Wednesday, April 22, 2020

VLS Versus Arm Launchers

Our recent discussion about the Virginia class cruisers (see, "Virginia Class Cruisers") brought up the issue of ‘arm’ launchers versus vertical launchers (VLS).  As you know, it is accepted as an article of faith, today, that VLS systems are vastly superior to the older ‘arm’ launchers such as the Perry’s Mk13 single arm launcher or the more capable Mk26 twin arm launcher.  Is this really the case?  Let’s look a bit closer.

The end development of the arm launchers was the Ticonderoga class’ Mk26 twin arm launcher so let’s look at the advantages and disadvantages of both the Mk26 arm launchers and the Mk41 VLS.

Arm Advantages

Pointing.  The arm launcher points directly at the target and the missile launches horizontally rather than vertically.  This means there is no delay while the missile tips over and acquires the target.  Therefore, the missile gets to the target faster than it would from a vertical launch system.

Magazine Protection.  Because the missiles are stored below deck, presumably in an armored magazine, the missiles are better protected.

Deck Space.  An arm launcher requires very little deck space as opposed to a VLS which is spread out over a large deck area.

Arm Disadvantages

Single Point of Failure.  An arm launcher represents a single point of failure.  If the launcher is rendered non-functional for any reason, the entire missile capability is unusable.  Obviously, with two launchers, the remaining launcher could continue to function.

Firing Arc.  Arm launchers have a limited firing arc because the ship’s superstructure masks portions of the firing arc.  Assuming the ship has time to maneuver to unmask its launchers, which would almost always be the case, this is not a serious drawback but it is still a limitation.

VLS Advantages

Missile Availability.  In a VLS system all of the missiles are immediately available for use.

Maintenance.  Missiles are supplied as sealed canisters which minimizes maintenance.

Simplicity.  A VLS system is mechanically simpler and more reliable.

Missile Size.  A VLS is capable of launching larger missiles such as Tomahawks.  The Mk41, for example, was supplied in three sizes to accommodate different missile sizes although, currently, only two sizes are offered.  To be fair, this advantage comes at the cost of more internal ship’s volume being consumed which is a disadvantage.

VLS Disadvantages

Tip Over.  The vertical launch requires that the missile travel straight up (90 deg off the target vector) after launch and then tip over to the horizontal and acquire the target.  This delay means that it takes longer to get to the target.  This delay could prove critical when using ESSM at shorter ranges or against supersonic missiles when every second counts in terms of the number of engagement attempts possible.

Exposure.  The entire missile inventory is exposed at deck level and is unarmored from above which renders the ship’s entire missile inventory more susceptible to battle damage.

Launch Failure.  Vertical launch systems are susceptible to damage from a failed launch due to either a restrained (obstructed) launch or fallback if the missile engine fails/explodes during launch.  This exact scenario happened to the US Burke class destroyer The Sullivans, just recently, and to the German ship Sachsen a couple years ago.  Both ships were damaged and set afire.  In contrast, a failed launch from an arm launcher results in the missile being ejected over the side of the ship rather than falling back on the ship.  Any initial motor explosion would occur off the side of the ship and debris/fire would not fall back on the ship.


Firing rate.  It is a common belief that the VLS has a much faster firing rate than an arm launcher.  However, the useful, effective firing rate for arm launchers pretty well matches the VLS.  The Mk26 twin arm launcher could launch two missiles every 9 seconds.  For ships such as the early Ticonderogas and the Virginia class cruisers, both of which mounted two launchers, one fore and one aft, that equates to 4 missiles every 9 seconds or a missile every 2.25 seconds.  Given the Navy’s typical shoot-shoot-look engagement sequence, a missile every 2.25 seconds is adequate for nearly any scenario.  Today’s VLS really offers little in the way of an effective enhanced firing rate. 

Illustrative Examples

The Perry class frigates had a Mk13 single arm launcher with a 40 missile magazine.  By comparison, we’re struggling with today’s frigate designs to get 32 VLS cells to fit into a design.  The US Navy’s new frigate design, for example, is spec’ed at 32 VLS cells, a 20% decrease in capacity from the Perry class!

As noted, the Virginias and early Ticonderogas had 2x rapid fire Mk 26 twin arm missile launchers mounted fore and aft.  A pair of missiles (one on each arm) could be launched every 9 seconds.  Thus, the ship’s overall firing rate was 4 missiles every 9 seconds (a missile every 2.25 sec) – a respectable rate and quite adequate for almost any scenario.  Given the Navy’s typical shoot-shoot-look engagement sequence, this rate of fire seems perfectly adequate. 

The Burke class carries 96 VLS cells which provides enough missiles for air defense (especially with ESSM quad packing) and a useful quantity of Tomahawk cruise missiles.  To be fair to the arm launchers, that number of missiles was not believed necessary at the time.  Had more missiles been deemed desirable, a third launcher could have been added or the existing standard missile magazine could have been enlarged.


The table below summarizes the advantages and disadvantages of both systems.  As seen, neither has an overwhelming advantage.  The choice of which system to select depends on which factors one chooses to prioritize.

Firing Rate
Time To Target


Magazine Survivability

Minimal Deck Space

Firing Arc

Larger Missiles

Missile Availability


Launch Failure Damage

You can decide for yourself which system you prefer but the key finding in this post is that the supposed superiority of the VLS is nowhere near the absolute given that everyone believes.   In fact, for the most common surface to air engagement scenario that we’ve documented in previous posts – an incoming missile first engaged at the horizon with ESSMs – an arm launcher which can point directly at the target and get missiles to the target faster may well be the better choice.


