Thursday, May 18, 2017

Offensive Mine Warfare - Operational Usage

We previously reviewed the Navy’s inventory of mines (see, "Offensive Mine Warfare") and noted that there are only two active versions:

  • Quickstrike – converted general purpose bombs of 500, 1000, and 2000 lb sizes
  • SLMM (Submarine Launched Mobile Mine) – modified Mk37 torpedo

We further noted that the delivery options for these mines are quite limited.  B-1 and B-52 bombers have mine laying capability but rarely train for the mission.  Submarines theoretically have the capability but have little capacity and apparently do not regularly train for the mission.


Mk 65 Quickstrike Mine Loading Onto A B-1 Bomber


How does this matter?  Well, that brings us to the operational employment of mines.  In order to understand their employment, we need to have an understanding of their historical use.  Without attempting to document a comprehensive listing, here are some notable historical uses by the US military.

In WWI, over 6000 mines were laid as part of the North Sea Mine Barrage, intended to inhibit U-boat movement into the Atlantic convoy lanes.  A US Navy group of ten converted commercial ships took part in the effort, aided by the Royal Navy.

Defensive minefields were laid up and down the east coast of the US and into the Caribbean during WWII.  Navweaps website states that 20,000 mines were laid defensively in US waters alone (2).  As far as is known, no enemy ship was sunk by the approximately 20,000 mines used in defensive minefields placed in US waters (2).

Also in WWII, US submarines planted mines in Japanese harbors and shipping lanes.

“[During WWII] US submarines planted a total of 576 Mark 12 mines and 82 Mark 10 mines in 36 fields. Of these, 421 mines planted in 21 of the fields sank 27 ships of about 63,000 tons and damaged 27 more of approximately 120,000 tons.” (2)

By 1945, the Army Air Force was devoting considerable resources to the mining role, with 80 to 100 B-29s based at Tinian being used to mine the home waters around Japan. These B-29s could carry seven 2,000 lbs. (907 kg). or twelve 1,000 lbs. (454 kg) mines. Starting in March 1945 and continuing until early August, 4,900 magnetic, 3,500 acoustic, 2,900 pressure and 700 low-frequency mines were laid. These mines sank 294 ships outright, damaged another 137 beyond repair and damaged a further 239 that could be repaired. In cargo tonnage, the total was 1.4 million tons which was about 75% of the shipping available in March 1945.

“Between January and March 1945, B-29s also closed the approaches to Singapore, Saigon and Camranh Bay harbors by magnetic mining.” (2)

Smaller WWII Aircraft were also used to lay mines.

“Avenger and Ventura aircraft could carry a single mine and in 1944 Avengers closed Palau harbor by mining the entrances. They then sank all 32 ships in the harbor with conventional bombs and torpedoes. A total of approximately 100 ships were sunk or badly damaged in the Pacific during the war by mines laid by Navy aircraft.”

This was a classic example of sealing the escape route and then destroying the trapped vessels at leisure.

We see, then, that a major conflict could be expected to require many tens of thousands of mines.  I can’t recall ever seeing an inventory summary of how many mines the US Navy has but I strongly suspect it’s not a large amount. 

Further, note that mine laying objectives are two-fold: 

  • One, is an offensive minefield intended to close enemy harbors, approaches, and navigational chokepoints.

  • Two, is a minefield intended to provide defensive protections around friendly harbors or invasion site approaches.


As a bit of a sidenote, here are some interesting examples of mine laying vessels used by the Navy in WWII.

  • The Navy developed a dedicated mine laying destroyer in WWII, the Robert H. Smith class, which was a variant of the Sumner class destroyers.  Twelve ships were built in late 1943 and early 1944.  Mine tracks ran along both sides of the ship and each track could hold 60 mines.  The mines were released over the stern, similar to the way depth charges were dropped (1).  Astoundingly, none of the ships ever laid a mine!

  • The Navy did utilize a converted cargo ship, USS Salem CM-11, to lay 202 mines of Casablanca in late December 1942.  Salem also laid 390 mines off Gela, Sicily in July, 1943 in support of the Sicily invasion.

