Friday, August 14, 2015

LSM(R) Fire Support Ship

History is the greatest source of lessons for the student of modern combat.  To that end, let’s see what history can tell us in today’s post.

WWII saw the evolution of amphibious assault culminate in the Pacific island invasions late in the war.  By the end of the war, the equipment and tactics had been as nearly perfected as possible.  Ironically, most of those hard won lessons have since been abandoned and forgotten.

One of the needs that was identified was for the ability to provide a massive pulse of explosives just ahead of the assault waves.  One of the ways this was accomplished was by the LSM(R) which was a specialized version of the Landing Ship Medium which mounted rocket launchers as well as 5” guns and mortars.

A typical, early LSM(R) was the -188 class,

LSM(R)-188 class , 200 ft, 1100 tons
5” gun
75 x 4-rail Mk36 rocket launchers
60 x 6-rail Mk30 rocket launchers

Further development of the LSM(R) culminated in the -501 class

LSM(R)-501 class , 203 ft, 1200 tons
5” gun
20 x Mk102 twin tube continuous loading 5" spin stabilizer rocket launchers
4 x 4.2” mortars


The Mk102 rocket launcher was an amazing weapon.  It was a twin tube, continuous fire launcher with train and elevation.  It was capable of a sustained rate of fire of 32 rockets per minute.  The latter LSM(R)s mounted 10 or 20 of these launchers – that’s 320 to 640 5” rockets per minute.

The rockets fell into three broad categories,

Mk7 5” Spin Stabilized Rocket, 10,000 yds, 2.8 lbs TNT
Mk10 5” Spin Stabilized Rocket, 5,000 yds, 9.6 lbs TNT
Mk12 5” Spin Stabilized Rocket, 2,500 yds, 12.0 lbs TNT

Mk 102 Rocket Launcher

A single LSM(R) could deliver amazing amounts of firepower and several ships operating together provided absolutely incredible amounts.  Of course, the LSM(R)s were only a part of the naval fire support.  Dozens of battleships, cruisers, destroyers and other specialized fire support ships also contributed to the massive delivery of explosives to the assault site.  Contrast that to today’s few ships armed with only 5” guns and relegated to operating beyond the gun’s range.  Tomahawk missiles are available but those are not really intended for area bombardment due to their expense and very limited quantity.  We have abandoned fire support for amphibious assaults which calls into question the viability of assault doctrine in general.

The LSM(R) provided a small, cheap vessel that could get in close to an assault site and deliver massive amounts of cheap firepower.  The proximity to the beach assumed a high degree of risk but the small size and cheapness of the vessels made the risk acceptable.  Today, we have $2B Burkes with a single 5” gun that are constrained by doctrine to remain so far from the assault site that their gun can’t even reach the beach!  Even if we wanted to place a Burke in close, who would seriously consider risking a $2B ship playing tag with shore based artillery and missiles.  Our ships have become too expensive to risk doing the very jobs they were built for!

So, is there a need for a modern LSM(R)?  If we’re seriously contemplating amphibious assaults, there is.  Current doctrine does not call for tanks and artillery in the initial landings (another lesson forgotten).  With no naval gun support and few aircraft (probably exclusively tied up defending the fleet), the Marines will have no heavy explosive firepower until they can get their own artillery and tanks ashore.  Of course, remember that the Marines are cutting tanks and artillery in their quest to get “light” so there’s not much coming ashore even if they could get it ashore.

Against a peer defender, trying to come ashore with only infantry and AAVs with 0.50 cal machine guns is a recipe for disaster.  A modern LSM(R) could help address the initial firepower gap.  Sadly, we have become so enamored with precision application of firepower that we have allowed our total firepower delivery capability to nearly vanish.  There is still a significant place for suppressive fires during the initial landing. 

History is talking to us but we’re not listening.


  1. This comment has been removed by the author.

    1. Good link. Thanks! It's interesting that the general thrust of the comments was to increase the concept: more weapons, more AAW, more speed/range/size/dinner plates/whatever. The LSM(R) was a cheap vessel. It had no AAW beyond what we would call point defense. People consistently miss the point about single purpose platforms: they don't fight alone. The LSM(R)/cheap arsenal ship would only be fighting during an assault and, by definition, would be surrounded by other ships that would provide AAW, ASW, ASuw.