(1)Wikipedia, “Mk26 Missile Launcher”, retrieved 3-Apr-2020,


  1. One advantage of VLS that is overlooked at times is that in the same amount of space, you can carry more missiles compared to a magazine + launcher. If we look at the Ticonderoga-class cruisers, we had a Mark 26 launcher with 44 missiles in the magazine. In the VLS Ticonderogas, in the same space we can now fit 64 cells (3 of which were used by the RAS crane, so 61 available missiles).

    To highlight another advantage of VLS cells, because missiles are stacked vertically, we can use a single cell to store multiple missiles of the right size - ESSM is quadpacked into Mark 41 cells, and I've seen schematics of fitting two SM-2 missiles into the larger Mark 57 VLS cells.

    I'm not sure that deck space is a persuasive argument, however. I've looked at the many ships with arm launchers and the deck space above the magazine is left empty, unused.

    1. "you can carry more missiles compared to a magazine + launcher"

      I don't think so but I'm not 100% sure because I don't have the dimensions in front of me. Consider, though, the launcher magazine has the missiles stored vertically, side by side (in concentric rings, if I remember correctly?). That's as close as they can physically be. By comparison, the VLS has the missiles widely separated, on a relative basis, each in their own cell. The launcher magazine requires less space. I'll see if I can dig out the old dimension drawings I've got filed away somewhere to confirm.

      Additionally, exhaust and utilities are built into the VLS internal space whereas the launcher does not require such. Again, the magazine requires less space.

      Regarding ESSM, if you can quad pack a cell you can quad pack magazine storage, so to speak.

    2. As I recall from the drawings I'd seen, on the Ticos you have the Mark 26 launcher, then immediately below that is the missile handling machinery, which takes up a fair amount of space, and then you have the magazine. Otherwise, you'd expect that there would have been a decrease in the number of missiles carried, but we see an increase instead.

    3. Here's a drawing of the Mk26 missile launch and magazine system. Clearly the missile storage density is far greater than a VLS system.

      Mk26 Missile System

    4. They were both designed to fit the same SSES weapon module dimension. 44 missiles 14.5" diameter, 2200 lb limit vs what we have.

      Their used to be a schematic on line with both systems overlaying the module space, but I can't find it.

    5. "SSES weapon module dimension"

      I'm familiar with the A and B 'pit' sizes. What I don't know is what size VLS (8 cell, 32 cell, 64 cell) corresponds to which pit size and what pit size the Mk26 fits in.

    6. Empty deckspace in peacetime has value, in that it may mean more easy modification in war.

      If we look at photos of ships before WW2, and again at the end of WW2, the most striking observation is that by the end of WW2 weapons are seemingly attached everywhere there is spare space, and many places where there isn't.

      Likewise, army vehicles that have clean unobstructed roofs in peacetime, are festooned with weapons, kit and armoured panels by the end of conflict.

      In wartime our accepted compromises shift in favour of firepower. They should in peacetime also, but for whatever reason this doesn't seem to happen.

      Even if VLS displaces less volume than an arm-launcher+magazine, prioritising deckspace over internal volume has some value, in that it allows us to consider attaching non-deck penetrating weapons in conflict.

      I imagine attaching weapons everywhere causes all sorts of issues with power, data, EM interference, and conflicting fields of fire/arcs of rotation. But those considerations have never stopped us before in times of war.

  2. @ComNavOps: you discussed firing rate, and I want to piggyback off that with two observations:

    1) As you noted, in VLS the missiles are immediately available for use. With the Mark 26, the missiles need to be transferred from the magazine to the launcher: a matter of seconds, to be sure, but seconds can count in combat, and this is another potential point of failure.

    2) In terms of throw weight, VLS can theoretically put more birds into the air than Mark 26 launchers. Assuming that the combined VLS rate of fire is 2 missiles per second, we're looking at 60 missiles in 1 minute. Meanwhile, 1 missle per 2.25 seconds means that the Mark 26 launchers will put 26 missiles in the air in one minute.

    There is, however, a caveat to these workings: this throw weight, while mathematically impressive, is of debatable relevance in combat. Burkes have 3 director radars, and only 4 guidance channels per radar, meaning that at any one time Aegis can only control 12 interceptor missiles. Now, the USN and JMSDF are pursuing active radar homing interceptor missiles (ESSM Block 2 and XRIM-4, respectively) to perhaps mitigate this issue, but that's still a ways off before those missiles become a reality and the ability exists to exploit this theoretical increase in throw weight.

    1. "There is, however, a caveat to these workings:"

      There's a much bigger caveat than control channels, though that is significant. The bigger caveat, as I mentioned in the post, is EFFECTIVE missile launches. When a missile explodes, whether it hit its target or not, it fills the sky with debris which obscures the radar picture. Thus, you could have a never ending stream of missiles spaced one second apart but after the first one explodes, all the rest become, essentially, unguided. This is why the standard Navy engagement sequence has been shoot-shoot-look. Two missiles are launched and then the defense waits while the radar picture resolves enough to know what happened. The sequence is not shoot-shoot-shoot-shoot-shoot-shoot …

      Thus, a missile every couple seconds is about as much as can EFFECTIVELY be used. Therefore, the EFFECTIVE engagement rates are approximately equal.

    2. I wonder if this is part of the reason they are making so many hit to kill missiles. If there is no poof you know you missed.

