Wednesday, April 3, 2024

Patria NEMO Mortar

There is a constant call from some naval observers to mount land weapons on boats and small vessels as a substitute for proper naval gun support.  Weapons of choice include MLRS and mortars, among others.
 
The reality is that most attempts to adapt land weapons to naval use have failed for various reasons.  For example, the Germans attempted to mount a MONARC self-propelled howitzer turret on a frigate but the adaptation to the corrosive maritime environment proved more difficult than anticipated and the program was cancelled.[3]
 
Maritime adaptation issues aside, one has to wonder what the concept of operations (CONOPS) is for these kinds of weapons on small boats.  For example, the Patria NEMO 120 mm smooth bore mortar has been mounted on small boats.  Currently, six UAE Ghannatha fast troop transport boats each have a single NEMO mortar.
 
NEMO Mortar on Ghannatha Boat

Let’s consider that example.
 
The UAE boats are very small at 27 m (88 ft) and have a GEM elettronica coastal surveillance radar.
 
The NEMO mortar has a 3 m barrel and is claimed to be compatible with any standard or GPS-guided 120 mm smoothbore round.  As an example, the NAMMO 120 mm High Explosive Round has a 2.2 kg (4.8 lb) explosive weight in a 13 kg (28.6 lb) shell.[1] 
 
The mortar has a range of around 10 km (6 miles), sustained rate of fire = 6 rds/min, and a magazine of typically 50-60 rds.[2]
 
Fire control requires a forward observer.
 
 
Discussion
 
What is the CONOPS for a single naval mortar with a limited magazine and slow rate of sustained fire?  Even operated in groups it’s a limited firepower capability unless used in groups of hundreds.  Further, the rounds have limited destructive effects due to small warhead.
 
Consider that an amphibious assault operation requires many thousands of rounds of heavy naval gunfire in order to provide effective destruction and suppression.  A NEMO boat’s 50-60 rounds just aren’t going to accomplish much in that scenario, even in squadron strength.
 
So, what scenario would a mortar boat be useful for?
 
The only viable scenario is support for an isolated, small ground unit.  This would suggest a miniature raid or extraction type operation.  That’s fine for that scenario but the general usefulness seems quite limited.  A country that conducts a lot of riverine type work, for example, might find a boat mounted mortar useful but the US simply doesn’t do that type of operation anymore.  The wisdom of the elimination of that type of capability is debatable but that’s a different subject.
 
Proponents of mounting land weapons on small vessels are likely caught up in the allure of the technology rather than the reality of the CONOPS.
 
 
 
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21 comments:

  1. I imagine that latching onto concepts like these (small craft with limited combat ability and independent sensor suites) is meant to be used to justified the continued expenditure and procurement of small autonomous vessels.
    By saying "Hey, we need small vessels to provide Naval Gunfire support!", one could then argue that small autonomous boats could possible be used for that purpose. Effectively, its designing/selecting a particular task that a different meandering project could possibly perform, and then using that task to justify continued development of that project.

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  2. Our neglect of a Riverine force is a valid concern. Wha might have been if we'd chosen to dominate the Tigris and Euphrates during our entire fiasco in Iraq. Is this the best solution for the U.S., maybe not. It sure seems like a better 120mm mortar solution than the Marines adopted and ditched.

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    1. "[What] might have been if we'd chosen to dominate the Tigris and Euphrates during our entire fiasco in Iraq"

      What is it that might have been? I ask this sincerely. I don't know. Did our enemies use those rivers for transportation/movement? Were there military objectives we could have better accomplished via riverine forces?

      So many people become enamored of certain platforms or equipment without actually figuring out a concept of operations that makes sense. This is exactly what our Navy does.

      Give me some specific examples of things you think riverine forces could have accomplished and what benefit they might have conferred.

      Not disagreeing, at all. I'd love to explore this. Lead the way!

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    2. The major rivers in Iraq would have almost certainly been used by hostile forces to move fighters and resupply. A big portion of them are navigable by small craft, large enough to either carry decent amounts of troops, supplies, or firepower.
      To be fair, Ive only heard vagueries and generalizations about this subject, so how truly useful the rivers were to the enemy, and what our use of them could have done isnt somthing I can make definitive statements to. But generally Id speculate that having riverine forces that at the least could deny the rivers use by the enemy would be worth the effort.. Hopefully Anon returns with some solid info so we'll all know!!

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    3. "would have almost certainly been used by hostile forces to move fighters and resupply"

      In all the reports I've read, I've never seen any mention of enemy use of waterways. That doesn't mean it didn't happen but, if it did, it's odd that nothing has been reported - or I missed it if it was reported. Let me know if you ever come across any reports.

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  3. Give me an aquatic tank with a decent gun and then we have something small and useful. Even shooting a few widely inaccurate rounds as it approaches the beach would be useful. A small boat, not so much.

