Monday, July 25, 2022

Lessons From The HSV-2 Swift Attack

The former US Navy high speed vessel (HSV) Swift (HSV-2) was returned to the manufacturer, Incat, in July 2013 and then subsequently wound up in UAE service.  The ship was attacked by Houthi rebels off Yemen on 1-Oct-2016.  Reports vary as to what weapon struck the ship with some citing four RPGs and some citing a single C-802 anti-ship cruise missile which seems more likely.

 

Examine the following damage photos and then we’ll discuss them.


 











 

Damage Analysis

 

I am not a combat damage, photo interpretation expert but I’ll offer a few observations about the damage that seem fairly apparent.  The weapon, whatever it was, appears to have struck the starboard bow as evidenced by the inward bent holes.  The port side bow holes seem to mainly be bent outward, suggesting damage from an internal explosion (the missile warhead, presumably). 

 

There is also a large, outwardly bent hole on the underside of the bow, presumably due to the internal explosion of the weapon, which suggests that the weapon did not penetrate to any significant degree before exploding.

 

A large section of the upper bow surface is missing.  Whether that is from the weapon explosion or the subsequent fire, I’m unsure.

 

My novice interpretation is that a weapon struck the starboard bow, resulting in an immediate explosion (contact fuzed?) just inside the bow and producing exit holes downward and to port.  Other photos show the entire forward section engulfed in flames after the attack and fire accounts for the damage to the superstructure and damage aft of the bow.

 

 

Lessons

 

Unmanned Vessels – The Navy is planning on having small, unmanned vessels make up a significant portion of the fleet.  Presumably, these unmanned vessels will be lightly constructed of thin aluminum.  The Navy is unlikely to spend money on thick steel for small unmanned vessels.  The Swift is a good model for an unmanned vessel in terms of combat damage resistance (none) and susceptibility to damaging fire (total).  The obvious conclusion is that lightly built, unmanned vessels will be totally destroyed by single, relatively light hits.  If the vessels are cheap enough, this may be an acceptable situation.  What this tells us is that cost control for small unmanned vessels is paramount as attrition rates will be high.  We cannot afford to allow small vessels to assume large costs, as the Navy is prone to do.

 

Damage Control – Ships will get hit and the ship and crew’s survival depends on damage control.  As history has shown, repeatedly, the number one factor in successful damage control is large numbers of crew.  There’s no getting around it, damage control is physically brutal work and the more live bodies that are available, the better the chance of success.  This also argues strenuously against women on ships.  Women simply haven’t got the physical strength or endurance to conduct effective damage control.

 

Aluminum – Swift’s damage once again demonstrates the foolishness of using aluminum in the construction of WARships.  Recall that the Independence variant of the LCS is all aluminum construction and the Freedom variant has a steel hull with aluminum superstructure.

 

Armor – The damage pattern shown on the Swift indicates that the initial hit occurred at the forward end of the bow (nearly missing!).  The subsequent damage pattern shows that there was no containment or mitigation of the explosive effects.  Armor would have reduced the ‘spread’, extent, and severity of the damage.

 

 

Conclusion

 

The Navy is being presented with multiple, actual, highly relevant, combat damage examples from which to draw lessons (Port Royal, McCain, Fitzgerald, Norwegian Helge, Guardian, Bonhomme Richard, Miami, ex-Swift, Russian Slava class, and others).  Bafflingly, the Navy seems determined to ignore the lessons.  The Navy continues to design ships that are poorly designed for combat and damage resilience and they continue to embrace minimal manning which all but ensures the loss of billion dollar ships to minor damage.

 

Eventually, somehow, some way, we’ve got to embrace the combat damage lessons that are piling up and begging to be applied.  We’ve got to stop designing peacetime cruise ships and start designing WARships.  Unfortunately, the Ford class and the new Constellation do not appear to be WARships and the Navy’s obsession with unmanned vessels certainly does not embrace any combat lessons.

 

Wake up Navy and embrace the combat lessons.


15 comments:

  1. Having actually set foot on Swift over fifteen years ago when she visited the UK, here are some clarifications.

    The weapon appears to have hit the forward end of what was the vehicle deck. There was also a storage space added which I'd suspect contained things that fed the fire. The whole of that deck was essentially open, so blast effects are likely to have been relatively minor. The damage in the photographs is almost entirely the result of internal fire, presumably fed by whatever was in the storage area at the forward end. As we know, once a fire takes hold, aluminium is a "suboptimal" material to be using.

    The ship had no internal subdivision at that deck level, because she was basically a commercial fast ferry. Without subdivision and resilient systems, no amount of crew is going to be able to conduct damage control (particularly firefighting) easily (see Bonne Homme Richard - a warship - for further details).

    On the use of aluminium, note that "thick steel" is not necessarily more expensive than aluminium. For a given structural load requirement, aluminium plate will always be thicker than the equivalent steel - and aluminium welding and sections are not cheap. They are used because they result in a lighter weight structure than steel - which matters if you are a commercial ferry looking for high speed. Or a small high-speed surface "combatant" for that matter. Of course whether that high-speed requirement (and its associated penalties) are valid is a different question, but that's why they did it.

    Armour wouldn't have made a difference in the internal damage spread. The issue there is subdivision, which is a different thing. To keep the weapon out in the first place would have required substantial armouring, which would have had knock-on effects on weight, speed, trim, stability and other structural loads within the hull.

    Bottom line is that she was an experiment, using what was essentially a commercial fast ferry and never expected to be a warship per se. High-speed tends to require compromise - the question is whether that compromise is worth the benefit of the speed. Usually, it isn't.