    3. "The sequence is not shoot-shoot-shoot-shoot-shoot-shoot …"

      Very true. Life isn't a videogame where you mathematically stack outgoing firepower numbers against incoming firepower numbers in a spreadsheet. The only firing sequence that is continuous shooting is a cruise missile strike, but even then, given you're firing at fixed targets from a 1600km offset, well out of detection range of any enemy sensors, arguably you aren't under the same pressures that mandate you to flush all your cells at one go.

    4. @Andy:

      IMO, the move to hit-to-kill missiles is more driven by the fact that as missile size decreases, warhead weight decreases, and at a certain size, you have to choose between fitting in a guidance package or a warhead.

      Theoretically speaking, smaller point defense hit to kill missiles mean that you can carry more PD missiles in the same space, allowing you greater throw weight in the situation where the Chinese now have actual carriers and can generate 100+ missile salvoes from the air wing and desron.

  3. I don't see the firing rate as that much of an issue as the limiting factor is how many missiles can you control in flight at the same time.

    1. Well, actually, the limiting factor is tracking the target and being able to discern the one legitimate target from the sky full of exploded debris. Even if you could control a thousand missiles at once, if you can't discern the legitimate target it does you no good.

      I've stated that what we need is not an uber-Aegis radar system that can see a mosquito at a million miles but, rather, a small radar that can distinguish a real target from debris at 0-20 miles (the radar horizon).

    2. Isn't the point of being able to discriminate small targets on Radar being able to classify them as either debris or real targets, and then assigning missiles as necessary?

    3. "Isn't the point of being able to discriminate small targets on Radar being able to classify them as either debris or real targets,"

      No. A radar can't readily distinguish between, say, a fist sized piece of debris and a fist sized cross section of an incoming missile. Worse, the radar return becomes a jumbled mess of a million returns of all sizes with, possibly, one of the returns being a real target. It's like picking out one specific tree in a forest - they all look the same. It's like picking out the mosquito from a swarm of flies - they all look the same. Until the radar return clears, you just have to wait to see what remains.

      The phenomenon you're alluding to is resolution. Resolution may allow you to see each individual piece of shrapnel but it won't tell which piece is inert and which is a target. Also, if you vomit your entire magazine, as some people are suggesting, you then have to discriminate between your missiles and the enemy missiles. If you watch the debris and incoming/outgoing missiles long enough (on a radar time frame), you'll eventually be able to discern the target from the rest but that takes time and every second you have to wait means that the real target, if any, is approaching at supersonic or high subsonic speed.

    4. "No. A radar can't readily distinguish between, say, a fist sized piece of debris and a fist sized cross section of an incoming missile. "

      Actually it can, to some degree, based on doppler return. Debris flying towards the ship might look more like a missile, until it fell to the surface, but debris flying perpendicular or away from the ship could be discriminated.

      Same goes for outbound missiles vs inbounds.

    5. "Debris flying towards the ship might look more like a missile, until it fell to the surface,"

      And that's the problem. As you have multiple missiles exploding in close proximity to the real target, you flood the sky with hundreds/thousands of target size pieces flying towards you (an explosion sends debris in a spherical pattern so some is always coming straight at you) for a period of time. Until they slow and drop, you have no idea which are targets and which are not.

      You also have saturation. I'm not aware of any radar that can simultaneously track the thousands of targets (debris) that exploding missiles will generate and instantaneously sort the real from the debris. Again, given enough time, it can but time is the critical enemy in a missile engagement. That's why the Navy uses shoot-shoot-look. They have to wait for the radar picture to clear.

    6. You're watching too many movies. The debris from a missile hit isn't an explosion like a bomb and the radar can rapidly discriminate between debris and inbound missiles. We use shoot shoot look shoot because they don't want to waste missiles and the probabilities of the first two missiles of scoring a kill are VERY high individually so it's extremely unlikely the target is still alive.

      The rail launchers were terrible and the hydraulics failed all the time. The Mark 26 leaked hydraulic fluid from the day it as commissioned to the day it left service. There are several "single points" of failure on a MK26 that render all the missiles out of service from the hydraulics to arm failures to the magazine itself. By comparison every single missile is ready to go on the VLS and your perceived advantage of the mark 26 is more than compensated by the fact that you have to load the missiles for the first shot. The advantages of deck space and armored magazine are vapor wear. You can't put anything in that deck space because the launcher moves at a really high rate of speed and no matter where you are in that circle there's a chance that you're facing the back blast of an out bound missile. The extra deck space is completely unusable.

      The armored magazine is no protection at all for the launcher. Any hit to the weather decks capable of damaging all 8 modules of the VLS will absolutely eradicate the MK26 launcher. Truthfully I wouldn't count on either being able to fire if the ship was hit by something serious but if either has a chance to still work it's the VLS from an undamaged module. The top of the VLS is infinitely more protected than the rails, hydraulics and arms of the MK26. In fact you could quite possibly completely disable the MK26 with small arms or an RPG from a patrol boat and you wouldn't even be able to hit the VLS.

      The vectored thrust MORE than compensates for the 9 seconds of movement between salvos for the MK26. In fact it likely saves you 7-8 of those seconds. Giving you a massive advantage.

      Truthfully the ONLY true advantage you mentioned for the MK26 was the explosive ram for pushing a misfire over the side. EVERYTHING else favors the VLS.

  4. "The Perry class frigates had a Mk13 single arm launcher with a 40 missile magazine. By comparison, we’re struggling with today’s frigate designs to get 32 VLS cells to fit into a design. The US Navy’s new frigate design, for example, is spec’ed at 32 VLS cells, a 20% decrease in capacity from the Perry class!"

    That's a little misleading as ESSM is quad-packed in a single VLS tube. With 32 cells, one could have 16 cells for Standard Missiles and 8 cells for ESSM providing 48 SAMs in total, leaving 8 cells for other missiles.

