Friday, October 12, 2018

Attack Transport APA

We recently discussed the value of our big deck, amphibious aviation ships and concluded that they did not offer sufficient value to justify their cost.  One of the alternative suggestions was to transfer the aviation capability to the fleet’s regular aircraft carriers and relocate the amphibious ground combat element to dedicated transport vessels similar to the WWII Attack Transports (APA).  Let’s consider the APA in a bit more detail.

The WWII APA, as typified by the Haskell class, was designed to carry 1500 troops and their combat equipment.  The ships carried around two dozen landing craft of various types.  The Haskell APA was 455 ft long and had a displacement of 6900 t (light) and 14,000 t (loaded).  Contrast this to the current Wasp LHD class at 843 ft long and 40,000 t displacement and carrying 1700 troops.  The Wasp is nearly twice as long and three times the displacement with around the same troop transport capacity.


                 Haskell     Wasp

Length, ft           455      843
Displacement, t   14,000   40,000
Troops              1500     1700



Haskell Class APA



The APA contains several inherent design advantages compared to our current LXX amphibious ships.

  • Number of Landing Craft – The APA carried a couple dozen landing craft, the most common of which was the LCVP which carried around 36 troops and had a speed of around 12 kts.  Contrast this with the current AAV which carries around 20 troops and has a speed of around 7 kts.  The LCVP was reusable whereas the AAV is single use but can function as a poor armored personnel carrier on land.  Also contrast the number of landing craft with the 0-3 LCACs that current amphibious ships carry.  A couple of the new America class LHAs don’t even have a well deck and cannot transport and land any equipment that can’t be loaded onto a helo.  The number of landing craft on the APA and their reusability made the APA less vulnerable to the effects of landing craft attrition.  To be fair, the number of landing craft is less an issue of the type of ship and more one of the type of landing craft although the APA’s use of over-the-side landing craft as opposed to the LXX well decks offers certain advantages in terms of numbers.  To be even more fair, if the modern AAVs are considered landing craft then the numbers are more even but there’s no getting around the fact that the AAVs are one use craft as opposed to the LCVPs.

  • Defensive Armament – An APA contained purely defensive anti-air armament (some classes had a 5” gun which was used for anti-air but could provide anti-surface in an emergency).  In a modern context this would equate to simple, self-contained, short range anti-air weapons like CIWS and SeaRAM.  No sophisticated sensor suite would be needed since the weapons contain their own radars.  Contrast this with the sensor suite on an LXX which consists of 2D, 3D, surface search, and air traffic control radars which drives up costs.

  • Cost – APAs were basically commercial cargo ships.  Their austere fit kept the cost down which allowed large numbers of ships to be built.  In WWII, 388 APAs were built – we’re struggling to maintain a 30-ship amphibious fleet.  The low cost and large numbers greatly mitigated the impact of a sunken ship.  As we’ve discussed, the sensor suite, fairly extensive weapons suite, and aviation capability drastically drives up the cost of modern LXX amphibious ships.

  • Commercial Design – APAs were basically commercial cargo ships.  As such it would be possible and quite reasonable to build them for commercial use with conversion in mind and convert them to transports when needed.  Thus, they would serve a useful commercial purpose for the 99% time when we aren’t conducting major amphibious assaults but still be available when needed.

  • Ship To Shore – APAs had the ability to land their entire troop and equipment/cargo load using their organic landing craft.  LXXs are somewhat limited.  In an aviation assault mode, the LXX cannot land most of the Marine’s heavier and most useful equipment.  The lead ships of the America class have no well deck and are limited to only aviation landings which means they can’t land any heavier, useful equipment.
  
So, what does all this tell us?

It tells us that the current big deck LXX amphibious ships are an evolutionary mistake.  They began as an attempt to incorporate aviation, in the form of helos, into amphibious assaults but the concept was carried too far and resulted in hugely expensive ships that have very little use outside their narrow task set of amphibious assault.  The ships are also not very efficient at their main task of actually landing the ground element and their equipment.

We need to give serious consideration to eliminating the big deck LXX amphibious ships, dispersing the aviation element to regular carriers, and using modern APAs to transport and land the ground element.  Along with that, we need to design a reusable landing craft whose only function is ship to shore transport, rather than try to be an all-in-one high speed landing craft / armored personnel carrier / fire support / light tank / whatever else, miracle vehicle.  We keep trying to re-travel the failed EFV path instead of emulating the venerable, cheap, Higgins boat.


