Time to Ditch the 57mm?

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The MK46 Mod 1 weapon system fires a round during a live-fire qualification exercise aboard the amphibious transport dock ship USS New Orleans (LPD-18). US NAvy Photo

DefenseNews reports on the controversial decision to replace the planned installation of the 57mm Mk110 on the DDG-1000s with the smaller, lighter 30mm Mk46.

The remarks by the project manager in defense of the decision seem to raise questions regarding the Coast Guard’s choice of the 57mm Mk110.

640px-US_Navy_100622-N-7058E-161_The_littoral_combat_ship_USS_Freedom_(LCS_1)_fires_its_MK_110_57mm_gun_during_a_surface_gunnery_test
Photo: Mk110 57mm gun on USS Freedom (LCS-1) during surface gunnery test firing

The Mark 110 57mm gun, “was nowhere near meeting the requirements,” said Capt. Jim Downey, program manager for the DDG 1000 Zumwalt class.

In fact, Downey said, the 57mm gun — selected years ago for the DDG 1000 as a close-in weapon and in service as the primary gun for the littoral combat ship and Coast Guard national security cutters — is overrated.

“They were significantly over-modeled on the lethality,” he said. “The results of the actual live test-fire data was that the round was not as effective as modeled.”

For the DDG 1000’s particular requirements, however, Downey said the 30mm met more overall performance points than the 76mm or 57mm guns. All three guns were part of his program review, with the 30 coming in just ahead of the 76 and significantly ahead of the 57.

The program manager also contends the lighter weight of the Mk46 was not a consideration.

“That is absurd, the fact that we changed the guns for weights,” he said in a September interview. “The weight had zero, absolutely, 100 percent nothing to do with the decision on the guns.”

Still it is hard not to believe the choice was a result of a misguided, overly restricted decision criteria. Surely the criteria had to focus on effectiveness against swarms of small fast surface vessels, because the Mk46 has no AAW capability. Even this scenario has to be called into question because of the short effective range of the 30mm.

One retired senior surface warfare officer questioned the choice of the 30mm, which, he said, was effective only to about 2,200 yards.

“If they’re going to use the 30mm as the answer, they’re going to let some ships get in pretty close,” he said.

“When you look … at engaging swarm boats, [the 30mm] can’t even begin to engage effectively until they’re about a mile from the ship, and by then you’re in rocket-propelled grenade range,” the retired senior officer said. “The 57,” he added, “has an effective range of about two to three miles.”

Even if the criteria are flawed, the DDG-1000 program manager seems to know something about the 57mm that the Coast Guard does not. We probably should look at his team’s data.

As I have stated before, in order to minimize the probability that extemporized weapons could disable a cutter, the Coast Guard needs a standoff range of at least 4,000 yards so I cannot see how the 30mm is a good choice.

Still, if the 30mm more effective than the 57mm in the anti-surface mission, perhaps it is time to reconsider the choice of primary weapons for the OPCs? Should we go back to the 76mm or perhaps consider the 5″. Or should we dispense with a medium caliber gun entirely in favor of small guided missiles, with perhaps a weight/space/moment reservation for later installation if we become engaged in a prolonged major conflict?

The Coast Guard must also consider countering small fast surface craft but only in small numbers, with the likely complication that they would likely attempt to avoid the cutter rather than closing the range to attack it, and for that I believe small guided missiles are a better choice than any gun.

Earlier we talked about how the OPC might be designed for wartime, but built for peacetime. Recently I have come to believe the peacetime weapons outfit of virtually all cutters, WPC (perhaps WPB) and above, should include a stabilized heavy machinegun mount like the Mk38, some small precision guided weapons (like SeaGriffin, Hellfire, or Brimstone), and light weight anti-surface torpedoes (not to say they should not have other systems). This would allow all these cutters to fire warning shots (with the Mk38), destroy small, fast targets (using the guided weapons), and immobilize even large ships from outside the effective range of extemporized weapons (using the torpedoes). Right now, I don’t believe there is a light weight torpedo with an anti-surface capability in the US inventory, so we need some other system to provide this capability, until we can get the Navy to provide an appropriate torpedo, and we need to have it on relatively small cutters because when the need is recognized the NSCs and OPCs are not likely to be available.

improvised weapons
Photo: Extemporized weapons–actually a Chinese test

34 thoughts on “Time to Ditch the 57mm?

  1. The 30mm has no anti-air capability. A radar directed 57mm with programable ammunition would give the OPC’s some anti-air capability. Given that terrorists have already used aircraft for terror here in the U.S., Coast Guard cutters, even in peace time and in a homeland security environment, should have some anti-air capability.

