Monday, September 15, 2014

Sea Basing

What the heck is sea basing?  Ten different people will give you ten different answers depending on their particular agendas.  Is it a means of providing direct fires ashore?  Is it the stepping off point for an amphibious assault?  Is it an aviation-centric floating base?  Is it a transfer point for movement of materials from one ship to another?  Something else?  All of the above?

Of late, the term sea basing has come to be associated with amphibious assault, particularly as a means to transfer material from larger cargo ships to smaller ships or connectors for subsequent movement to the beach.  OK, fair enough.  That’s the flavor of sea base that we’ll confine this discussion to.

Before I go any further, let me relate a brief, totally unrelated anecdote.  The other day I was returning from a trip to the grocery store.  I exited the store, hopped in my car, and drove to within about a mile of my house at which point I stopped, got out, and transferred the groceries to another car.  I then drove that car to my driveway at which point I stopped and transferred a few of the grocery bags to a small cart which I then pulled up to the house.  As I was doing so, I couldn’t help but reflect on the incredible inefficiency of the whole process.      That’s it.  End of story.  OK, possibly the anecdote wasn’t totally unrelated.  I take it you see the analogy?

The inefficiency of using a sea base to transfer cargo from one ship to another, just miles away from the ultimate destination is striking.  Constructing an actual platform, be it a Mobile Landing Platform (MLP), Afloat Forward Staging Base (AFSB), a simple barge, or whatever, is an expensive inefficiency in the process of moving equipment and supplies to their destination.  It’s also an incredible inefficiency in terms of the time and effort required to unload a previously loaded large ship just to reload the items onto a smaller vessel so that they can be unloaded yet again a few miles further on.

Are we sure that designing ships that can unload directly over the beach wouldn’t be a better way to go?  We had such a vessel, the LST, and opted to retire them with no replacement.  Was that really a wise move?  But, I digress ….

What’s that, you say?  What sea state can this sea base material transfer operation take place in?  Good question.  I don’t know but I suspect not much.

The Sea Base is not only expensive, inefficient, and time consuming in use, but it offers the enemy an incredibly lucrative target.  We aren’t planning on having many platforms that can fill this function so destroying a couple of them can halt an assault in its tracks.  In this age of aircraft and missiles with ranges of hundreds or thousands of miles, the Sea Base will always be within range of enemy weapons.  Of course, there’s always submarines – an SSK assigned to take out our Sea Base is a highly effective tactic and very difficult to prevent.  I’m sure we’ll provide protection but the enemy only needs one aircraft, missile, or torpedo to get through and they’ll undoubtedly devote some pretty substantial efforts to that end.

A Sea Base is one of those ideas that probably makes an impressive PowerPoint presentation but suffers a bit in the real world.

On a related note, there are other types of sea base operational concepts that may make sense such as basing for an offshore Army aviation unit but those are topics for another time.

I can’t help but think that the time and money spent on developing the sea base concept would be better spent on designing and building cargo/transport ships that can unload directly over beaches and/or in far more shallow water ports than currently accessible.  Perhaps something along the lines of a RO/RO LST is what we need?

The Sea Base should be a candidate for base closure in the next round of cuts!


  1. The problem is capacity. The Newport-class LSTs had 1,700 m2 of vehicle stowage. A single Bob Hope-class LMSR has 35,000 m2. You need over twenty Newports to equal one Bob Hope.

    IIRC, the LMSRs cost around $400-500 million each. It's doubtful a new LST would cost much less than that.

    The MLP is designed to permit offloading of these huge cargo ships without needing port facilities. It's meant to enable follow-on forces in a relatively benign environment.

    Plus, if you think an MLP sitting over the horizon is vulnerable, think about a bunch of beached LSTs.

    1. Why not focus on a portable/floating dock system that allows the LMSR to deliver to an non port beach? Seems to me we could figure out how to have cheap floating barges that go out to the LMSR and allow their RO/ROs to come right off.

    2. We do have such a system. It's called INLS (Improved Navy Lighterage System). It doesn't have the (theoretical) throughput of the MLP/LCAC/LMSR system and can't handle sea states as high.

    3. B.Smitty, are you objectively considering the flip side of capacity which is survivability? A few, large ships represent a very vulnerable, attractive, and high rewarding target. Numerous smaller vessels such as an LST represent a more distributed, overall safer means of ensuring that a significant portion of the load makes it to shore.

      If an enemy can hit the one (or few) MLPs/AFSBs or whatever we're using as the sea base transfer point, the entire assault is finished.

    4. How far out, from the beach, can the INLS go to provide a drivable dock from the RO/RO? The Defense Industry Daily webpage says it is fine up to Sea State 3.

      Seems to me that defending this is alot like the issue of bridging rivers. They provide high value targets with aertillery usually very close, but the Engineers get it done. Why is using INLS any different?

    5. CNO,

      Yes, fewer, larger targets is a result of the current LMSR/MLP approach.

      Survivability is a complex equation.

      LSTs are subjected to many threats that shouldn't bother the MLP/LMSR, such as shore and near shore mines, artillery, mortars, ATGMs and other direct fire systems. LSTs also have to transit deeper water zones, infested by SSKs and midget submarines, on the way to and from the beach.