The LXX ships are yet another attempt by the Navy to make every ship a single-handed war winner.  Today’s amphibious ships are a combination of fixed wing aircraft carrier, helo carrier, troop transport, cargo vessel, assault ship with, now, rumblings of offensive anti-surface and area anti-air capabilities.  The result is ships that are too expensive to afford in sufficient quantity and too expensive to risk conducting the very task they were designed for – assaults!  You can’t conduct an assault from 25-50+ nm offshore.  We need to return to simple, basic, modified cargo ships as APAs.  

25 comments:

  1. If you just move a land force from point A to point B, you can use the APA with basic lodgings. However, if you deploy for six months, the land force soldiers will need a big gym for enabling them to stay fit, and more comfortable lodging. In the end it depends on deployment vs missions.

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    1. You're correct - and we should not be conducting deployments. This was addressed in the post, Deployments or Missions?

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  2. Served on Charleston LKA 113. During team work 80 we transported a marine battalion and all equipment from Charleston to Norway. Off loaded in the middle of the bay using only our boats. Only took about half a day to unload personnel and equipment. Totally agree with you that we should have this type ship back in fleet.

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    1. Excellent reminder about the LKA's.

      What kind of heavy equipment, if any, did the battalion carry and how did you move it from on board stowage to the landing craft?

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    2. Everything was moved by kingpost cranes up from the cargo holds and loaded onto LCMs alongside. Can't remember exactly but I think we carried 8 boats. Four forward and four aft. Also had a flight deck aft for unreps ect.

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    3. The battalion carried a full load of Jeep's, deuce an half and 5ton trucks and trailers.

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    4. Hey, wasn't the Charleston the one that got hit in Red Storm Rising?

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    5. SRB, do you recall if the battalion carried any tanks, artillery, engineering vehicles, or the like?

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  3. No AFVs. Was a support unit I think. Did have several end loaders and dovers. Lots of pallets with supplies. Largest cranes were rated at 60 tons. Hatch was big enough for M60s or Lavs. Not sure of the cargo deck rating, probably same as the heaviest crane rating. An M1 would a tight fit on that class. Would need a beefer crane also. Not sure if a LCM can carry a Abrahms. Could a M60 though.

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  4. BTW at the time this was a reserve ship. Half the crew we're flown in from around the country just for this 3 month exercise. I was surprised that all departments on the ship functioned like they had been together for some time. Different set of training and leadership back then.

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    1. Great information and story. Thanks for sharing it with us.

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  5. Thanks for the info SRB!

    What would be a modern civilian ship built to 2000s standard that with some modifications could do what the Haskell APA did in the 40s? My guess is there's got to be some kind of modern equivalent? Right?

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  6. The APA concept seems to have some limiting characteristics too. First, putting 1,500 troops in a ship 455 feet long for weeks or months at a time doesn't sound all that appealing. Second, an LHA/LHD provides some logistical support to the landed troops, including medical treatment of the wounded. The APA seems to lack those capabilities. Third, there is no aviation assets for troop deployment, resupply, or medical evacuation. Fourth, an APA seems limited to carrying light vehicles and artillery as opposed to L-class ships that can carry amphibious assault vehicles that provide some protection and firepower, as well as, the mobility to move troops off the beach and further inland.

    I can see an APA-like ship as part of larger amphibious assault group as a way to deploy more troops as part of the initial wave, but not as a complete replacement of an LHA/LHD.


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    1. You've missed the boat (no pun intended) on most points.

      "putting 1,500 troops in a ship 455 feet long for weeks or months at a time"

      You put troops on the ship only for the exact amount of time it takes to sail at top speed to the assault point. You don't do deployments - that's a peacetime thing.

      "medical treatment of the wounded."

      There is nothing to prevent designing in a medical facility on an APA. Alternatively, the Navy operates dedicated hospital ships so those would be the logical source of medical support.

      "no aviation assets for troop deployment, resupply, or medical evacuation."

      That's the entire point of the concept! The aviation element is on a regular carrier and can be employed where/when needed.

      "APA seems limited to carrying light vehicles and artillery"

      As in WWII, an APA can carry whatever you want it to carry. Cargo is craned out of the hold and directly into landing craft. That cargo can be anything.

      "L-class ships that can carry amphibious assault vehicles"

      An APA can carry AAVs, if needed. They can be stacked all over the deck. However, the concept of an APA is to use reusable landing craft. The AAV is a very poor APC. If the Marines need an APC they should procure a proper APC.

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    2. With all due respect, I don't think I'm missing the boat.

      Troop capacity - At 25 knots, it takes 7.5 days from Hawaii to Taiwan and that assumes the good weather and there are no delays. With zig-zagging to avoid submarines, let's say its 10 days sailing time. That's probably doable, but when the mission takes a few weeks or more, that's a long time to be confined in a ship.