  2. I don’t understand this at all. Three inch and below in cannon the performance of various natures slides away quite rapidly because of reductions in the mass of the projectile and the speed (charge) have such impact. You would never compare 7.62mm, 12.7mm, and 20mm rounds would you? No. You can compare 4.5in to 6in weapons because there is some overlap in performance data that makes comparison a valid exercise. But to say 30mm and 76mm have similar performance, or more accurately hit the same criteria, but 57mm fails seems odd. That is to say what makes a 30mm good at one end of the line and 76mm good at the other are different. Say for example projectile mass (little bang to bigger bang) or rate of fire (very fast to reasonable fast). And you pick your point along that line which meets your needs. The 57mm to me seems a good compromise and it is a proven weapon system used by lots of navies. It is an accurate gun too. For it to be suddenly declared a poor performer doesn’t seem realistic.

      • I’m not curious at all. It’s painfully obvious… The weapon choice was clearly about top weight in spite of what he says. After the debacle of the LCS program, and the questionability of “success” of the DDG-1000 program with it being cut to 3 hulls, no program manager wants to admit any errors. It’s career protection…

        To say a 30mm and 76mm meet goals and the 57mm doesn’t, goes to show a bias against the 57. A statistical analysis of capabilities, such as: weight-of-fire, penetration, hit probability, costs, and magazine/ready ammunition is easy to do, regardless of how different the calibers are. The trickier part is determining/evaluating what “effectiveness” is. I would assert that this is VERY subjective, and is what Capt. Downey is hanging his hat upon.

        I’m not really blaming him, though. This is the result of the broken procurement system we have.

  3. Downey is running a program under intense scrutiny to come in on budget. The budget savings alone are what he is looking at.

    • I think they are too focused on the Islamic Revolutionary Guard Corp small boat threat. Even then, if they are protecting other units, don’t you need more range than a 30mm?

      • The swarm is a (hypothetical) threat only because modern (large) Western naval vessels are under gunned. No that is wrong. They have few guns because their is no peer threat requiring such armament; that went out at the end of WW2. ** The swarm as a truly viable idea fails for a few reasons. One, how you going to launch your attack? Sit off the coast in a flotilla of tiny boats just in case the USN or other NATO wanders past? No. Sit in harbour then and race out to attack the enemy ship (probably outside territorial waters so 12nm out) that you conveniently spot? Even if you little boats can do 60kts (which they won’t) it will take 12 minutes to get out there, 12 minutes in which the enemy will have moved, 12 minutes in which they have to spot you, they will be shooting at you before you get to shoot at them, they will be shooting at you with lots of ordinance from a very stable platform while you will have had you kidneys pulverised (and motion sickness), they will probably have their helicopter in the air, and as I said you will be an easy target because you will be going a lot slower than 60kts. The idea that a frigate 12nm out will have speed boats approaching from all angles is far fetched. Most modern warships have more than one auto cannon on each beam; aft is a bit of a blind spot but that would be a quick fix. And you can never have too many 12.7mm. It is pure fantasy. A terror attack at anchor in a harbour is a different matter. Our forebears solved that problem with torpedo nets and picket boats. Reminds me of this,

        http://en.wikipedia.org/wiki/Billy_Mitchell#Project_B:_Anti-ship_bombing_demonstration

      • As I have occasionally pointed out a WWII still air attack is much harder to deal with than a swarm of boats. Airplanes, even in WWII were faster and they moved in three dimensions.

        The reason we no longer have dozens of crew served weapons is because we do not want to pay for (and birth) dozens of gun crews.

        Beside the swarm is now really just a distraction to cover for their torpedo and cruise missile launching craft which are a very different and more serious problem. They will very definitely be launched beyond the range of the 30mm.

      • AFAIK, the 57mms were meant as close in protection for the DDG-1000 vs small surface threats, not as protection for other units or as AAW systems. From the sound of it, the extra range and effectiveness vs the 30mm of the 3P ammo wasn’t as great as advertised.

        Given this, one has to wonder if the 20mm Phalanx 1B might out-perform both for this mission (as well as having some marginal, but realistic AAW capability). I recall being unimpressed by that video of Phalanx shooting at small boat targets.

        The USCG has a different set of requirements, which the 57mm may still meet (e.g. damaging, disabling, sinking larger vessels). The USCG cutter attempting to sink that derelict Japanese fishing trawler with its 25mm doesn’t lend much confidence that anything in that size range is reliable in this role.

        http://defensetech.org/2012/04/06/video-uscgs-mk-38-cannon-sinks-japanse-ghost-ship/

        Chuck, I like your idea of equipping cutters with torpedoes, but it doesn’t seem very likely.