  • USS Weehawken, CM-12, originally a 1920 car ferry, was converted to a mine layer.  The ship laid defensive mine fields of Casablanca in December 1942 along with USS Salem and USS Keokuk.  Following that, she laid minefields off Gela, Sicily in July 1943.

  • USS Keokuk, CM-8, was also a conversion of a commercial ship built in 1914.  Wiki suggests that the ship engaged in mine laying along the Atlantic coast of the US during the summer of 1942.  The ship also participated in the mine laying off Casablanca and Sicily along with Salem and Weehawken.

  • USS Terror, CM-5, was the only purpose built Navy minelayer of WWII.  She laid defensive mines off Casablanca in December 1942.  The ship also operated in the Pacific, laying mines in the Pacific Marshall Islands in March and April 1944 and around Ulithi in September of 1944.  She also acted as a tender for numerous small craft engaged in mine laying and mine sweeping.

  • Several Clemson class 4-stacker destroyers were converted to mine layers during WWII.

We see then, that mine laying has, historically, never been given much priority in terms of developing dedicated mine laying vessels.  When the need arose, the Navy converted commercial vessels or adapted destroyers already in production.  This can be interpreted one of two ways:

  1. The Navy has failed to recognize the importance of mine laying and is continually caught short when the need arises or,

  1. Mine laying is a simple and generic enough exercise that there is no need to maintain dedicated vessels and when the need arises, any suitably sized vessel can be adapted to the task.

I tend to think it’s a combination of the two with a leaning towards the relatively undemanding nature of mine laying and the underlying economics of conversion versus maintenance of a dedicated mine laying force.  Of course, this only applies to mine laying in relatively uncontested areas.  Mining contested areas like enemy home waters requires either stealth (submarine mine layers) or stealth/speed (aircraft) in order for the laying vehicle to survive.  This suggests the need for maintaining a dedicated mine laying vehicle for contested areas.  Converted vehicles simply will not have the stealth and/or speed necessary for the task.

Let’s return, now, to the operational aspects of offensive mine warfare.

History tells us the kinds of mining that will be required.  So what kind of targets/areas should we be planning for in a major war?

Iranian harbors – a relative handful of mines could effectively shut down Iran’s entire navy (such as it is) and commercial shipping.

NKorean harbors – war with NKorea will be a land and air war.  I can foresee no reasonable need to conduct an amphibious operation but the ability bottle up NKorea forces and effectively blockade Russian and Chinese resupply vessels would be worthwhile.

Russian harbors, approaches, and navigational chokepoints especially those used by the Russian sub fleet, if mined, would deal a critical blow.  Mining of the so-called SSBN bastions would deny Russia the use of its ballistic missile submarines and completely disrupt one of their major strategic foundations.

Chinese harbors and navigation chokepoints are particularly susceptible to mining.  The narrow waters and sea lanes between the first island chain islands provide ideal opportunities to restrict Chinese submarine and surface ship movements and island resupply efforts.  An effective mine laying program would largely bottle up China’s fleet and remove at least one aspect of the A2/AD zone.

In summary, the patterns of use of offensive mine warfare are clear as is the need in future conflicts.  What is far less clear is the capacity of the US Navy to wage effective offensive mine warfare given the lack of mines (inventory), the dearth of mine laying platforms, and near total disregard for offensive mine warfare tactics and training.  As is so often the case, the US Navy is focused on the big, shiny toys and is neglecting a far more powerful and effective weapon.



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(1)Destroyer History Foundation website,

(2)NavWeaps website,


18 comments:

  1. Maybe the answer is in your previous post but what about the MK-60 CAPTOR moored mine (uses Mk-46 torp)? I take it the Mk-55 2000lb'er, what we used to call $hitcan (big time drag count), is no longer in service also? If true I can assume the mine warfare is not a CVW (F-18 A-F) or P-3/P-8 mission anymore? Is that really true? No more Santa Rosa or Charleston MINEXs?