    1. "That's a little misleading"

      Your comment is a little misleading. You're comparing something that didn't exist during the arm launcher days to something that came to be just relatively recently. Had quad-packed ESSMs been a thing back then, I'm sure they could have greatly increased the missile magazine storage density. If we wanted to build an arm launcher today, we'd undoubtedly design the missile magazine to accommodate densely packed ('quad packed') ESSMs.

    2. With all due respect, my comment isn't misleading at all. You made a comparison between the two systems and concluded that there is a 20% reduction (40 versus 32) in the number of missiles a 32 cell VLS array could carry. I only pointed out how it is possible to carry more missiles, specifically SAMs, with 32 VLS cells compared to the Mk 13 launcher of the Perry class.

      And, according the Navy Fact File, ESSM came into service in 2004, about 6 years before the last of the Perry class started to be decomissioned. So, their service life overlapped by some 6 plus years as the last of the Perry class (10 ships) were decomissioned in 2015.

    3. ESSM was not around when the Perry class was being designed.

      "You made a comparison between the two systems and concluded …"

      Yeah, that's fair. I did make that comparison. However, while you pointed out that VLS can contain multiple missiles per cell, I point out that a modern version of an arm launcher would, undoubtedly, also have multi-missile storage so it's probably back to the original conclusion.

    4. A 32 cell VLS system can carry a maximum of 128 ESSMs. Assuming the new launcher takes up the same volume as the one it replaces, the new design rail launcher would need to be able to carry 3 ESSMs for every Standard Missile to provide a similar capacity. That sounds like a bit of a stretch, but it might be doable if you can shrink the size of the missile handling equipment to make more space for missile storage.

  5. There is a "point defence missile" version of CIWS.

    The up and over of a VLS might be catastrophically slow, in a small number of cases, but its unlikely to be an issue in most.

    Another point just occurs, a vls battery can have 32/64/128 different missiles ready to go.
    A single or double arm laucher can only fire that which is loaded, and the missiles will suffer wear from the sea

    1. "but its unlikely to be an issue in most. "

      I've previously documented that tip over is likely to be extremely important in likely AAW scenarios.

      "missiles will suffer wear from the sea"

      ???? Missiles are not stored on the launcher. They're stored in the below deck magazine and loaded as needed.

    2. Playing the double edged sword with this tip thing. It's not an issue for a cold launch system.

    3. "Missiles are not stored on the launcher. They're stored in the below deck magazine and loaded as needed."
      Ah, all the or shots I've seen show them loaded, i assumed they as lways were

    4. "Ah, all the or shots I've seen show them loaded"

      It is doubtful that you've ever seen an actual missile on the launcher. What is commonly seen is an inert, practice missile that is used for exercises and mechanical checks on the system. The practice missiles are identical in appearance except that they are painted with a blue nose. Most people don't realize they're seeing practice missiles and think they're the real thing.

      If you've actually seen a real missile then it was likely video of a practice launch which tend to occur very slowly with each step taking a prolonged period of time while conditions are carefully monitored. In a real combat shooting scenario, the entire process happens in seconds which, again, means there is no prolonged 'sitting on the rails'.

  6. There are also foreign perspectives on how to build the VLS, namely Russian and Chinese versions. Some of their VLS systems use cold launch systems to kick the missile out of the VLS before the rocket motor ignites. Meanwhile, the VLS is angled slightly so that if the missile's rocket booster fails it'll land back in the sea.

    The downside is that the plumbing for a cold launch system takes up even more internal space, but, hey, at least you don't have a hot missile crashing back on top of your VLS tubes.

    1. The big reason why the Russians use the cold launch is due to ammunition reliability issues. They've had problems with ammo malfunctions since soviet times. This goes from bullets all the way to missiles.

  7. A big factor against VLS is reloadability - they can't be reloaded at sea, at least in the current designs. Once you're out of missiles you are out of the fight until you can return to port. You can't even re-arm from an AO/AOE. This is even more critical IMHO for SeaRAM with only 11 rounds.

    1. SeaRam isn't a VLS so if that can't be reloaded at sea why would an older arm launcher for even larger missiles be re-loadable at sea?

      Older VLS ships had a crane to do it but it was found to be not worth it just like in WW2 where big guns and torpedoes where not reloaded at sea.

    2. Agree that SeaRAM is not VLS. However the SeaRAM installations to date have not been provided with any sort of underway reloading capability for some reason. I think it has to do with the height of the launcher above the deck.

      The loader module in the older VLSs had 2 problems: 1) they just didn't work well; and 2) the alignment tolerances were/are so tight that they couldn't load when there was any ship motion at all - even at anchor.

    3. "SeaRAM installations to date have not been provided with any sort of underway reloading capability"

      Actually, I think it can be reloaded at sea. There are many Internet photos of RAM reloading and they appear to be at sea although I'm not 100% certain. The reload involves a small platform/crane assembly that appears to attach to/around the RAM and then the missiles are reloaded manually using the small crane. It appears to be quite a cumbersome procedure involving several people and is certainly not something you'd do in the middle of a battle. Presumably, SeaRAM is similar.

    4. It shouldn't be appreciably harder to reload RAM at sea - Sea Sparrow is loaded into the 8-cell box launchers by ships crew, and a Sea Sparrow is 3 times with weight of a single RAM.

    5. "It shouldn't be appreciably harder to reload RAM at sea"

      It's not! However, that's not to say it's easy or quick. It's not! There are plenty of videos and photos of reloading and it's quite obvious that it's a long, labor intensive procedure. Not difficult (assuming fairly calm seas!) but not quick and not useful during a battle.

