At the end of 2016 China put another Type 082B (Wozang class) minesweeper into service. This was the third of these new ships to enter service in the last 18 months. The first one appeared in 2005 and there are believed to be five in service. Each can serve as a mothership for three 100 ton USV (unmanned surface vessel) mine sweepers. The Wozang’s are an updated version of the 400 ton Type 082 (Wusao class) that first appeared in 1985. About a dozen of these entered service and, as they were the first modern “mine hunter” design they went through a lot of changes before the first of the B version showed up in 2005. The Type 082B is a 575 ton non-metallic ship that is 55 meters (179 feet) long. Top speed is 46 kilometers an hour with a crew of 50. It is equipped to detect and destroy surface and bottom mines and is only armed with a twin 25mm autocannon and small arms for the crew. It draws only 3.3 meters (11 feet) of water, enabling them to operate close to shore. This ships can also carry and deploy six naval mines.
The only equivalent American ships are the Avengers, which began appearing in 1987. These are 1,300 ton, 72.3 meter (224 foot) long ships that draw only 4.8 meters (15 feet) of water. The crews are trained in navigating shallow areas. The Avengers are armed with two .50 cal. (12.7mm) machine guns, two 7.62mm machine guns, two 40mm automatic grenade launchers, and have a crew of 84.
While China has continued to upgrade its mine clearing (or “countermeasures”) ships the United States and most Western navies have not been ignoring the naval mine threat but have instead shifted to greater use of use of USVs and UUVs (unmanned underwater vessel) as well as unmanned mine detecting “sleds” towed by helicopters. The remotely controlled USVs and UUVs detect and destroy mines. China has yet to introduce much along these lines.
Naval mines remain a serious danger that even China is paying more attention to. As China becomes more dependent on raw materials and fuel being shipped in and exports shipped out, naval mines become more of a threat. While often ignored, naval mines are still 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 over a century ago, during the Russo-Japanese war (1904- 1905). These were contact mines 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 the Russo-Japanese war. That's one ship lost for every 125 mines used.
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. That's over 200 mines used for every ship lost. 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 ten week period between April and August 1945 12,000 mines were dropped off the Japanese coast 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. Still, these air delivered mines proved to be a devastating weapon.
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 U.S. 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 U.S. 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. This 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.
During World War II there was a major effort to develop better mine clearing methods. These efforts ended in 1945 but were resumed because of the experience in Korea during the early 1950s. The Russians had provided North Korea with 3,000 mines, many of 1904 vintage. These were used to defend Wonson harbor (on the east coast of North Korea). It took several weeks for UN forces to clear these, at a loss of a dozen ships hit. Half of these ships were destroyed. When the Korean War ended in 1953 the United States and Western nations in general realized they could no longer ignore naval mines.
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. In North Vietnam, Haiphong Harbor was actually mined with 11,000 of these "destructors," as the U.S. 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 U.S. 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 U.S. 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 2003, the Iraqis again tried to use mines, but were hampered by prompt American, British, and Kuwaiti action.
All this provided more encouragement to develop and build more effective mine detecting and clearing equipment. Despite that 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.