      Medical facilities - If the only means back to the ship is via a landing craft, which could take more than an hour even at high speeds (~25 knots), that means the Golden Hour is no more.

      Cranes and cargo - The largest boom on the Haskell class was rated for 35 tons. A WWII LCM was good for 15 tons of payload which is not very good for transporting modern armor. A modern version would need a crane with probably twice that capacity for an LCM-6, which is good for about 40 tons of payload. And, the LCM-8s are probably to big to be efficiently launched by a crane. An APA with a well deck might be something to consider, which would make this ship more like an LSD.

      As an aside, the Marines are buying a wheeled APC (ACV 1.1) with limited amphibious capability and ACV 1.2 is supposed to have the amphibious capability of the current AAAV-7s.


      I think a well deck is more efficient than a crane. With a well deck, the landing craft or AAV/ACVs can be launched en mass as opposed to putting 8-10 boats in the water at a time by crane and then loading them with cargo.

      And, how long would it take to load up 8-10 landing craft by crane? Two to three hours, maybe. Then do that 2 more times to unload the rest of the troops and cargo. I'm not the expert, but that just seems inefficient compared to using a well deck.

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    3. In the first paragraph, I meant to say confined in a ship that small.

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    4. "That's probably doable, but when the mission takes a few weeks or more, that's a long time to be confined in a ship."

      We did this routinely in WWII. Do you see any reason why we can't do so today? It's war, not a vacation cruise. We did it repeatedly so this is a non-issue.

      "Golden Hour is no more."

      There is no Golden Hour in an assault. Do you think there's going to be a line up LCACs waiting on the beach for each individual casualty and immediately race off with one wounded soldier? For starters, there won't be any LCACs (or helos) during the initial assault effort. Once the landing area is secured enough for evac helos and LCACs, we'll establish aid stations on shore so that's where the casualties will go. The worst of those will be stabilized and then transported to a ship. You're laboring under a one-casualty at a time, peacetime misconception. In an opposed assault the casualties will come at a rate of hundreds per minute/hour. There won't be any Golden Hour. That's the brutal reality of real war versus the peacetime stuff we do today and that you've apparently come to believe is war.

      "The largest boom on the Haskell class was rated for 35 tons."

      Because that's all they needed. If we need a bigger crane, we build a bigger crane.

      "A WWII LCM"

      Here's a wild thought - why don't we build a modern LCM with a little better capability?

      "how long would it take to load up 8-10 landing craft by crane?"

      We conducted dozens of assaults in WWII using exactly this method and had no problem. Using modern, stronger, heave compensated cranes we should be able to do much, much better.

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    5. In case you missed it, here's a quote from an earlier comment from someone who served on a more modern APA,

      "Served on Charleston LKA 113. During team work 80 we transported a marine battalion and all equipment from Charleston to Norway. Off loaded in the middle of the bay using only our boats. Only took about half a day to unload personnel and equipment."

      The LKA-113 class carried four LCM(8) on deck. You might want to read up on the class as an example of what a modern APA could be although we can do even more today.

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    6. "With zig-zagging to avoid submarines,"

      Do you think zz'ing is an effective tactic given modern high speed, wire guided,homing torpedoes? ZZ'ing was intended to deny firing solutions but that doesn't seem to be valid today. I truly don't know about this. What do you think?

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    7. "Only took about half a day to unload personnel and equipment."

      That is a long time to unload a battalion and its equipment, but it could probably be done faster in combat. While an APA has more boats and cranes, it also more troops and equipment to offload. By crane, how long would it take deploy almost two battalions worth of troops and equipmemt? Eight hours? Twelve hours?

      It comes down to efficiency and throughput. Which is better, a well deck or cranes?

      A Wasp LHD can carry 3 LCACs or 2 LCUs or 45 AAVs. Given the size of an LCM-8, a Wasp LHD has space for 6 LCM-8s. I'm sure we could load and launch 6 LCMs out of a well deck in a fraction of the time it takes using cranes. Which isn't a lot by itself (~600 troops and equipment), but at the same time an LHD is putting hundreds of more troops and equipment on land by air.

      APAs worked well for their time. But, when it comes to putting the most amount of troops and equipment ashore in the least amount of time, are they applicable in today's combat environment?

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    8. "While an APA has more boats and cranes, it also more troops and equipment to offload. "

      ???? I cited the troop levels in the post and they're essentially the same.

