceans ("Using a minehunting sonar for real-time environmental characterization"; 1999, Volume 1), states:
The problem is that the littoral battle space where these operations take place is dynamic in both time and space. Databases do not always exist in these "hot areas," and where they do they may be based on few real observations, necessitating extensive interpolation and/or interpretation.
One advantage of the RMS is that it can conduct bottom mapping of strategic areas to aid in future operations. If a DDG were tasked to conduct RMS operations in vital areas during peacetime, the ability to conduct change-detect operations during a crisis would enable the task force to transit an area without having to clear mines (understanding that there is still some risk due to undetectable mines).
Prior to the Navy's decision to move the surface MCM vessels from various ports around the United States to Ingleside, Texas, one of their missions was to conduct bottom mapping of the port's shipping channel. The exact locations of the detected contacts were passed to Commander, Mine Warfare Command (CMWC) for inclusion in a contact database. This database was used for change detection (the comparison of detected objects with known objects) to reduce the time required to hunt an area if mines were suspected. Following the move to Ingleside this critical mission effectively ended, which drastically increased the time required to conduct minehunting operations in a port.
Any bottom condition information currently collected is done primarily by the National Oceanic and Atmospheric Administration, and the data are forwarded to its database. While these data have value, they were not collected with the MIW mission in mind and are therefore not as complete as the previous CMWC database.
Most MCM operations are limited to a sea state of three (SS3) or less. This is due to the equipment used. As Navy Commander Stephen J. Coughlin pointed out in his June 2008 article in Proceedings, "The hardware associated with handling the RMV performs adequately in calm seas but leaves to chance the loss of the vehicle in anything greater than sea state three." On Avenger-class vessels the deployment of the AN/SLQ-48 Mine Neutralization System vehicle is limited to SS3. MCM helicopters are also limited to lower sea states due to deployment limitations of the hunting and sweeping systems.
Clearance Operations
Knowing where a mine is located without the capability to clear or neutralize it is like knowing where a sniper is and not killing him. The DDG/RMS system is a very good reconnaissance system, but it is not a full MCM package.
How does the expected threat slow down the mine countermeasures problem? The mines don't maneuver like a submarine (some do move, however), and you don't have to out-think them. But they are some of the most difficult weapons to detect and counter.
Back when the mine threat was simply a large black ball with contact horns, the problem was simple. Today's bottom mines, constructed of fiberglass or carbon fiber, make detecting even one the size of a trashcan more difficult. If the mine has had time to scour, or bury, the chance of detection is virtually nil.
There is no question about the knowledge of surface warfare officers and the requirements placed on a cruiser or destroyer commanding officer. Unfortunately very few of these COs have served on board an MCM/MHC ship during their career, and the MIW training received by nearly all surface warriors is painfully thin when it comes to mine warfare and the requirements of that area.
Can the DDG/RMS combination replace the dedicated MIW force? Absolutely not. Can it be a valuable asset to the force commander? Yes, it can.