    Agree toatlly that Mine Warfare denial is a great way to pre-empt a fight or curb hostilities. I remember the response when we aerially mined Haiphong harbor in 1972.
    Stealthiest and probably most effective way to mine is by sub. Fastest way is by jet but that takes a total ECM and deception package to pull off.

    BTW since last century use of mines is considered and "act of war".

    b2

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  2. I think you are selling their preparations short. It seems pretty clear that most mining would be done via aircraft and that most mines are going to be converted GP bombs. The navy seems to have done a good job at piggy backing on new-technology (GPS guided mines/adding small wings to mines to increase the range from which they can be dropped) http://thediplomat.com/2017/05/the-antiship-mine-gets-new-wings/

    Because these are converted GP bombs, it seems like the limiting factor, if any, is going to be the fuses (unless we anticipate running out of JDAMS...which is arguably possible).

    Additionally, because the mines are converted from GP bombs, it doesn't seem like the bombers would need any particularly specialized training (beyond training to drop bombs in potentially contested airspace).

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    1. "seems pretty clear that most mining would be done via aircraft"

      That does not seem clear to me, at all. Given that our two mine-capable aircraft are the big, slow, lumbering B-52 and the big, fast, but not particularly stealthy B-1, I don't see aircraft as being particularly survivable in the mission. Consider the case of mining Chinese harbors. Do you see those aircraft having any chance of surviving a thousand mile penetration of the Chinese A2/AD zone to lay their mines? I don't. The B-52 wouldn't make it a hundred miles and the B-1 not much more. The gliding mines extend the mine laying range a bit but not by any useful amount compared to the penetration distance and the capability of the threats.

      You seem to be assuming we'll have uncontested aerial supremacy and our aircraft will be able to fly wherever they want, unhindered. You might want to mentally 'game out' how B-1/52 are going to penetrate hundreds or thousands of miles of contested airspace against modern radars, stealth fighters, naval surface to air missiles, etc.

      I'm not saying that we can't use aircraft for mine laying but it will be limited to uncontested areas. Unfortunately, the real areas you want to mine WILL be contested.

      Think about this and see if you change your thinking. If you still think we all set, tell me how it can happen against the threats I've described.

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    2. The counter argument, I think, is that any other potential mine-layer is going to be wildly less survivable, unless it is a B-2 (possible although they may have better things to do) or a submarine (possible but limited in terms of numbers of mines it is able to carry). Any difficulty in getting an aircraft to survive laying mines is going to be magnified 100x if you are trying to drop the mines from a ship.

      I also do think that it is possible for an aircraft to successfully mine choke points within a few hundred miles of the Chinese Coast (especially with a B-1...it is fast) and mines are not generally used against military ships, but against commerce, you can lay mines in some straights/approaches and really scare off commercial ships.

      And, if not, aircraft (or submarines...although those are a possibility), what other options are there? You could further extend the range of the mines by adding an engine, but at that point you are starting to look at cruise missile prices...and in that case, why not focus on shooting the missiles at the ships rather than using them to drop mines?

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    3. "The counter argument, I think, is that any other potential mine-layer is going to be wildly less survivable, unless it is a ... submarine "

      You just countered your own counter-argument! A sub is the only viable, survivable, deep-penetrating mine laying platform. One of the points of the post was to note the lack of capability and almost total lack of training and preparation for that mission.

      This is not an either/or argument. No one is suggesting that aircraft do not have a role in mine laying, only that they are not survivable in a deep-penetrating mine laying mission.

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    4. "mines are not generally used against military ships"

      Of course they are!! Mines are used against any ship. Numerically, there are more merchant ships so, in a war, there would be more merchant ships mined than naval but that's simple numbers. Also, naval ships tend not to pass through predictable, narrow passages as merchant ships do so they are somewhat less exposed to mines.

      The post presented perfect examples of mining a harbor entrance, sealing the ships (merchant and military)) in, and then destroying them at leisure.

      The US Navy has suffered more damage from mines than any other weapon since WWII.

