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Wednesday, July 24, 2019

Wonsan Amphibious Assault And Mine Lessons

The US Navy has had two major post-WWII lessons handed to it regarding the link between amphibious assault and mines.  You may, already, be asking yourself, ‘Why two lessons?  Shouldn’t one major lesson suffice?’ .  For anyone but the US Navy, yes, a single major lesson should suffice.  But, I digress …

The two lessons were the Wonsan, Korea assault in 1950 and the aborted amphibious assault during the Desert Storm conflict (see, "Marine Corps in Desert Storm - The Great Diversion").  Let’s take a closer look at Wonsan.

The Navy Historical Center website very nicely summarizes the Wonsan operational rationale.

The great success of the Inchon Invasion led General MacArthur to order a second amphibious assault, targeting Wonsan on North Korea's east coast. After landing there, Tenth Corps could advance inland, link up with the Eighth Army moving north from Seoul and hasten the destruction of the North Korean army. Wonsan would also provide UN forces with another logistics support seaport, one closer to the battlefronts than Pusan and with greater handling capacity than tide-encumbered Inchon.

Wonsan's greatest value, though, was unintended: it gave the U.S. Navy a painfully valuable reminder of the fruits of neglecting mine countermeasures, that unglamorous side of maritime power that, when it is needed, is needed very badly. As Admiral Forrest Sherman, the Chief of Naval Operations at the time, remarked "when you can't go where you want to, when you want to, you haven't got command of the sea". This experience provoked one of the greatest minesweeper building programs in the Navy's history, one that produced hundreds of ships to serve not only under the U.S. flag, but under those of many allied nations. (1)


The Soviet Union had supplied North Korea with thousands of mines and technical advisors to help them plan and lay the mines using sampans operating at night.  The mines included 1904 era Russian contact mines and new magnetic influence mines sensitive enough to be triggered by a wooden minesweeper’s engines. (3)

Operation Wonsan was the clearance of mines from the Wonsan harbor and surrounding area in preparation for the amphibious assault.  The operation began on 10-Oct-1950, ten days before the assault was to begin.  The minesweeping and clearance operation was conducted under accurate artillery fire from the North Koreans.  On 12-Oct-1950, mines sank two US minesweepers, the USS Pledge (AM-277) and the USS Pirate (AM-275).  A Republic of Korea minesweeper, YMS-516, was blown up and sunk by a magnetic mine while conducting a clearance check sweep on 18-Oct-1950. (2)

SKorean Minesweeper Blown Up By A Mine


The landing force of some 30,000 Marines and soldiers arrived off Wonsan to begin the assault on 20-Oct-2019 but the mines had not yet been cleared and the assault force was forced to wait two weeks at sea while the mine clearance operation continued.

The minefields caused a 250-ship amphibious task force with 50,000 Marines and soldiers aboard to ‘yo-yo’ up and down Korea’s East coast for two weeks as NAVFE waited for Wonsan harbor to be cleared. (3)

Rear Admiral (RADM) Allan E. ‘Hoke’ Smith, TF Advance Force 95 at Wonsan was forced to message Washington,

“We have lost control of the seas to a nation without a Navy, using pre-World War I weapons, laid by vessels that were utilized at the time of the birth of Christ.” (3)

In the larger Korean conflict, five destroyers were severely damaged by mines and seven minesweepers were sunk. (3)

The incident offers some valuable lessons still immensely relevant today.

Clearance Under Fire – The mine clearance effort was greatly hampered by the North Korea artillery fire directed against the minesweepers.  We have totally ignored this aspect of MCM today.  We have too few MCM assets to allow for any combat losses.  We have no doctrine for protecting the MCM assets since our amphibious assault doctrine has the Navy standing 25-50+ miles offshore.  The LCS COBRA shoreline UAV is envisioned to function by slowly flowing back and forth, up and down the shoreline.  The life expectancy of the UAV will likely be measured in minutes.  We’re designing capabilities with no thought, whatsoever, to enemy resistance.

Sampans as Minelayers – This raised the question of how to counter what appear to be civilian craft?  Do we sink everything that floats and not worry about whether it was engaged in a military action or not?  Do we attempt to board every boat – while under fire?!  Do we allow the enemy a free ‘haven’ for mine laying?  This sounds ridiculous but the US has a long history of exactly that – allowing the enemy various types of free havens!  We have given this zero doctrinal attention.

Clearance Rate – I’ve talked about this repeatedly.  We simply do not have the right technology, the right number of assets, and the right mentality to conduct mine clearance in an operationally useful time frame.  This, alone, all but rules out amphibious assaults as a viable operation!

Technology Disparity versus Effectiveness – The US maintains a wide technological disparity over most potential enemies and yet we see time and again the stunning success of very low tech mines.  One can’t help but wonder if we’re pursuing the wrong end of the technology trail?  For starters, we need to acknowledge the incredible effectiveness of low tech mines instead of all but ignoring them as we have done for decades.  Next, we should be looking at simpler, more basic methods of mine clearance.  For example, instead of using exquisite technology to identify every mine, get its serial number, count the rivets on it, and neutralize them one by one, perhaps we should be looking at a method of indiscriminate destruction of every  object that even remotely looks like a mine – area destruction instead of precision destruction.  An example of such an approach would be to flood an area with a true swarm of small, suicidal underwater vehicles that just blow up everything they ‘see’ and don’t worry about what it was.  This is just one back-of-the-napkin idea.  I’m sure MCM professionals could come up with other ideas.