    6. The earlier versions could be reloaded at sea but the Navy decided that was so impractical that they removed the cranes. It would be pretty unlikely to make much difference to be realistic. It's improbable that the Navy even has enough missiles to load the 8000 or so VLS cells it has. Ships headed back from patrol unload most or all of their missiles so they can be transferred to outbound ships. Loading/transferring the missiles at sea was slow and dangerous and required a really calm sea state. I think the real advantage of the cranes was possibly that a ship that had a critical problem with one launcher would have been capable of reloading itself by transferring launcher to launcher. It still would have taken days to accomplish which is a very long time in a modern warfare scenario.

  8. Firing Arc. Arm launchers have a limited firing arc because the ship’s superstructure masks portions of the firing arc. Assuming the ship has time to maneuver to unmask its launchers, which would almost always be the case, this is not a serious drawback but it is still a limitation.

    The RN found that to be a pretty big drawback during the Falklands campaign where line of sight was blocked by islands and other ships as well as superstructure when dealing with low flying jets and sea skimming missiles.

    A VLS with the missile going straight up allows it to clear obstacles and gain an energy advantage when tipping over to engage low flying targets.

  9. It would seem to me that while the two systems are fairly even in terms of combat capability, the VLS may offer more easily adaptable as different weapons become available in the future. (This is my perception).

    If this is true, and the combat capabilities are roughly equivalent, then I can understand the desire to pursue VLS only.
    Shame, because it doesn't take into account that the arm launchers firing & swiveling for reloading looks way more badass (badass category is missing from your table)!

  10. First off, just need to say one armed bandit.

    Second, the convergence toward VLS can either be attributed to the fact that common factors lead to common solutions, or to group think. Take your pick.

  11. An updated arm launcher design should take advantage of the prepackaged VLS missiles and load the container and the missile on the arm at the same time. The containerized missile would be protected from the elements until fired and would use the same supply chain as the VLS ships. The updated design would interface with the container rather than the missile directly. After firing, the next containerized missile would push out the previous spent container or a system could be designed to eject the container before the next missile is loaded. Covers for the exit and exhaust could be built into the arms to increase the protection of the missile container and allow continuous carry of ready rounds on the arms.

    1. Another advantage that isn't mentioned is the possibility of using dumb rockets. The existing one armed bandits probably can't, because missiles don't need the precise bearing and elevation controls that rockets do. Firing dumb ammo is cheaper than missile. It's good for fire support missions and maybe other uses like fast boats (sub-munitions are a beautiful thing).

      I thought a good idea is to make a mount for MLRS pods. That way any munitions for the land use are available for ship use and vice versa. Although I hope the Marines don't try to use torpedo pod. They would start looking sillier than they are now.

    2. Can't you envisage the CMC saying, "Today, Marines we have full submarine fighting capacity, Semper Fi."


    3. It's not feasible nor practical to load the existing cannister onto a new rail launcher. It would also add immense weight to the arms and make them more likely to fail. On top of that the cannisters are reusable and expensive. You're not going to just dump them. The VLS cannisters need to be connected to the ship in 3 ways, grounding, a very difficult to attach 141 pin connector that allows the launcher and ship to monitor the missiles and a fire suppression/warhead cooling system that is charged with pressurized water. It's virtually impossile and to do what you're suggesting and even if it was possible it would lose all the benefits of VLs and likely wind up with a worse version of the MK26. The rail system launchers were nowhere near as good as VLS despite the suppositions being presented here. Most of the OP's ideas are simply wrong.

  12. An updated arm launcher design could be designed to protect the deck from the exhaust of a vertical launch. The arms don't have to point in the direction of the threat. A vertical launch from an arm launcher would be no worse than from a VLS. The missile management system would direct the type of launch (horizontal or vertical) based on any obstructions in the path a horizontal launch.

  13. "Pointing. The arm launcher points directly at the target and the missile launches horizontally rather than vertically."

    With a rail launcher, you wouldn't aim your missile directly at the target, but at where you expect to intercept the target. Say there was a missile heading toward the carrier that you're protecting, firing at the target could force the missile to fly a long arc in order to catch the target. Flying to the intercept point conserves energy and which might be needed later if the target is maneuvering. This all depends on speed and direction of the target relative to the firing ship.

    Regardless of the launch system, a missile is usually launched knowing the position and speed of the target and then guides itself to the intercept point where the terminal guidance takes over and the missile destroys the target. Some missiles have the ability to accept target updates from the firing ship which it uses to adjust its flight path.

  14. This seems like an opportunity to use both systems on the same ship.

    A ship has limited deck space so a combination of VLS and arm launcher seems reasonable.

    The arm launcher would free up deck space by reducing the number of VLS launchers needed.

    The VLS would be available if the arm launcher jammed or was damaged (assuming the arm launchers were fired first).

    Complementary systems.

    1. "Complementary systems."

      Now there's a worthwhile suggestion! An arm launcher could provide the point and shoot allowing for fast engagements against short range (horizon) targets and a VLS could provide for leisurely engagements at dozens/hundreds of miles.

      Very nice!

    2. A side benefit, I would think, would be to lower the center of gravity of the ship.

      Since in a sane world all those explosive missiles should be housed in armored protection, the VLS cells would add weight to the deck.

      If some of those missiles are instead used in arm launchers they would be stored in armored magazines deeper in the hull. This would move that weight below the water line.

      If you could replace half the VLS cells with arm launchers, I would think it would help the sailing characteristics of the ship.