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  4. The 40mm Bofors gun on the CV9040 with the gucci ammunition they're using in this vid seems like a much better option.

    https://www.youtube.com/watch?v=YUsgZZeJqhE

    Good for messing stuff up in a variety of ways and is a limited CIWS to boot.

    Also, the Bofors was the basis of the DARDO CIWS and is in use with the Japanese Coast Guard so it should be already/easily marinized.

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    1. If you want to support a light infantry assault moving inland you will want a non-line-of-site system. For all those who forgot the first rule of riverine warfare. "Never get out of the boat."

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    2. "Never get out of the boat."

      I don't know riverine warfare tactics but having a supporting ground force seems mandatory. Without a land force the boat has very limited situational awareness, no scouting, and little idea of what to do as well as being completely susceptible to ambush. The enemy can move freely along both/all sides of the water.

      I can understand that the boat crew, themselves, should stay with the boat but it seems like the must have a land element in order to be effective and survivable.

      Perhaps you'd be willing to enlighten me about elementary riverine tactics and concepts?

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    3. At least in 1971, the riverine manuals were describing a force of Navy watercraft and Army infantry for riverine operations--with potential Air Force assets and coordination with airborne/air assault elements.

      https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/r/riverine-warfare-manual-1971.html

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    4. I wasn't talking about riverine warfare, what I know about that topic could be written on an aspirin with a piece of chalk.

      I've seen some discussion on the inability of 57mm to sink a small vessel, this seems accurate enough to cause some mission killing damage without necessarily sinking the vessel, as well as providing CIWS against targets up to Mach 1.

      I have no idea what you'd want to do with that. But then I have no idea what you'd do with an oversized tinnie in a warzone anyway.

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  5. 1st thought...well, that's interesting.

    2nd thought...what on earth would you use that for?

    Lutefisk

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    1. "what on earth would you use that for?"

      In a peer war ... nothing.

      For peacetime, anti-terror work, modified riverine work. Combined with a ground element (Green Berets, Rangers, Marines), this kind of boat could be quite useful in Africa, S America, the various Pacific island nations, and the like. The ground element provides boots on land, scouting, fire direction, ambushes, etc. and the boat supplies fire support and ?UAV surveillance?.

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  6. "For peacetime, anti-terror work, modified riverine work."

    I agree with the concept completely, I'm just not sure of the method.

    I'm speaking a little from ignorance because I don't know if the mortar is stabilized, but if it isn't it would be quite a danger to the friendlies as well as the enemies.

    A mortar used by infantry troops is set on a heavy base plate pounded into the ground to give a stable platform for accurate shooting.

    If the boat is rocking at all, it's going to change the trajectory of rounds massively. Who knows where those things are going to land.
    (Of course, if it IS stabilized that substantially alleviates that concern.)

    In my mind I'm envisioning something like the Mekong Delta. I guess I'd rather have a Mk19 that can auto-fire 40mm grenades out to 2500 meters in that environment.
    The mortar has a range out to 10k, but the farther out the more that the unstable platform is going to affect accuracy.

    I like the firepower of the 120mm mortar, but I question if this setup really works.

    Lutefisk

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  7. ComNavOps, this is not so much about ground weapons mounted on boats so much in the same vein of the post. I've always wondered why the U.S does not use the same munitions or design different systems (marine and land) for same or similar munitions? Is there a tactical or strategic (or perhaps operational) reason for not STANDARDIZING things as much as possible? I am quite certain logistics will benefit if anything.

    I'll give an example for clarification. Let's say ESSM. That's a good missile although a tad too expensive, but why isn't it being used on land systems? NASAMS exist so clearly someone else thought about it. Wouldn't it streamline production and therefore reduce costs to have at least similar munitions?

    Smaller countries (poorer that is) will greatly benefit from having such systems/munitions.

    - Loc

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  8. I wouldn't call a 120mm Mortar round small. Because of the lower pressures on the shell, its bursting charge is about equivalent to a 155mm Howitzer shell.

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    1. Everything is relative but compared to aerial bombs, missiles, large caliber naval guns, etc., it's small. Four pounds of explosive is not much. As an anti-personnel weapon, it's fine.

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    2. "Because of the lower pressures on the shell"

      I have no idea what that means. Try again.

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    3. As a primarily indirect fire weapon, Mortars are significantly lower velocity weapons, resulting in lower chamber pressures and projectile acceleration, allowing the shells to be built more lightly, with thinner shell walls.
      This allows a greater percentage of the shell weight to be explosives.

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  9. I agree with ComNavOps, this seems like an answer in search of a question. The only use I can think of is gunboat. It could be an inexpensive way of explaining to folks that if they continue to support pirates/sell people/sell drugs without a permit/vote the wrong way (pick one) someone will show up and drop random 120mm Mortar rounds on the village until they see the error of their ways. It may be a good way to maintain the empire, but as soon as a serious enemy shows up someone is going to do an Admiral Fisher and recall the gunboats and put the money into building dreadnaughts.

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