History is screaming lessons at us and the Navy is walking around with their hands over their ears.  We need to study history, learn the lessons, and change our ways.  Amphibious assault cannot occur in the presence of mines and we have no effective mine clearance capability.  The Marines, in particular, need to be pounding on this problem since amphibious assaults are their claimed reason for existence.





_________________________________

(1)Navy Historical Center website, “The Wonsan Operation, October 1950 --
Overview and Selected Images”, retrieved 21-Jul-2019,
https://www.ibiblio.org/hyperwar/OnlineLibrary/photos/events/kowar/50-unof/wonsan.htm



13 comments:

  1. Related excerpts from:
    http://www.g2mil.com/amphib-1.htm

    In addition, unarmed minesweepers are vulnerable if they try to clear lanes near shore without destroyer escorts and no one has explained why large unarmored LCACs (below) will not be sunk trying to shuttle material ashore from ships safely at sea. Another problem is moving fuel, which accounts for more than half the cargo needed ashore. In past invasions, hoses were run from ships just off the beach and fuel pumped to bladders ashore. Running a hose 20 miles offshore is impossible, but this problem is ignored.

    The very successful 1950 landing at Inchon, Korea provides an excellent example of an Amphibious Invasion. The port area was swept for mines as six Navy destroyers anchored off Wolmi-Do and began firing pointblank at targets there and along the Inchon waterfront. Their bombardment continued for about an hour followed by heavier gunfire from cruisers and more air attacks. North Korean return fire damaged three of the destroyers, killing one officer. Wolmi-Do and other nearby targets were hit again the following day, with good results, and again just before landings began on the morning of 15 September. (US Navy warships often fired on coastal targets so these attacks did not reveal the landing plan.) Marines seized the port of Inchon the first day to allow ship transports to land follow-on forces. This allowed the US Army's X Corps to quickly disembark and push rapidly inland to trap and destroy most of the North Korean Army fighting in southern Korea before it could withdraw northward.

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  2. A large part of the problem is that mine warfare isn't "sexy". The navy leadership is dominated by submariners (all nukes) , aviators (mostly fighter/attack jocks) and CRUDES surface types. None of those people know much--or care much about mine warfare. I fear we will not pay that attention until our lack is--once again--written in blood.

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  3. The Marines are abandoning the large amphibious assault mission.

    The Commandant just dropped the USMC requirement for 38 amphibious ships and 2.0 MEBs worth of lift.

    https://www.hqmc.marines.mil/Portals/142/Docs/%2038th%20Commandant's%20Planning%20Guidance_2019.pdf?ver=2019-07-16-200152-700

    "I do not believe joint forcible entry operations (JFEO)
    are irrelevant or an operational anachronism; however,
    we must acknowledge that different approaches are
    required given the proliferation of anti-access/area
    denial (A2AD) threat capabilities in mutually contested
    spaces. Visions of a massed naval armada nine nautical
    miles off-shore in the South China Sea preparing to launch
    the landing force in swarms of ACVs, LCUs, and LCACs
    are impractical and unreasonable."

    If this is the case, we should rewrite Title 10 to get rid of the port seizure mission and the dumb force level requirements.

    "(a) The Marine Corps, within the Department of the Navy, shall be so organized as to include not less than three combat divisions and three air wings, and such other land combat, aviation, and other services as may be organic therein. The Marine Corps shall be organized, trained, and equipped to provide fleet marine forces of combined arms, together with supporting air components, for service with the fleet in the seizure or defense of advanced naval bases and for the conduct of such land operations as may be essential to the prosecution of a naval campaign. In addition, the Marine Corps shall provide detachments and organizations for service on armed vessels of the Navy, shall provide security detachments for the protection of naval property at naval stations and bases, and shall perform such other duties as the President may direct. However, these additional duties may not detract from or interfere with the operations for which the Marine Corps is primarily organized.
    (b) The Marine Corps shall develop, in coordination with the Army and the Air Force, those phases of amphibious operations that pertain to the tactics, technique, and equipment used by landing forces.
    (c) The Marine Corps is responsible, in accordance with integrated joint mobilization plans, for the expansion of peacetime components of the Marine Corps to meet the needs of war."

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    Replies
    1. "The Marines are abandoning the large amphibious assault mission."

      Maybe, maybe not. The new Commandant made several intriguing statements in his guidance document but did not say that the Marines were out of the amphibious assault business. Instead, he suggested that the traditional amphibious assault fleet MIGHT no longer be the preferred approach. He didn't eliminate the mission, itself.

      Of course, this leads one to ask why we need Marines, at all?

      "The Commandant just dropped the USMC requirement for 38 amphibious ships and 2.0 MEBs worth of lift."