      Also, LSTs have a much more limited set of beaches they can access. That reduces the number of places an enemy has to defend.

      There are pros and cons to each approach.

      We have to remember, though, that these large cargo ships are often MPF ships, prepositioned with BCT or Marine Brigade sets around the world. This prepositioning greatly speeds the closure time of follow-on forces. Unless we were willing to buy, load and park MANY LSTs, we wouldn't have the same follow-on capacity.

      Another option is to build somewhat smaller cargo ships. LMSRs provide greater square feet per dollar, and lower life cycles, but they are large, attractive targets. They are also limited in what ports they can use.

      If, instead, we were to buy more numerous, but smaller, MPF ships, they would be able to use many more "small" ports around the world.

    6. CNO,

      Without MLP, all of our existing, large, MPS, sealift and RRF ships are restricted to offloading at deep water ports or waiting for INLS or ELCAS construction and operation. INLS doesn't support the full range of offload activities (e.g. breaking down containers into pallets).

      We have a lot of these ships, and without something like MLP, we are hamstrung in our ability to deliver bulk follow-on forces and cargo.

      Here's an older NPS thesis that models some Sea Base activities. It assumes a more robust MLP than we're getting, but it does highlight some of the need.

    7. B.Smitty: "Without MLP ..."

      I know. That's what I said in the post. I then went on to describe why that's bad and what we should do instead.

      You seem to support the sea base concept over direct unloading at the beach/port. OK. Why? What advantage do you see in sea basing that more than offsets the inherent inefficiency and vulnerability?

    8. The MSC currently has 50+ odd RO/RO and container ships, split between the MPS and sealift fleets. The MPS ships already have prepositioned Marine and Army Brigade sets on them and are at strategic locations around the world. The RRF has another 40+ cargo ships of various types.

      This aggregate capacity dwarfs the entire amphibous fleet by MANY times. It takes just one LMSR to deliver an entire SBCT brigade set. It takes just one and a half LMSRs to deliver an entire HBCT brigade set.

      This capacity is how we move the bulk of our land force combat power around the world. Our entire airlift and amphibious lift capacities are bit players, in comparison.

      These 50-90 MSC ships are large and require large ports. If we don't have a large port in theater, the vast bulk of our land combat power has to sit on the sidelines, use slower methods like INLS to offload, or wait for an ELCAS to be built (which take a week or more, if even possible).

      The Sea Base concept was designed to address this issue.

      Buying LSTs won't address this problem. They can't enable the vast MSC fleet in a port-denied situation.

      And we can't afford anywhere close to enough LSTs to directly replace this MSC capacity. For example, we would need FOUR HUNDRED LSTs to replace the lane meters on just the twenty MSC LMSRs.

      Clearly that is un-affordable.

    9. B.Smitty, you don't see that as an incredible vulnerability? You recall a previous post in which I mentioned that hitting those ships would make for a fantasic Pearl Harbor scenario for China?

      You don't see the MLP/Sea Base as an even more incredible vulnerability? Destroy the MLP and the assault is over.

      We certainly can afford any number of LSTs. It's just a matter of prioritizing our spending.

      You have to wonder how we mananged to move divisions and armies in WWII without these 90 giant ships and how we managed to get all the men and gear ashore in invasion after invasion. That almost suggests that it can be done without sea bases.

      I seem to recall you arguing for distributed firepower in the green water discussion and here you're arguing for highly concentrated capacity. Hmmm ........

    10. All of the MSC ships I mentioned are ships we already own (or have on long-term leases). Many already have Marine and Army equipment sets on them. They have decades of useful service life in them. MSC ships can often last 50 years, given their low usage rate. They are about as cheap per ton-mile delivered as you can get.

      The MLP adds a capability to enable these existing assets in a new way. Are there limits? Sure. They aren't to be used for amphibious assaults. They are for follow on forces and sustainment. The original Sea Base concept has been scaled down due to rising costs. Still, I think if it works as advertised, the MLPs are a valuable addition.

      In WWII we took ports or made ports (Mulberry's until we took Cherbourg & Le Havre), or the initial invasion fleet was sufficient by itself (island hopping in the Pacific). Our economy was also on a war footing so we could afford to buy the many ships needed.

      Note, the bulk of US material used to support the Normandy invasion and the push through Europe was carried across the Atlantic and English Channel on bulk cargo ships, not amphibious ships.

      Unless you can convince Congress to dramatically increase the SCN budget, buying LSTs means not buying something else.

    11. B.Smitty, if I understand the thrust of your comments, you believe the sea base concept is the ultimate, perfect solution to our assault needs and requirements. At worst, you grudingly acknowledge a few minor faults but believe that sea basing is the best solution possible given the budget we have to work with. Is that a fair assessment of your position?

      If so, I can only imagine the unrestrained joy among enemy commands who look at our assault capabilities and note that damaging or destroying a couple of MLPs would totally abort any invasion attempt.

      Once again, shockingly, we'll have to agree to disagree!

