November16, 2006:
While the U.S. Navy is most responsible for clearing enemy mines,
it's the U.S. Air Force that will most likely deliver American naval mines.
B-52 bombers recently (November 3rd) held a mine planting exercise, dropping
92, 576 pound, Mk 62 bottom mines, and four 2,000 pound Mk 56 floating mines,
into coastal waters. A B-52 can carry 45 Mk 62, or a dozen Mk 56 mines per
sortie.
While
often ignored, these mines are a formidable weapon. But they just don't get any
respect. The historical record says otherwise. Modern naval mines were widely
used for the first time a century ago, during the Russo-Japanese war (1904-
1905). These were contact mine, floating in shallow water and kept in place
with an anchor and chain. When the tide was right, they would be just below the
surface, ready to explode whenever struck by a ship. Some 2,000 of these mines
were used to destroy sixteen ships.
During
World War I (1914-18), modern mine tactics were developed still more. Thousands
of mines were laid to provide defensive barriers against enemy movement in the
North Sea. Mines were used offensively by secretly placing them across known
enemy sea routes. More than 1,000 merchant and war ships were lost because of
the 230,000 mines used.
During
World War II, a total of 2,665 ships were lost or damaged to 100,000 offensive
mines. That's one ship for every 37 mines. Some 208,000 mines were used
defensively to inhibit enemy movement and tie up his resources.
Naval
mines achieved several striking successes during World War II. In the Pacific,
naval mines proved more destructive to the Japanese war effort than the atom
bombs. During a 10 week period between April and August 1945, 12,000 mines were
delivered by American bombers. These destroyed 1,250,000 tons of Japanese
shipping (670 ships hit, 431 destroyed). That's 18 mines for each ship hit. The
Americans had air superiority, so losses during these 1,500 missions amounted
to only 15 planes, most of them to accidents. Had these missions been flown
against opposition, losses would have been between 30 and 60 aircraft, plus
similar losses to their fighter escorts.
A
conventional submarine campaign was also waged against Japanese shipping.
Comparisons to the mine campaign are interesting. A hundred submarines were
involved in a campaign that ran for 45 months from December, 1941 to August,
1945. Some 4.8 million tons of enemy shipping was sunk. For every US submarine
sailor lost using submarine launched torpedoes, 560 tons of enemy ships were
sunk. During the mine campaign, 3,500 tons were sunk for each US fatality. On a
cost basis, the difference was equally stark. Counting the cost of lost mine
laying aircraft (B- 29's at $500,000 each) or torpedo armed submarine ($5
million each), we find that each ton of sunk shipping cost six dollars when
using mines and fifty-five dollars when using submarines. These data was
classified as secret until the 1970s. It indicates that mines might have been
more effective than torpedoes even if the mines were delivered by
submarine.
The
Germans waged a minelaying campaign off the east coast of the United States
between 1942 and 1944. Only 317 mines were used, which sank or damaged 11
ships. This was a ratio of 29 mines used for each ship hit. In addition, eight
ports were closed for a total of 40 days. One port, Charleston, South Carolina,
was closed for 16 days, tying up not only merchant shipping but the thousands
of men, warships and aircraft dealing with the situation. American submarines
also waged a limited mine campaign in the Pacific. For 658 mines used, 54 ships
were sunk or damaged (12 mines per ship). No subs were lost. Considerable
Japanese resources were tied up dealing with the mines. On the Palau atoll, the
port was closed by the mines and not reopened until the war ended. Even surface
ships were used to lay mines. Three thousand mines were laid by destroyers.
Only 12 ships were hit, but these were barrier fields, not the ambush type mine
fields that a submarine can create by sneaking into an enemy held area.
In
Korea during the early 1950s, the Soviets provided North Korea with 3,000
mines, many of 1904 vintage. These were used to defend Wonson harbor. It took
several weeks for UN forces to clear these at a loss of a dozen ships hit. Half
of these ships were destroyed.
During
the Vietnam war, over 300,000 naval mines were used, primarily in rivers. The
vast majority were not built as mines but were aerial bombs equipped with
magnetic sensors instead of fuzes. These bombs/mines used a small parachute to
insure that no damage occurred on landing. In shallow water these makeshift
weapons sat on the bottom and performed as well as mines. Haiphong Harbor was
actually mined with 11,000 of these "destructors," as the US air
force called them, and less than a hundred conventional mines. Haiphong Harbor
was shut down completely for months, and it took years to clear out all the
American mines. The "destructor" mine design was so successful, that it is
still in use, using more modern electronics, as the Mk 62 mine.
During
the 1991 Gulf War, the Iraqis laid over a thousand mines off the Iraqi and
Kuwaiti coast. The predominantly US naval forces did not have sufficient mine
sweeping resources to deal with this situation and had a helicopter carrier and
cruiser hit and damaged while trying to clear the area. This effectively
prevented any US amphibious operations, although the Marines were not going to
be used for a landing anyway. It took over a month of mine clearing after the
fighting ceased to eliminate all the mines. In the meantime, two U.S. warships
were damaged by these mines.
In
any future war, naval mines will again surprise everyone with how effective
they are. It is feared that terrorists might get their hands on some bottom
mines, but so far, there do not appear to have been any attempts.