    3. "A side benefit, I would think, would be to lower the center of gravity of the ship."

      I suspect not. In another comment, I linked to a drawing of the Mk26 launcher and magazine. It's not really any lower than a VLS system. The missiles are stored below deck, yes, but it's not all that deep.

      If the Mk26 lowers the center of gravity, it wouldn't be by a lot. There's also the weight of the launcher, itself, which is above deck and would raise the center of gravity. So, I suspect the net difference between the two systems is minor.

    4. Yeah, that makes sense.

      I'm an ex-army guy, so I don't know a lot about ships.
      In my mind I was envisioning an armored magazine deep down in the hull.

      But that probably wouldn't work because the travel distance for the missiles from the magazine to the launcher would be too far and be too slow.

    5. "the travel distance for the missiles from the magazine to the launcher would be too far and be too slow."

      Correct. The missiles are below deck more so than the VLS but not by all that much. Find the link in the other comment and check out the drawing and you'll see what I'm talking about or just do an Internet search for 'Mk 26 missile launcher drawing' and you'll get plenty of images.

    6. "[VLS = leisurely, arm launcher = rapid point defense]"

      Is the Mk26's train rate high enough for us to be treating it like an oversized seaRAM, or is the pointing of the arm launcher largely comparable to the "tip over" of a VLS-launched missile? I'd support an ESSM-specific development of the Mk26 with sufficient train rate to justify exactly that, but I would question the wisdom of using this system on the grounds of improved time to launch compared to VLS; the versatility of having the whole magazine "chambered" outweighs any minor superiorities in the Mk26 load/train/fire cycle if this is our primary motive for using an arm launcher.

      "[MK 26 magazine isn't very low, or well protected in Virginia/Tico designs]... [storing the magazine deeper would increase the travel time/distance to the launcher]"

      While this is bad practice for defensive AAW missiles - which should be kept as ready to fire as practical - I'd rather see a relatively slow-firing, well protected system to handle anti-ship and land attack missiles in a hypothetical heavy cruiser or BB; they could even integrate the magazine handling systems so you don't lose dozens of missiles if you lose one of the launchers. ESSM quad-packs for such ships could be housed in peripheral VLS, conventional VLS, or a purpose-built "oversized seaRAM" launcher/magazine system.

    7. "Is the Mk26's train rate..."

      Just saw the replies to Fighting Irish's comment. Load/train time is clearly a non-issue for the first salvo if the ship isn't surprised by the inbound missile raid. I'm not as sold on the sustained rate of fire; I agree with your assertion that this usually isn't an important figure of merit, but Anon2 points out that there are non-trivial situations where it could be.

      All in all, I still like the description of VLS and arm launchers as "complementary systems", and I think there's definitely value in at least considering their use in new builds, whether in conjunction with VLS or not.

  15. One thing I've not seen mentioned is they fired Harpoon as well. The magazines had SM1, Harpoon, and could fire Tartar. Australia upgraded our launchers to fire SM2 Block 111A the last SM2 that can be fired from the twin arm launchers. The last retired only 6 months ago.

  16. PS we also installed 8 Mk41s for ESSM.

  17. As far as launcher reliability in regards to battle damage couldn't you have a armored launcher like a armored MLRS? Using such a system you could also have it larger on a ship so it could load say two missiles on a standard sized launcher or 4 or more on a larger one.

    You could have say a active load out of say 4 essm in one side the other holds the ready SM6 or whatever you need.

    I mean look if the Army can do it on a tiny platform....

  18. ComNavOps " Well, actually, the limiting factor is tracking the target and being able to discern the one legitimate target from the sky full of exploded debris. Even if you could control a thousand missiles at once, if you can't discern the legitimate target it does you no good. I've stated that what we need is not an uber-Aegis radar system that can see a mosquito at a million miles but, rather, a small radar that can distinguish a real target from debris at 0-20 miles (the radar horizon)."

    Possible radar with the best possible clutter suppression.

    Weibel Scientific a Danish radar company have become very successful by specializing in Continuous Wave radars, CW, which transmit constantly and therefore requires two antennas, one for transmitting and one for receiving the return echoes.

    A CW radar frequency beam that hits a moving target causes a return with a changed frequency, subtracting the return frequency from the transmitted frequency gives the velocity of the target, the Doppler effect, and the great plus with CW technique is its unique ability to suppress clutter caused by differentiation of very low speed returns and thus making easy to filter out.

    To measure the range, the CW output must be changed in frequency, either in steps, Multi-Frequency CW or by modulating the frequency, Frequency Modulated Continuous Wave, FMCW, and also being able to see zero Doppler targets moving radially to the radar itself. Typically the FMCW technique uses longer duty cycles and lower output power and often used in Low Probability of Intercept, LPI, radars as the low transmitted output power is additionally divided over a large frequency bandwidth (the modulation of the frequency). FMCW radars are however more susceptible to clutter than the pure CW, Weibel developed the combination of transmitting CW and FMCW simultaneously in the same radar, thereby being able to detect and discriminate/separate targets in both range and velocity and to have the best possible clutter suppression. With the combined waveform technology, Weibel radars are highly suitable for Surveillance as well as Fire Control, both on Naval vessels and on ground eg Weibel  build the X-band (8.5 gigahertz/GHz to 10.68GHz) frequency modulation/continuous wave fire control radar which has a low power of 40W and a range of circa 16.2 nautical miles (30 km), the Kongsberg and Raytheon’s NASAMS radar, contract with the US Navy to deliver muzzle velocity radars for the AEGIS destroyer fleet and the tri-lateral cooperation between Lockheed Martin, Terma and Weibel on the Ground Based Integrated Discrimination System (GBIDS) with Weibel’s unique radar technology.