    ReplyDelete
    Replies
    1. Bingo. The video of the hit is still on line also. https://www.youtube.com/watch?v=58xPnztU4Cc

      Plus you'll notice LCS-2 has anti fire insulation in the mission bay which the commercial ferries don't. I don't expect that to help much, but the ship outside the bay is somewhat more compartmentalized than the commercial ferries. Remember the deck above is also a giant open seating space. Also remmeber, this was an undefended target that wouldn't necessarily even know it was under attack. It was also crewed by foreigners. Perhaps most telling is that it did not sink in spite of all this. All shipbuilding is a series of trade offs.

      Delete
    2. "ferry and never expected to be a warship"

      I trust you understand that this post was not a criticism of the Swift. The intent was to draw general lessons.

      Delete
    3. "Perhaps most telling is that it did not sink in spite of all this."

      It did not. On the other hand, a 320 ft, 1600 ton ship was totally disabled, rendered a flaming wreck, and nearly sunk by a single small missile (or RPGs) that barely clipped the nose of the ship.

      Delete
    4. Indeed. But context is everything. "Thick Steel" vs aluminium for instance. In this case nothing to do with cost. Everything to do with original design and perceived need for speed.

      Delete
  2. I guess I'd rather see the navy experimenting with building Gearing class destroyers with a modern weapons suite, if they have money burning a hole in their pockets, instead of these silly things.

    Lutefisk

    ReplyDelete
  3. The other lesson is to expect the unexpected and to always be on guard.

    The INS Hanit was struck by a Hezbollah C802 antiship missile in 2006 while patrolling in Lebanese waters off the coast of Beirut. In the belief that the ship was not under any threat, a junior officer had turned off the central radar and parts of the ship’s anti-missile defences without notifying the ship's commander.

    ReplyDelete
    Replies
    1. Absolutely correct ! In today's world, terrorists can strike anywhere, at any time. In addition, routine tasks such as sailing have the constant spectre of collision or disaster hanging over them due to poor training and other self-inflicted problems. There is no such thing as a no-threat environment today.

      Delete
  4. You've spoken favorably of the Perry-class frigates before, but weren't those ships made of Aluminium as well?

    ReplyDelete
    Replies
    1. FFG7s had an ally superstructure. As did (memorably) Belknap.

      Delete
    2. A single undesirable feature does not render the entire design worthless.

      My praise for the Perry class has been limited to individual components of the design (missile launcher, for example) or the concept, itself (focused open ocean escort) or in comparison to the LCS (a very low bar !).

      The ship, considered in isolation, was a poor design. It was underarmed, unarmored, decidedly not stealthy, lacked sensors/illuminators, etc.

      Delete
    3. It would seem that the Perry FFG was the LCS of its day, which has received praise with the passing of time.

      I shudder to think that the same might well happen to the LCS, as time goes on! It's quite strange that I can't seem to find many criticisms of the Perrys, which I feel were quite lacking compared to the Spruances or Knoxes.

      Delete
    4. "It would seem that the Perry FFG was the LCS of its day"

      No. The Perry had a well defined mission (open ocean escort) and had a reasonable sensor and weapon fit for that mission. Could it have been better? Of course! But, it wasn't bad. It also had an adequate crew size to handle combat and damage control as witnessed by the Stark and Roberts combat damage incidents.

      The ship also had decent speed, range, and endurance to enable it to execute its mission as opposed to the LCS with no combat endurance whatsoever (return to port every two weeks for maintenance).

      The Perry, with some attendant flaws, was far superior to the LCS.

      "lacking compared to the Spruances"

      The Perry and Spruance were two different types of ship with two different missions. No naval observer would expect them to be comparable.

      Delete
  5. While optimists tend to focus on the fact that the ship was still afloat, this is a much from it being a ASM hit as anything else. Torpedoes explode below the waterline cracking the hull with a higher chance of flooding (and therefore sinking). Heavy caliber gunfire plunges downward at the proper range and heavy bombs which means they can penetrate in the centerline of the ship where munitions etc. are stored which can result in secondary explosions and cutting important support element.
    While effective, the ASM strikes above the waterline on the periphery of the vessel. So the ship's survival less because it was in anyway tough but rather the location of the strike. A mk48 equivalent torpedo would have cracked the hull clean open and sank her. A heavy bomb with a penetrating case would have most probably also sank it. Plunging fire from heavy cannon would have gutted her and possibly set off secondary explosions doing at least as much damage but at a fraction of the financial cost of an ASM.
    I am not saying that anti-ship missiles are weak or ineffective and we shouldn't use them. Just that all weapons have limitations which is why no one weapon or once ship

    On the other hand, if an actual armor belt--not even full armor just an armored belt--were put on that or other vessels, hits from an ASM would be reduced in effectiveness. Not eliminated but the chance of it penetrating deeper into the hull to create secondary explosions would be significantly reduced.

    ReplyDelete
  6. very spot on in terms of the cost, if they want these unmanned vessels in mass, they better be cheap. At first glance these look to be very easy to kill on most models the Navy has theorized. Of course, it's all been theory as to what they would too, which we probably will still be talking theory in 2035 for them. The theoretical sub-hunters they were testing for instance, the Sea Hunter, these need to be cheap enough that you will expect to lose one or two per engagement with a sub, but in a pack that puts certainty that any sub engaged will have 1-2 that successfully are able to launch weaponry that all but ensures a very high probability of a damaged sub. As for manned ships, I find it amazing that the #1 asset, sailors, are protected in mediocre fashion, and the non-physical protection, the EW suite, took 25 years to update and that in the end may be the only real protection even on a Destroyer if they run out of physical protection assets, like SM-2/6 or the CIWS/ESSM run dry. Sure seems the steel won't be protecting them much...

    ReplyDelete

Comments will be moderated for posts older than 7 days in order to reduce spam.