      As far as AAVs, each can carry a theoretical 21 troops. In reality, combat loaded, it can probably carry around 15-18. Wiki lists 15 AAVs per MEU. That's around 225-270 troops and then the AAVs are done since they don't return for more troops. That leaves a thousand troops still on the ship. The MV-22 can carry a similar 15-18 combat loaded troops and an LHD has around 12 MV-22s. Setting aside survivability concerns in an initial assault wave, that's an additional 180-216 troops. That still leaves 800 or so troops on the ship with, now, limited means to get ashore.

      As far as the time required to unload a battalion, there is no need for much of the equipment until the landing area is secured. Dozers, transport trucks, generators, etc. are not initial combat items. So, the battalion does not need to unload instantaneously. Only the immediate combat portion needs to land quickly.

      "I'm sure we could load and launch 6 LCMs out of a well deck in a fraction of the time it takes using cranes. "

      Depends on what you're talking about loading. Troops can board a WWII Higgins boat just as fast over the side of the ship as through a well deck. Heavy equipment can probably load somewhat faster through a well deck but that type of equipment is not needed on a "speed" basis, as discussed above.

      "when it comes to putting the most amount of troops and equipment ashore in the least amount of time"

      That's not the goal of an assault. The goal is to put the right type and right amount of troops and equipment ashore when needed - not as fast as possible. In fact, piling up too much troops and equipment on an unprepared beach is detrimental. Recall that it took quite a while for the beaches at Normandy to be secured and readied for high volume throughput of men and materiel. For the first day the troops were often pinned down and additional piling up of troops and equipment would have just resulted in additional losses.

      Finally, bear in mind that the point is not whether a LXX is capable of conducting an assault - it is - but whether the capabilities it offers is worth the cost at a few billion dollars apiece. The APA offers essentially that same capability if the aviation element is off loaded to carriers and does so at a fraction of the cost.

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  7. IMO The most versatile Amphibious type in the fleet are the LHD's. They perform all the roles as well, I'd sooner stop productions of all other amphibious types for more LHD's. You can most of a MEU on one, a squadron of F-35's, or even a small boat squadron for brown water ops.

    The loss of supplies and lighter-age with forgoing LSD's and LPD's seems to be irrelevant to modern operations. When was the last time a MEU was landed in hostile terrain, and only supported by the ESG ships and their stores? Never; in fact they typically split up into single ship elements anyway. If its big enough for a 30-45 day op, then a larger element than a MEU is in use and/or available.

    Indeed I think the LHD's are the perfect centerpiece for the colonial patrol type fleet. Keep these ships patroling, and forward deployed. Keep the battle fleet in port or during training sorties until needed. Tie a single DDG for them for firepower.

    For a MTW invasion, the amphibious fleet will need large numbers of LST, LASH, LO/LO, and all manner of ships typically found on the reserve rolls anyway.

    Pretending we will gather the entirety of the current gater-navy to land Brigade(s)of Marines by Amtrac's is fantasy. Accept we use them for police actions forward deployed. Use them as that, and otherwise cut and streamline those obsolete hull designs.

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    1. The problem I have with your concept is that a $4B+ ship is awfully expensive to apply 1/3 of a MEU to a very low end scenario (1/3 of a MEU simply can't handle anything other than a very low end threat).

      If a third of a MEU is the type of peacetime force we want to apply, can you envision a cheaper way to accomplish that then by maintaining a 30+ amphib ship fleet of multi-billion dollar ships?

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    2. I agree 100%. The LHD is ideal for peacetime roles, and is all a MEU needs. Current three-ship MEUs are too big for peacetime ops and far too small for real combat ops. Stop building the planned LXs to replace the LSDs and keep the other ships at home and gradually replace them with true amphibs (LSTs)

      On the other hand, once an real war threatens, the LHDs become light carriers and offload the Marine troops. It can operate a squadron of F-35Bs IN SUPPORT of a Carrier Strike group, or maybe embark Navy helos for ASW hunting or escort roles.

      People write that our Navy needs some light carriers. IT ALREADY HAS A DOZEN! If war breaks out with China only a fool would sail an LHD around with and embarked MEU. Plan and train for the instant conversion of all LHD to CVLs. Once with sea war is won, we can think about amphib ops.

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    3. Allow me to add to my post based on MEU experience. Of course the MEU would need to be smaller. It can leave the artillery battery behind since it rarely has been needed, and one can be sent from MPS within a week with Marines airlifted when rarely needed.

      The six F-35s are just eye candy. They are nothing in a serious fight, which would include a carrier group anyway. Leave them off the ships, BUT deploy an entire squadron UDP to an airbase in the region for that instant CVL conversion option. Finally one infantry company can deploy by air to a regional airbase along with the two C-130s that now deploy for each MEU in direct support.

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