      The other common attempt in the thread was to want to turn the ship into a multi-role vessel which, again, misses the point. An LSM(R) would have only a single purpose: to support an assault. During peacetime it can sit tied up to a dock doing nothing other than training. For all the peacetime tasks we should build a small fleet of very cheap, very small vessels (Coast Guard cutter-ish) to go show the flag, fight pirates on skiffs, conduct officer exchanges, train with other navies whose biggest ship is a rowboat, and all the other nearly useless stuff we do.

      Still, the MLRS is right up the alley of the LSM(R). I would not call such a ship an LSM(R) or cheap arsenal ship, I would call it an amphibious assault support ship since that is it's one and only purpose.

      What I like about the cheap arsenal ship and the LSM(R) is that they recognize the need for area firepower as opposed to the idiotic obsession we have with precision. Yes, there's a place for precisions (a big and useful place!) but, come war, we're going to find out that there is a need for are firepower.

      Aside, I see what I assume is you with "VA" in your username. Is that a reference to Vet Admin or Virginia?

    2. This comment has been removed by the author.

    3. It's estimated that it required 1,452,017,639 rockets to kill one enemy soldier. I wonder why they used them, being that ineffective?

      A ship like this that would sit pierside does not need a crew. A shore based caretaker crew is all that's needed. When the ship is needed it can be crewed from the manpower pool. It's function doesn't require any great degree of skill. The aiming will be just a software function.

      You've bought into modular with absolutely no evidence that it is a useful concept for the USN. The LCS has proven to be a complete bust regarding modular use. Even the Navy has admitted this.

      A modular ship in continual use is continually wearing out. A non-modular ship sitting pierside is not. We can buy them and keep them for 50+ years.

    4. "Blowing up dirt isn't terribly useful."

      The LSM(R) was used for two purposes:

      1. Suppressive fire as the assault waves were landing.
      2. Area fire to hopefully kill and destroy enemy personnel and assets that were not specifically seen and targeted. If you blanket an area with hidden targets, you're bound to hit some of them. Given the extreme difficulty in locating targets, area bombardment is not only viable but desirable.

    5. This comment has been removed by the author.

    6. Smitty.... Why not just build a ship that works, and does what you need it to do... Its a bit strange to send a ship out and say 'today this ship doesn't need ASuW capabilities, today this ship is only going to need basic point defense.... etc..etc.'

    7. Smitty, if we're talking about the low end ships like this LSM(R), built to nearly commercial standards, we should be able to get them for around $50M (a large commercial tanker costs $100M and we want something half that size or less). Comparing that cost to an LCS at $500M, we can have 10 LSM(R) for the cost of a single modular ship. If we consider the LSM(R) to have a 50 year lifespan, we can build 20 LSM(R) for the cost of one LCS over a 50 year lifespan (assuming an LCS will last 25 yrs). So, we can meet an entire major amphibious assault force's needs for the cost of a single modular ship.

      Of course, if the assault never happens we've wasted our money but the same can be said about many weapons and systems. We buy to be prepared, not necessarily to use.

      I can't see the modular concept being practical for the USN. For one thing, we have so few of everything (relative to our stated needs) that whatever the first module installed is, it will become permanent. Consider a modular "cargo" vessel (where cargo means the module and whatever is needed to make the module work), also built to nearly commercial standards, hence cheap. If we give it a MCM module, it will never be removed because we have so few MCM assets. The same holds for whatever other modularized function you wish.

      Further, most modules require an extensively trained crew. You can't just conjure them out of thin air. If we place our MCM module on our cargo vessel, we have to extensively train them. MCM, as you know, is a difficult skill and easily perishable (one of our current problems). If a year later we want to switch the ship to ASW, what do we do with the MCM-specific crew? And a year or two after that when we suddenly need MCM, where do we find exquisitely trained MCM crews just sitting around waiting to board our cargo vessel?