    1. Nice explanation. Thanks.

      One of the problems in an engagement is that the exploding missiles, whether hits or missies, generate high speed, moving debris in a 360 degree pattern. Thus, even a radar such as you've described, would be presented with thousands of 'valid' targets until the unpowered pieces begin to slow and fall. It would be liking shooting a pistol bullet into several exploding grenades. There would be LOTS of pieces around the same size (the bullet among them) moving towards you at high speed. Until all the non-bullet pieces slow and fall, you won't know which was the real bullet.

      To the best of my knowledge, no one has ever addressed the problem of discriminating a real target from a sky full of exploding debris. Again, this is why the Navy uses the shoot-shoot-look engagement sequence, to allow the radar return to sort itself out. That works but it drastically reduces the number of engagement opportunities you get.

    2. In news just in Chile's Navy has bought two Adelaide Class (Perrys).

  19. How long does it take to unload and reload an arm launcher? Say you need to swap out a SAM for an ASROC or antiahip missile?

    Another question? What do you do if you have a missile on the rail that doesnt launch when the button is pushed? Was there a way to eject that missile over the side in a combat scenario and get a good missile out on rail, or were you stuck looking at it like a dud firework waiting for it to go off on its own?

    Would you have had to send a sailor out with a ladder to check the wires in the middle of a missile attack? Is your twin arm now a single arm? Is your Perry class now a gunboat instead of an Odd FFG?

    I'd rather just select a different missile in a different cell and figure out my dud after the shooting stops.

    1. First, you need to understand that missiles are not stored on the rails. The missile launcher arms are empty until the decision to launch has been reached and a missile type selected. The launcher then loads the missile which takes 7-9 seconds depending on the launcher version.

      To launch, the missile is ejected off the rail and the missile motor ignites. If the motor fails to ignite, the missile simply drops into the sea. I saw a video of that exact scenario once which occurred during Desert Storm. Seeing a missile eject off the rail and then pause and drop into the sea was humorous although in a combat situation I'm sure it would not be as funny.

      Missiles have minimum safe arming distances that they must travel exactly to avoid blowing up on or next to the launching ship. So, there is no possible scenario of a 'dud' sitting on the rail waiting to explode.

      I suppose there is the possibility of the rail eject mechanism not working which would leave a missile on the rail but I've never heard of that happening. Similarly, it is possible that the VLS covers might not open thereby preventing a launch or the ignition signal might be shorted out and not function or the missile motor might not ignite or …

      You're attributing all manner of possible failures to the arm launcher and none to the VLS. Be fair and if you're going to engage in failure mode speculation then do so equally for both systems.

  20. The MK 10 and MK 13 launchers has a dud jettison system, so I presume that the MK 26 did as well. It was basically a hydraulic plunger that punched the missile off the launcher and over the side.

  21. To make the best of two worlds, perhaps both systems could be built onto a single platform, such as a double ended destroyer.

    Mk 29 launchers fore and aft, to engage immediate theaths over the horizon with ESSMs, backed by RAMs in similar positions closer to the superstructure.

    32-64 VLS's in between with ASMs, additional ESSMs, ASROCs etc. 5 inch guns fore and aft, phalanxs's on the sides, heavy torpedoes. No hangar, no flight deck.

    This would be a symmetrical ship akin to the virginia class cruiser but half the size or less.

    1. Like having RAM/SEARAM for point defense and VLS for further out ;)

    2. " best of two worlds"

      Potentially a very nice design!

    3. They would look good on the fore and aft decks of Cleveland class cruisers designed as Ticonderoga replacements, supplemented by VLS.

      They would also look good on the fore and aft of the superstructure of Iowa class battleships and Alaska class and Des Moines class cruisers.


  22. "Pointing. The arm launcher points directly at the target and the missile launches horizontally rather than vertically. This means there is no delay while the missile tips over and acquires the target. Therefore, the missile gets to the target faster than it would from a vertical launch system."

    The focus appears to be on defeating sea-skimming antiship missiles. Is there any analysis that proves a rail-launched missile can hit a target faster than a vertically launched missile? And, if so, is that true of all ranges or is that valid at closer ranges?

    At very close ranges, I can see the advantage of a rail launched missile. SeaRAM, though launched from a canister, is launched toward the target at a shallow angle, like a rail-launched missile would be, and is good out to 6 nmi or so.

    But, a vertically launched missile like ESSM, can tip over quickly to fly towards the target. And, it doesn't necessarily need to acquire the target just after launch. As I understand it, ESSM is launched knowing the target's speed and direction and provided with course updates during its flight. When its close enough, the terminal guidance takes over and destroys the missile.

    It would be interesting to know the minimum effective range of a vertically launched ESSM compared to that of a box launched ESSM.

    1. "Is there any analysis that proves a rail-launched missile can hit a target faster than a vertically launched missile?"

      You mean other than common sense? If you fire the same missile directly at a target versus 90 deg off target and then have to wait for the missile to tip over and begin its horizontal travel do you somehow think it would occur faster than a direct fire? Is this a trick question?

    2. The VLS missile has to "tip over". But your arm-launcher has to start at loading position, load a missile, swing to launch position and fire.

      No storing weapons on the rails,a you're not allowed to have your launcher conveniently pointing in the right direction when the target appears. That's gaming the test.

      Empty From loading position, to the furthest limit of travel. That would be the fair test vs a VLS launch.