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    5. Any idea how many mines the Virginia or Seawolf class can carry?

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    6. Wiki says that a Seawolf could carry 100 mines, not sure if that is with still some torpedoes on board or if you removed all torpedoes and only carried mines.

      Interestingly, reading Wiki, it said that in 2002, Royal Navy pretty much was out of stocks of mines...you have to wonder how well a service can lay mines or fight mines when you don't have them anymore in stock!

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  3. Its old footage but shows how the B-52G's used to practice mine laying.
    https://youtu.be/un4ImREkJNY

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  4. This seems like a good justification for some forward deployed aip subs.

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  5. It's easy to see why USN doesn't like mines, there are cheap and they work!

    Have the Russians or Chinese done any recent investing in mines? I can see NKorea and Iran spending some money on mines, very cheap, not a lot of high tech, well within their industrial capacity to produce and major pain to operate and clean up for USN.

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    1. A 2009 Naval War College report cites a Chinese mine inventory of 50,000 - 100,000. China is very active in both offensive mine warfare and MCM.

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  6. 50-100K? Holy Cow!

    We definitely should take an interest in mine warfare.

    Especially since it would seem that its a vulnerability to the Chinese we can exploit. Their economy is heavily dependent upon export and sea trade.

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  7. Re carrier air wing: Mines laid from go fast jets like F-18 and before that the old A-6, S-3, A-7 or even P-3 minelayers were very accurate dropped from low altitude (under radar) hi-speed, and the most important factor- One Pass.. It also takes a lot of practice like all precision drops and I am sure GPS makes it more accurate. Don't forget about that aero drag I mentioned above... But of course none of us know whether we still have that airwing mission in our tool bag from the responses above. Right? Think Haiphong Harbor in '72:

    https://en.wikipedia.org/wiki/Operation_Pocket_Money

    "Glide mines" are as far/close to operational use as "glide ASW torpedoes" probably. What you scan in the glossies may not be 100% valid...

    Mine laying is also psychological warfare. After one deploys the mines one informs the adversary or waits until he discovers it. BTW, how is the PRC situated for defensive mine sweeping?

    Oh yeah did I remind you that mine warfare is an act of war? IMO, a mission not to be taken lightly or used only as a deterrent to war.

    B2

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  8. "Oh yeah did I remind you that mine warfare is an act of war? IMO, a mission not to be taken lightly or used only as a deterrent to war."

    Mine laying, like a blockade, should only be used when you are ready to go to war.

    But when we are there, it should be a priority mission against a rival who depends upon the sea.

    Again, with this mission, the lack of legs of the current airwing hurts us.

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  9. May It be cost effective a simplified unmanned minelayer, that sails to a setted GPS point and deliver them? After that she could try to get back for a new mission anyway.

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  10. Have you seen this, stand-off precision aerial mining? http://thediplomat.com/2015/12/new-wrinkles-in-maritime-warfare/

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    1. Yes, I'm familiar with this. It's a nice capability in certain situations but has a couple of significant limits.

      -The standoff distance (40 miles from high altitude) is very small compared to the range of, say, the Chinese A2/AD zone which is hundreds to a thousand miles or more. For a B-52/1 bomber who has to penetrate (and survive) a thousand mile defensive zone in order to reach the mine launch point, cutting 40 miles off the trip is insignificant. Further, in order to achieve the 40 mile standoff, the aircraft has to be at high altitude which makes it very visible to enemy sensors and decreases the chance of survival. Lower altitudes decreases the standoff distance.

      Similarly, the 40 mile standoff distance is useful against short range AAW missiles but medium and long range missiles can easily reach 40 miles and large targets like the B-52/1 are not survivable.

      Thus, the 40 mile standoff, while potentially useful in some situations, is not a game changer.

      -The air dropped Quickstrike mines are just converted bombs and are limited to shallow water (they sit on the bottom). Thus, the regions where standoff, air dropped mines are useful is limited. Harbors, river mouths, and the like are potential targets but deep sea mining cannot be done with these weapons.

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