      Modular sounds fine on paper but has no practical utility that I can see. For low end, non-skilled functions like HA/DR a modular vessel could work, perhaps but I'd treat HA/DR, in particular, like pre-positioning - have fully loaded HA/DR ships pre-positioned in likely areas with standby civilian crews. So, again, I'm back to not seeing a practical use for modular in the USN.

      With all that said, I can see a value in a base "cargo" vessel that is designed and built in a modular fashion so that during construction we insert the desired module into reserved spaces and thus the function of the ship is determined (MEKOs are built this way).

    8. CNO,
      If you are going to build such a ship [the LSM(R) concept], why not just keep the ship in service for 25 years and then sell it for ~$30-40 million.
      It'd still have 25 years of life left in it (more like full 50 if it just sat in port) and was pretty much just a Heavy Duty Cargo ship anyway, just with MLRS or Heavy Artillery units parked on its deck, so there would not be much cost to demilitarize the ship and turn it over.

      From a civilian business side, you could actually get a fleet of these going for less than the cost of operating the same volume of larger ships, so there are benefits to this for them as well.
      (on top of any possible maintenance, crew, fuel, etc benefits)

      But on the topic of the ship itself, it could also serve as a general purpose transport ship (which is something I find that we are comically lacking) - meaning that it would actually have purpose in peacetime.

    9. Ray, the base LSM wasn't all that big. It was around 200 ft in length and could carry half a dozen vehicles or tanks and 50 or so troops, maybe more. I'm not sure how much general cargo it could carry and whether it would be enough to justify serving as a general purpose transport. What do you think?

    10. CNO,
      I think 'good point'.

      I had failed to consider the previous ships and mostly made my considerations based on a ship hull about 2/3 the size of the commercial tankers, since you had mentioned 'built to nearly commercial standards'.
      (I've not priced tankers and cargo ships, but tankers seem more complicated than cargo ships to me, so I assume that cargo ships are cheaper.)

      Thus I ended up with a vehicle cargo ship a similar to a fatter US T2 Tanker from WW2 (if one can wrap their head around that image) at just over 500ft length.
      You may be able to see where I got the general cargo space from.

  2. Nice video of one in action off Vietnam

  3. Rocket artillery is seldom accurate (unless you want really expensive munitions) and it's main values are:

    1. Suppression (forces the enemy to go into cover)
    2. Psychological (makes the enemy panic, which can be huge)
    3. If anything is left in the open, the sheer volume of fire can often destroy or heavily damage it (near misses), unless it's very heavily armored (in which case it can be out-maneuvered by ground forces)

    You can have more accurate weapons like the MLRS, but they are much more expensive and as a result, you cannot have the kind of volume.

    1. Accurate rockets (missiles) are expensive because we insist upon gold plate!

      Unguided 70mm air-to-ground rockets have been effectively converted to guided missiles for ~5K a pop, we are not talking about trying to lob these through a specific window pane at 300 nm, we just need enough trajectory shaping to be get a consistent sheath(s).


  4. CNO,

    To make this concept work in the 21st century I would use an commercial ocean going articulated tug barge (ATB) concept (tug pushes the barge)

    The barge providing the basis for the ordinance, and could be left pier side until needed. ATBs are slow, but dirt cheap - transport to the area of operations could be done via semisubmersible lift ships ranging from yacht transports up to massive heavy lift ships.

    To keep these cheap I would go directly with land based rocket and 155mm tube artillery, although I would re-barrel the old guns to take the latest high pressure NATO gun-howitzers with larger chamber volumes.

    For the rockets, The mission is neutralization fire. I would concentrate on 110mm,122mm or 160mm systems. the LAR 160 with a 45km+ range and rather heavy warhead. Guidance (GPS, laser, etc.) can be added for ~$5K per weapon, but we might want to limit the cost and use simple trajectory shaping technology. The principle warhead should be a modern cluster munition (with a dud rate of less than 1%) , thermobaric, and a multispectral smoke/HE-fragmentation.

    I would store the barges on land or in fresh water (GLAKES - Mississippi - etc.), in wartime these things have a life expectancy of a couple of years. The point is to keep it cheap, and effective!



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