Naval Mine Warfare Returns to Spotlight Amid Middle East Conflict

As the U.S.-Iran war enters its second week with growing concerns over a prolonged conflict, reports emerged that Iran has deployed naval mines in the Strait of Hormuz, a critical chokepoint handling approximately one-fifth of global oil shipments.

CNN reported on the 10th (local time) that Iran began laying mines in the Strait of Hormuz in recent days and could deploy hundreds more. CBS reported that Iran is using small vessels capable of carrying two to three mines at a time for the deployment.

Following the outbreak of war, Iran declared it would "not let a single drop of oil out" and imposed a blockade, halting vessel traffic through the strait. As concerns over global oil supply disruptions intensified, the International Energy Agency (IEA) announced plans to release a combined 400 million barrels from strategic reserves.

U.S. President Donald Trump said on the 11th (local time) that the U.S. military had "eliminated 59 to 60" Iranian minelaying vessels in the Strait of Hormuz. However, this figure differed somewhat from foreign media reports citing U.S. Central Command sources that put the number at 16 vessels.

Iran's mine stockpile is estimated at between 2,000 and 6,000 units. The mines Iran has deployed to threaten vessels transiting the Strait of Hormuz have drawn international attention.

Naval mines can be deployed at desired depths using surface vessels or aircraft, making them among the most effective weapon systems for blockading or defending ports and sea lanes. Minelaying ships are essential for mine warfare operations that blockade enemy ports and cut off reinforcement and logistics access in the early stages of war.

Lessons from the Korean War

During the Korean War in October 1950, South Korean and UN forces that had succeeded in the Inchon landing attempted an amphibious assault at Wonsan, Gangwon Province, located 150 kilometers from Pyongyang. North Korea, with its main forces decimated by the Inchon operation, faced a desperate situation requiring it to prevent the allied landing at all costs.

North Korea deployed thousands of Soviet-supplied mines in the waters off Wonsan. The allied forces, not having anticipated North Korean mine deployment, were immobilized at sea for nearly a week, significantly slowing their advance.

This experience taught the South Korean Navy the importance of mine warfare. It is why the Navy's first minelayer, commissioned in 1998, was named "Wonsan."

South Korean Navy's Mine Warfare Fleet

The Navy currently operates two minelaying ships (MLS). The 2,600-ton "Wonsan" was commissioned in February 1998, followed by the 3,300-ton "Nampo" in June 2017.

The Wonsan (MLS-560), domestically built, was designed to serve as both a mine warfare command ship and a peacetime training vessel. At 104 meters in length with a light displacement of 2,500 tons, it is larger than Ulsan-class frigates. Four diesel engines provide a maximum speed of 22 knots (40 km/h).

Armed with one 76mm naval gun, two Nobong 40mm twin-barrel autocannons, and two Mk32 triple torpedo launchers, it possesses firepower comparable to Pohang-class corvettes. This armament is necessary because the ship may need to clear mines within range of enemy coastal artillery or provide cover for minesweepers as a mine warfare command ship.

Using mine deployment equipment installed at the stern, the vessel can rapidly lay hundreds of mines. It also carries mine-detection sonar and various mine-clearing equipment, along with a helicopter deck capable of accommodating large helicopters, including U.S. Navy MH-53 mine countermeasures helicopters.

The Nampo (MLS-570), at 114 meters in length with a light displacement of 3,000 tons, is significantly larger than the Wonsan. It has a crew of approximately 120 and a maximum speed of 23 knots (42 km/h). During wartime, it deploys protective mines to defend major ports and critical sea lanes while serving as flagship for mine warfare forces. In peacetime, it operates as a training ship.

Equipped with a helicopter deck for three-dimensional surface and aerial operations, stealth construction techniques reduce the vessel's radar and infrared signature. Key systems including the automatic mine deployment system, combat system, hull-mounted sonar, radar, torpedoes, and 76mm naval gun are domestically produced.

Mine Countermeasures Fleet

The Navy also operates ships designed to neutralize enemy mines. Six Ganggyeong-class mine hunters (MHC) and six Yangyang-class minesweepers (MSH) comprise the countermeasures fleet.

The Yangyang-class MSH, at 60 meters in length with a displacement of 850 tons, is 400 tons heavier and 10 meters longer than the 450-ton Ganggyeong-class. Enhanced mine countermeasures capabilities come from 20mm Vulcan guns, variable-depth sonar, unmanned mine disposal vehicles, and combined magnetic-acoustic mine sweeping equipment. These vessels also search for mines and depth charges that may remain on the seabed.

Minesweepers additionally conduct seabed surveys and collect oceanographic data, equipped with mine-detection sonar and variable-depth sonar systems for underwater acoustic measurement.

All these vessels belong to the 52nd Mine Warfare Squadron under the 5th Mine/Amphibious Flotilla based at Jinhae Naval Base. The squadron operates a total of 14 ships: two minelayers (one Nampo-class and one Wonsan-class) and 12 mine countermeasures vessels (six Ganggyeong-class and six Yangyang-class).

A military official said, "Minelaying ships, together with minesweepers, are central to managing the 'Q-Route' (quickest swept route) and securing sea lines of communication. The Q-Route is the channel for opening ports quickly during contingencies, while sea lines of communication are maritime corridors for major trade goods. Minelayers and minesweepers are responsible for the core mission of securing and protecting these routes."