    12. Let's dispense with the term "sea base". It means different things to different people (as you rightly point out).

      Let's talk specifically about the MLP.

      The MLP is NOT an amphibious assault platform. It is a sustainment and follow-on force enabler. By the time the MLP sets up shop, the assault has happened and the lodgment is secure (relatively speaking). In theory, that also means the MLP's operating area is relatively secure as well.

      Ideally, we have a friendly, deep water port where we can offload cargo and follow-on forces (think Desert Storm). This is, by far, the fastest way to build up land combat power. In this case, we don't need the MLP.

      Short of that, in situations where our amphibious assault force are insufficient to achieve the objectives, we need ways to move follow-on land combat power from our bases to the theater of operations. Traditionally that has been through MSC shipping (and, to a lesser extent, airlift).

      The Navy is adding the JHSV to the mix as an in-theater shuttle. So for operations where we do have a friendly port nearby, the assault echelon can "just" take an austere forward port and we can shuttle forces from the large port to the small one.

      The MLP opens up the possibility of bringing follow-on forces and cargo ashore directly in situations where we don't have any port access, and where we haven't set up an ELCAS or other JLOTS solution.

      Again, this is not part of the amphibious assault phase! This is post assault, building up forces ashore.

      Personally, i would like to see the MSC buy some number of smaller cargo vessels. Something larger than a JHSV, with greater capacity, range, and seakeeping, but smaller than an LMSR, with greater port accessibility. Remember, the fastest way to bring combat power ashore is to use an existing port.

      From this Port Accessibility Study,

      A ship with the following particulars could access 66-70% of the small ports surveyed:

      Length: <600ft , Beam: <100ft, Draft: <25ft

      So a ship like the British Point class Ro-Ro would be in the ballpark.

      In contrast, an LMSR would be able to access less than 33% of the ports surveyed.

    13. B.Smitty, sea base was the point of the post so it's a little hard to dispense with the term! I'm using the term in its current, most common usage.

      Few people, the Navy included, seem to make the distinction you do between assault and sustainment.

      I continue to offer the observation that a few MLPs offer an incredibly lucrative target for the enemy and that distributed transport in the form of RO/RO-LSTs are a far safer and more versatile approach.

    14. The Navy does distinguish between assault and sustainment, but the "Sea Base" term has been used for any potential use of offshore basing.

      The MPF/MLP combo can't perform assault because troops still have to be married to their gear ashore!

      LSTs were called "Large Stationary Targets" back in the day. I think you're trading one vulnerability for another.

      Their designs are just hamstrung by the fact that they have to beach. They can't be very large or carry very much. Up until the Newports, they were also rather slow.

      Given all of that, and their beach gradient restrictions, I just don't see them as a good buy for us.

      IMHO, an austere LPD like the Enforcer or Endurance classes makes more sense. They can still sit a ways offshore and use lighterage to offload. Dispensing with the requirement to beach greatly simplifies their design.

      And we don't need LCACs/SSCs everywhere either. There are plenty of off-the-shelf lighterage systems that are far cheaper (e.g. L-CAT, LCM-1e). Sure, in a one-to-one comparison, they may not have the throughput of the LCAC, but they are far cheaper to buy and operate.

  2. CNO,

    A more apt analogy is as follows:

    You want to buy a TV. You drive to your local warehouse store and pick one up. However the warehouse didn't build the TV. It came from overseas via a large container ship.

    Your car is the lighterage that takes the TV the last mile(s). The container ship is the LMSR bringing huge quantities of equipment across the sea from the factory or storage location. The warehouse is the LMSR/MLP combo, where selective offload from the LMSR meets the "show room" of the MLP.

    1. B.Smitty, to use your analogy, how many loads, unloads, reloads did the TV undergo to get from the ship to my store? Several, undoubtedly. Inefficient, to say the least! The most efficient process would have the cargo ship pull up next to my home. We're mixing land and sea movements so the analogy falls apart but it illustrates the issue.

      You may disagree with my conclusion about sea basing but the fundamental inefficiency of loading, unloading, and reloading is factual and inherent. The question is whether the inefficiency becomes the lesser of evils when the other factors such as survivabililty are considered.

  3. The Defense Science Board did a pretty thorough study on sea-basing in 2003 that is still pretty valid since the Navy hasn't really followed most of their recommendations. I think you would find it very informative.

    Randall Rapp

    1. Randall, I've read it. It contains a number of fundamental logic flaws that invalidate or, at best, negate the supposed advantages.

      The main flaw is that it requires extensive combat support to ensure its protection. If that degree of support is available then it would be just as safe to land the material directly ashore via RO/RO-LSTs rather than go through the exercise of unloading/reloading.

      The secondary flaw is that it is self-limiting to only light combat operations. There is no mechanism proposed for getting tanks and other heavy equipment ashore.

      While not a logic flaw, the document emphasizes that their concept is a FUTURE concept and will require the development of new ships, connectors, helos, etc. I suggest that given the preceding logic flaws the money and effort would be better spent on designing new RO/RO-LSTs.

      I can go on but you get the idea.

      Was there a particular aspect you wanted to draw my attention to?


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