by Ensign Chuck
|Editors Note: At first glance, there
may not appear to be much of a connection between the operations aboard submarines and
minesweepers. Upon closer inspection, however, many of the challenges faced by our surface
minehunting counterparts should be very familiar to submariners. For instance, both ships
have small crews that require extensive cross-training. On USS Champion (MCM-4), the
Sailor who runs the ships office is also a qualified Officer of the Deck.
Additionally, both submarines and minesweepers use sophisticated sonar systems to
prosecute quiet, challenging targets. And perhaps most importantly, both missions require
extraordinary technical competence and discipline to ensure success. Just as sloppy ship
driving could result in a burst of cavitation that might result in counterdetection of a
submarine, careless maneuvering of a minesweeper could quickly spell disaster.
The mine warfare mission has never been more important. Today, at least 30 countries manufacture naval mines, and at least 20 of those export the mines they produce. More than 50 nations have some degree of mining capability, and as Desert Storm showed, strategic deployment of inexpensive mines can wreak havoc on Navy surface and subsurface forces, Marine amphibious forces, and commercial ships as well.
"Mines are the most economical way to shut down ports and shipping lanes, or to stop an amphibious assault," says PN1(SW) Michael Hills. "Our job is to make sure that doesnt happen." In a nutshell, that is the mission of a mine countermeasures (MCM) ship like USS Champion (MCM-4), homeported at Naval Station Ingleside, Texas. Hills runs the personnel office on board, but he is also a qualified sonar operator, a Quartermaster of the Watch, and an underway Officer of the Deck (OOD) one of only two enlisted crew members to qualify as underway OOD. For Hills and his shipmates, neutralizing the mine threat is a task that provides an active role for everybody on board.
Avenger-class MCMs are fiberglass-sheathed and wooden-hulled to reduce their magnetic signature and use state-of-the-art systems like the SQQ-32 variable-depth mine detection and classification sonar and the SLQ-48(V) mine neutralization vehicle (MNV) an unmanned minehunting submersible to hunt, classify, and destroy mines. The ships are also capable of conventional minesweeping. And with a crew of only 80, "Everyone has to be qualified to do almost anything on board for us to fulfill our mission," said LCDR John Walker, Champions Commanding Officer.
Mine countermeasures ships like Champion are part of the "triad" of mine countermeasures assets that make up the Navys dedicated mine warfare force. Twelve 188-foot coastal minehunters (MHCs), all based at Ingleside; 14 224-foot MCMs, ten at Ingleside and two each forward deployed to Sasebo, Japan, and Bahrain; and the mine countermeasures command and control ship USS Inchon (MCS-12), also homeported at Ingleside, constitute the surface element. The forward-deployed MCMs are manned by Ingleside-based rotational crews. Two detachments of MH-53E "Sea Dragon" helicopters provide airborne mine countermeasures capabilities, and explosive ordnance disposal (EOD) mobile detachments constitute the underwater element.
Soon to join todays MCM "triad" is the Submarine Force, when its first unmanned underwater vehicle, the Near-Term Mine Reconnaissance System (NMRS) becomes operational later this year after at-sea testing on a Pacific Fleet SSN.
Champions role in this mix is straightforward. "We hunt when we can and sweep when we must," Walker explained.
Mines come in two general varieties, contact and influence. For detonation, contact mines require a physical impact between the target and the mine itself, and are either moored in the mid-water region to an anchor on the bottom, or simply set adrift until they encounter a target. (Drifting mines, however, were outlawed by the Hague Convention of 1897.) Influence mines are triggered by the close proximity of nearby targets by sensing changes in the ambient acoustic, electromagnetic, or pressure fields caused by a ships passage. These can be configured as either moored or bottom mines.
During a typical minehunting scenario, Champion will move slowly into an area suspected to contain mines and use its sonar to locate "mine-like" objects in the water column and on the bottom. Once a suspicious object has been detected, the MNV is deployed to locate it precisely and determine whether or not the contact is a mine. Connected to Champion by an umbilical cord, the MNV is piloted remotely by a Sailor with a joystick in the Combat Information Center (CIC), guided by the vehicles own sonar and associated video cameras.
For moored mines, the MNV uses manipulator arms to attach small explosive charges to the mooring cable, which when severed, will allow the mine to rise to the surface. For bottom mines, the MNV carries somewhat larger charges, which can be dropped close to the mine and detonated after the MNV has moved a safe distance away.
"Operating the MNV is a prestigious job," said MN2(SW) John Frederick, a three-year MNV pilot now assigned to his second MCM. He noted that it takes significant experience to "drive" the MNV successfully and to learn the characteristics of various mine targets. Armed with those skills, however, there is nothing quite like piloting the MNV on a successful mission. "The MNV and sonar are our main battery our bread and butter. Its sweet when I find that mine and know that Ive done something not everyone can do."
The sonar on Champion is similar in its essentials to the systems used on submarines, according to LTJG Chris Wolking, a former STSC who served on the USS Alabamas (SSBN-731) Gold crew. "The fundamentals are the same. But the big difference between what we do and what submariners do is in the size of the target."
"Were looking for something extremely small," Walker added. "Instead of looking for a 4,000-ton moving submarine, were often searching for something as small as a basketball and it doesnt move!"
Navigation System (PINS) allows
When there is not enough time for minehunting, and it is necessary to accomplish mine neutralization as quickly as possible, the ship deploys its minesweeping gear. Just as there are two general types of mines, there are two broad categories of sweeping, mechanical and influence. Mechanical sweeping requires the towing of sweep cables behind the ship, diverted outward from the centerline by paravanes and otter-boards. These cables, in turn, bear explosive cutters, which detonate automatically when they encounter a mine mooring cable, thus severing it so that the mine floats to the surface for disposal by the ships embarked EOD detachment. In influence sweeping, either heavy electrical cables are towed for generating a large magnetic field, or acoustic noisemakers are deployed, to simulate the magnetic or acoustic signatures of real ships and "fool" the mines into detonating.
Whether hunting or sweeping, the small crew size requires constant cross-training to keep watchstations manned during condition 2MH (minehunting). "I cant think of better billets than those on an MCM," said PN1 Hills. "If someone is willing to learn, the opportunities are limitless. This is my first sea tour. I came here to get my warfare pin and walked away with a whole lot more."