      Not quite. He stated that the Marines would no longer reference the 38-ship requirement. He also did not offer any alternative. Again, though, this leads to asking why we need an amphibious fleet, at all, and why we need Marines.

      This Commandant has opened the door to some serious issues for the Corps. It will be fascinating to see what answers he provides.

      Another major issue raised by this is, if the Marines are going to get out of the assault business (or significantly cut back on it) then why do they need their own air force since the original rationale was to support their amphibious assault efforts.

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    2. "Another major issue raised by this is, if the Marines are going to get out of the assault business (or significantly cut back on it) then why do they need their own air force since the original rationale was to support their amphibious assault efforts."

      Title 10 says they must have one by law.

      The Marines would say their air force is still useful for their forward presence mission.

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    3. "Title 10"

      I'm well aware of the law. Title 10 also stipulates that the Marines maintain amphibious assault capabilities and yet the Commandant seems to be suggesting that he will significantly cut back on that. If so, I repeat, why is air component still required or will it, too, be cut back significantly? This is a philosophical and rhetorical question. I know you don't have an answer. Only the Commandant has the answer and is not yet ready to share that, apparently.

      "The Marines would say their air force is still useful for their forward presence mission."

      The Marines would say a lot of things if it would get them budget share. Forward presence is not a Title 10 assigned mission.

      Delete
  4. Just read an interesting article in the tech section of fox news, on the Navy's future amphib operations concept.Got the usual unmanned and manned systems "networking", but the interesting part was their not looking at large scale assault anymore, they're talking about using the marine force more as a raider type force for smaller hit and run operations. They did say that more mine warfare assets were needed, but went back to the unmanned and ad on LCS crap.

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  5. "perhaps we should be looking at a method of indiscriminate destruction of every object that even remotely looks like a mine – area destruction instead of precision destruction."
    I think this is the key!!! Spending weeks sweeping an area pre-invasion is just not acceptable. Time is of the essence. While an amphibious landing is not going to be by suprise, every minute spent offshore is time the enemy can use to prepare. While the logistics and use of large amounts of suicidal mine killing drones is hazy, it seems like a good idea, and a good use of current, available tech, even if only a "first sweep" in advance of more discriminating manned MCM vessels are used just before amphib/fleet units appear. MCM is certainly somthing that needs a quantity over quality approach...

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  6. The amphibious assault landing craft could be fast hydrofoils, with foils that fold to allow the vessel to unload near the shore, or just drops the amphibious assault vehicles in the surf near the shore while still traveling on hydrofoils, like a low altitude drop from a cargo plane.
    Would the change the relative location of the ship to the detonated mine due to the velocity of a high speed vessel have a role in mitigating the effects of a mine detonation? The greater distance from the detonation, the lower the forces acting on the vessel.
    Also, the force would be directed on the hydrofoils and not the hull. The struts of the hydrofoil could be designed to act as energy absorbers.
    I did a quick search for any shock test results on the Pegasus class ships and came up empty. The Pegasus class could do 40 knots in sea state 5. A high speed landing craft that can operate above sea state 3 would be great.

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    Replies
    1. Mines are area denial weapons. They are designed to either deny an area or force the opposing force to move slowly and carefully through it. If they can sink some ships, that's great, but even just going off is going to disrupt the assault unless the assaulting force is trained to just plow through.

      Plus mines are one of those nasty technologies that are much easier to employ than to defend against. You mix up the type of mines (magnetic, contact, water-pressure, etc) and mix up their depth and now mine clearing is a much more complicated task. Plus mines are cheap and easily deployed.

      Even if you had a very high speed amphibious platform, the enemy would just optimize mines around that. And I'm really not sure 40 knots would be sufficient as no one has suggested that driving tanks through minefields at 60 mph would render the mines ineffective. And they don't need to sink the ship to force a mission failure. Which brings up back to shock testing of platforms.

      Historically, the US Navy has always hated mines and has spurned them. Mines don't reflect the traits the Navy desires to see in itself and its personnel. They are more like muggers in an alleyway than John Paul Jones.

      See https://www.nap.edu/read/10176/chapter/3#24 for example.

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    2. "unless the assaulting force is trained to just plow through."

      Damn the torpedoes. Full speed ahead!

      "And I'm really not sure 40 knots would be sufficient as no one has suggested that driving tanks through minefields at 60 mph would render the mines ineffective."

      Yeah, I'm dubious about that but I have no actual data or evidence to draw a conclusion one way or the other. There is a slight element of plausibility to the concept but I remain quite doubtful.

      "Which brings up back to shock testing of platforms."

      Spot on!

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    3. Shock absorbing hydrofoils sounds like a maintenance whore, even if you get them to work. But even with that it would definitely be good concept to try out on some prototype ships.

      Delete
  7. For a real wake up, read about Operation Starvation in 1945.
    https://en.wikipedia.org/wiki/Operation_Starvation

    And in North Vietnam, they shrugged off years of strategic bombing, but once Haiphong harbor was mined, they came running to the peace talks.

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