    3. That's no even remotely how an engagement works. In this day and age, total surprise attacks do not and cannot happen. You always have some idea of where the enemy is. With the various surveillance assets, you probably have a pretty decent idea of when to expect an attack.

      Having some idea of when to expect an attack, yes, you absolutely load a missile onto the rail and point the launcher in the anticipated direction. At that point, it's just how fast can your missile get to the target.

      For VLS, the same applies. So, at the moment that a launch decision is made, both systems are ready to fire and the arm launcher missile gets to the target first.

      By the way, you seem to either have a very limited understanding of how VLS works or you're just trying to put together a contrived scenario. Contrary to what you tried to present, ships don't have an operator with his finger poised over the VLS launch button just waiting for the slightest target indication. Unless combat is anticipated (see the previous paragraphs), the system is idle. If a target were to appear out of nowhere, it would take some time for the command element to even reach a 'combat' mindset. VLS has to be readied. It doesn't take long but there is a delay. The decks need to be cleared of personnel. Targets need to be assigned. Target data needs to be sent to the VLS. Cell covers need to open. And, finally, a launch can occur.

      Now you understand the realities of launching.

      From a 'ready to launch' condition, which is the only one that matters, an arm launcher gets missiles to the target faster.

      We're not going to pursue a ridiculous debate.

    4. The arm launcher has the advantage for an initial engagement, when you can pre-load and pre-queue the launcher. For subsequent engagements in a raid, the VLS wins.

      If there is no pre-queueing (missile surprise attack), VLS wins.

      VLS missile tip-over only adds a second or two to the launch. Not very much.

      VLS is more reliable, less maintenance intensive, and not any less compact when you add all of the under-deck Mk26 launcher infrastructure.

      When dealing with a large inbound raid, especially from multiple bearings, VLS really shines. Of course limited fire control channels currently hamstrings the max number of simultaneous engagements. However active missiles like ESSM BLK II, SM-6, and SM-2 BLK IIIC will circumvent this limitation.

    5. "For subsequent engagements in a raid, the VLS wins. "

      Did you read the post? An arm launcher has the same EFFECTIVE launch rate as VLS.

      "VLS missile tip-over only adds a second or two to the launch."

      That's absurdly incorrect. Go watch a VLS launch video. The missile takes about a full second to even clear the cell and then goes up a thousand feet or so and then begins to arc over and then has to descend (assuming the incoming target is a sea-skimmer). That's some significant time when an incoming missile is traveling at supersonic or high subsonic speed.

    6. "Did you read the post? An arm launcher has the same EFFECTIVE launch rate as VLS."

      That's not really the case. You made a judgement that a missile every 2.25 seconds is SUFFICIENT. That's different from what either can actually do.

      A Tico with two VLS systems can fire two missiles per second (of any type), one per VLS. That's four missiles in the time it takes a Mk26-armed Tico to fire one missile, on average.

      The debris argument only matters at all if the enemy missiles are flying down the same bearing. If they used waypointing, came from multiple launch points, or were even launched from multiple, line-abreast aircraft that won't necessarily be an issue. And if the are going after different ships in the task force, they won't be on the same bearing either.

      Consider a regiment-sized (~20 A/C) strike of JH-7s, each carrying a pair of missiles, forty inbounds. Not at all an out-of-bounds possibility.

      A Tico with Mk26s would take three minutes (180s) to fire off the 80 missiles needed for the initial shoot-shoot. In those three minutes, the last engaged missiles can fly up to 30nmi (assuming 600kt subsonic missiles).

      A VLS Tico would only take 40 seconds to fire off 80 missiles at max rate. The last engaged missiles only fly 6.6nmi.

      Now that's optimum, obviously. There are other limiting factors.

      Of course if either Mk26 has a failure during the 20 launch-reload cycles each must perform, then ROF drops by half. VLS is much less likely to have a mechanical failure, especially a total system failure.

      There is a timer on this ESSM shot.

      Launch happens around 16:30:04. Tip over starts at 16:30:05. Fully tipped and on its way at around 16:30:06.

    7. "If you fire the same missile directly at a target versus 90 deg off target and then have to wait for the missile to tip over and begin its horizontal travel do you somehow think it would occur faster than a direct fire?"

      In the limited case of engaging a close in threat, like an antiship missile coming over the horizon, then a horizontally launched missile has the advantage. This explains why SeaRAM is launched the way it is.

      But, at longer distances and higher altitudes, I see it as a wash, in terms of the time it takes to hit the target, between a missile launched at an angle towards the target or launched vertically.

    8. " longer distances and higher altitudes, I see it as a wash"

      At longer distances a few seconds more or less don't matter. However, as I've documented in posts, that's the least likely engagement scenario. The sea-skimming, radar horizon engagement scenario is far more likely. I've stated before, and I'll repeat, we should be de-emphasizing Standards and emphasizing ESSM.

    9. Just to wade in, the ability to quadpack the ESSM (or theoretically ninepack an AMRAAM missile body or 16- pack a Sidewinder missile body) is a useful capability of the VLS that doesn't reflect in your comparison. Your 32-cell FFG could potentially carry 128 ESSM, compared to the OHPs 32 SM-1MRs.

  23. Something else between these two systems I consider important: Reloading. In previous decades, I'd read about the struggles of missile reloading at sea - but it could be done. And as far as I understand, you have to port to reload VLS. If this is close to accurate, plus all the above comparisons, then it seems a hybrid approach - installing both a Rail and VLS launch system - would give a warship the best possible offensive/defensive options in combat. So why havent naval designers gone this route?


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