Naval mines as a defensive barrier of Taiwan: a not so crazy hypothesis

(To Andrea Mucedola)

At the end of World War II the Americans launched the operation starvation, a mine conducted by the United States Army Air Forces to disrupt Japanese naval activities. The mission was initiated at the insistence of Admiral Chester Nimitz and was assigned to US Army General LeMay who, in April 1945, employed about 160 aircraft of the 313th bombardment wing, with the order to initially lay 2.000 mines.

Mining was carried out at night by B-29s Superfortress at moderately low altitudes, basing minefield-laying accuracy on simple radar measurements. From 27 March 1945, 1.000 influenza mines were initially dropped, reaching 17.875 mines by aircraft, 3010 by ships and 1.020 by submarines by the end of the campaign.

This type of underwater weapons, despite never wanting to give a great resonance to their effectiveness, proved to be the most effective means of countering Japanese shipping during World War II. In terms of damage per unit, naval mines outnumbered submarine torpedoes and air strikes from aircraft carriers or land.

Someone ventured the thesis that, if the result were accepted and the war continued for another year, there would have been no need to use the atomic bomb on Hiroshima.

The use of naval mines by the Americans also occurred in Vietnam, with the mining of Haiphong Bay in May 1972. The operation contributed significantly to forcing Hanoi to the negotiating tables and obtaining a reasonable agreement to cease war.

Many years have passed and we could make a risky assessment: What would be the most effective policy in the Indo-Pacific in the event of a frictional conflict between the US and China?

Clearly we are in the world of hypotheses and, fortunately, the conditions for a conflict are still far away. Analyzing the areas of the South China Sea we discover that they are largely subject to mines and, in the case of the laying of these devices, merchant traffic could be forced onto well-defined transit channels.

The advantage of laying defensive minefields around Taiwan would discourage Chinese access to the strait of the same name, preventing it from penetrating Taiwanese territorial waters; in practice it could be a first defensive measure, highly dissuasive, in a situation of open conflict with China. 

Geographically, the Taiwan Strait is shallow and narrow, approximately three hundred kilometers long with an average width of 180 km (130 km at the narrowest point). Its average depth is sixty meters (up to a maximum of 100 m) and this means that it is perfectly and easily mineable. Furthermore, shipping traffic in the strait is centered around an 8 km wide and approximately 20 m deep strip of water, making civilian traffic particularly at risk from the use of naval mines.

The United States, according to the latest statements, would support Taiwan in the event of a Chinese attack. The question we can ask ourselves is how. A clash of fleets would be extremely violent, involving modern air-sea and surface units where, although the difference would be made by their technology and training, the losses would be huge. In any case, it would be an extreme and dangerous solution for international stability.

Alternatively, the use of the old but still effective Quickstrike mines could be envisaged, an alternative and less direct solution than a clash between naval groups. A defensive mine of the South China Sea by the Americans, in support of Taiwan, would slow down possible Chinese actions.

Obviously it could not exclude a priori a subsequent step which could include offensive actions against Chinese merchant traffic (60% of Chinese trade travels by sea and maritime imports into China account for a quarter of global maritime trade) and the major ports of Xiamen, Quanzhou and Fuzhou. Considering that in 2018 China moved 5,5 million tonne-kilometres of cargo by ship compared to 2,7 million tonne-kilometre by rail, the damage of a blockade of sea lanes would be unacceptable.

Furthermore, since it is not convenient for anyone to come to a direct confrontation, the carrying out of preventive actions, for defensive/dissuasive purposes, could be decidedly advantageous. Among them we could hypothesize the use of naval mines.

There are two questions we can ask ourselves:

  • Would the US military be able to do it quickly?
  • Would China be able to operate promptly for the demining of the affected areas?

Let's start with the first question. Surprisingly, the US Navy has no specialized naval minelaying capability other than the limited use of a few submarines. The only naval mine currently available in US arsenals is the older MK 67 Submarine-Laid Mobile Mine (SLMM), propelled by a modified Mk 37 torpedo. 

While the Mk 67 (photo) is the only mine in the US Navy's stockpile that can be laid clandestinely from long distances, it is based on technology that dates back to the 60s and cannot be launched from modern class submarines. Virginia. The US NAVY inventory still includes the quick strike, a family of shallow-water aircraft-dropable mines that can be used against ships and submarines.

Basically versions quick strike Mark 62, Mark 63 and Mark 65, respectively of 500, 1.000 and 2.000 pounds, are bombs converted into naval mines which, despite their age, are still effective in countering merchant traffic in sensitive maritime areas.

Given the geographical characteristics of the China Sea around Taiwan and the USN's current mining capabilities, the quick strike (photo) could therefore be used against merchant traffic but also submarines and opposing military ships. In particular, the 500 lb version could be more than sufficient as it is capable of causing damage to merchant traffic. From a strategic point of view, their use would make it possible to carry out a balanced dissuasive action, using inexpensive resources. Also, considering that the first mission would definitely be covert, the number of mines that can be thrown would be unknown to any opponents in the area who could only try to contain subsequent layings. 

Obviously the number of mines laid would be determined by the aircraft available as a function of their payload capacity. From a point of view of employment, the Taiwan Strait is within the reach of the bombers stationed in the US air bases in Japan and Guam which could carry out mining missions even without the need to refuel, transporting and laying about 3.000 mines in a single mission ( an amount however not necessary for deterrence that could be counterproductive, in terms of Chinese reaction).

What could be the Chinese reaction?

A minemining in Taiwan's territorial waters would raise protests from China but it would be nonetheless legitimate under international law.

Another thing would be a mine in international waters (especially in those disputes) which would raise the level of tension. The Chinese response could be violent, with targeted attacks, in a geopolitical escalation that would not however solve the problem of blocking merchant traffic (the explosion of a single mine along a maritime communication route is enough to block it). At this point we should go back to the negotiation tables to agree on the necessary remediation which would take a very long time.

How long would it take for the Chinese navy to clear the mined areas?

In addition to the number of mines laid, China's timing response would depend on the number and effectiveness of minesweepers/minesweepers available. China has fourteen Type 81 minesweepers/minesweepers ( Wochi - photo) and sixteen minor Type 82 minesweepers which, apparently, would only be able to counteract moored contact mines (therefore… practically useless).

Additionally, the Chinese Navy owns:

  • Type 529 minesweeper/class minesweeping drones Again and class wonang; Type 8101 200-ton auxiliary minesweepers;
  • Type 8105 auxiliary minesweepers of 366.82 tons;
  • Type 8154 600-ton minelayer/auxiliary minesweeper;
  • Type 792 auxiliary minesweeper

Supposing that a third of the ships is not available (for maintenance) one could hypothesize a real availability of around twenty mine countermeasure units, most of which with technologies that are certainly not state-of-the-art. The Chinese clearance estimate could therefore be compressed between 0,8 to 2 mines per unit employed per day, similar to that obtained at Wonsan (where the eighteen American minesweepers achieved a rate of 0,83 mines cleared per day).

Although the Wonsan reclamation took place in the 50s, the effectiveness of the means may not have improved. With a similar progress ratio, even considering no minefield refresh operations by the Americans/Taiwanese, the clearance times would therefore be very long.

In conclusion, the descending effects of a naval mine for defensive purposes in the South China Sea could be an interesting dissuasive political solution, avoiding the use of more aggressive means of law enforcement…

The international situation is constantly evolving and it is only hoped that common sense on both sides will prevail.

Photo: US Navy / web

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