  4. Yes. Post 43-ish the combatants had come to realise that aircraft were just too fast and that all they could do was deter (hopefully) and put enough projectiles in the air to hit something. There is also a morale dimension to it in that the crew in a way could be seen to fighting back even if it were little more than venting frustration!

    I think we need to delineate between the “swarm” as many on defence blogs and forums seem to define it, an attack by dozens of small boats armed with heavy machine guns and hand held rocket launchers, and a coordinated attack by FAC with missiles and cannon (Jeune École). The latter can be dealt with easily by main armaments and helicopters. But as the former, even as diversion, I don’t think it is viable. Let say you were in the Gulf (you choose Mexican or Arab!) and came upon a flotilla of small fishing boats; the sort of cover put forward by many who seek to validate the swarm idea. You would go around them threat or no threat because of rules of road. If you were in a threat environment you would give them a wide berth anyway and gun crews mustered. Just don’t see it. I think it would happen more by chance by design. I think basic training would overcome opportunism.

    • Actually, I think the US Navy AAW 1943 to 1945 was very effective. It was also very expensive in terms of manpower but that did not matter so much. Unfortunately they were faced with a swarm of very smart cruise missiles that would not be fooled by today’s chaff or ECM.

      Another measure that might be taken is putting a group of marines on board temporarily. They could use their machineguns, anti-tank weapons, and even rifles to add to the ship’s weapons.

      Really the Straits of Hormuz is the only place the “swarm” of small boats has any chance at all.

      Even laying down smoke would destroy their cohesion and tend to breakup their attack.

      This has become a huge red herring.

      • Good? Or just a lot of it? And yes the wetware in the cockpit did mean that the “missiles” got where they needed. But also I think as I said above the “deterrent” effect must have played some part in the performance of even the super disciplined young Japanese pilots. Must have been horrific. Brave men on both sides.

        Marines: Well yes! Isn’t that what they are for after all? 🙂

        And I agree with your comment about smoke. Easily made with not much equipment,

        coupled with manoeuvrability,

        would produce the required results. Men in boat against men in ship with stabilised RWS with FLIR? No contest.

        Shame the ASW mortar is such a rare beast these days!

      • Remember that the US Navy used proximity fuses on the 5 inch guns for AAW in WW2. If you can do a armed UAV, how hard would it be to do a armed UMV(unmanned maritime vehicle) for a kamikaze run like what happened to the Cole.
        Or how about a unmanned submarine that detonates below the intended target.

      • Generally I think, unmanned “kamikazes” are no more dangerous than manned ones. In the case of aircraft, being unmanned can eliminate the g force limits of the pilots, but no similar advantage for surface or sub-surface vessels. Of course torpedoes are unmanned, underwater kamikazes.

      • X’es point about there being “a lot of it” is right on target. http://www.history.navy.mil/library/online/antiaircraft_action_summary_wwii.htm

        Note that 40mm and 20mm were the most effective. Note also that the number of rounds per target destroyed was above 1000 for each of those “effective” calibers.

        This doesn’t mean it was ineffective. Very few large ships were lost in the later years of the war, and as a percentage of the size of the fleet, the numbers of smaller ships lost was not too great.

        What REALLY killed the gun as an AA weapon is speed. Jet engines in aircraft and missiles made guns too slow to react and too complicated to calculate leade. (This is why CIWS still has a little difficulty dealing with subsonic missiles. Make them supersonic, and that’s why the RAM came about…)

        The swarm attack IS a red herring. The simplest and most effective solution to deal with that threat is to put a squadron or two of Apaches (or Cobras) on an LPA in the southern Gulf. Other than

    • ” If you were in a threat environment you would give them a wide berth anyway and gun crews mustered.”

      On the small and lessor armed Vietnam 82s we went among them. That was the job. At times we’d have 30 to 60 sampans around us. All of them capable of doing harm. I have no idea why an attack was never done. Perhaps the people saw the futility of the act. Different philosophy of life and religion.

      • Agree very much with you, Bill. One doesn’t always get to tactically define the situation. More often, the mission defines the tactics. It is too simplistic to say, “we’ll just always go around them.” When one realizes there is a swarm attack happening is when the boats are first spotted by the lookouts. If I were the Iranians, I’d wait for a moonless night with relatively mild seas. Do not forget that they own Greater and Lessor Tunb and several other islands in the center of the straits, and commercial vessel traffic is funnelled around those (and other Iranian-held) islands, so it’s not as simple as, “they’ll come from over there.” All that said, though, I still think it’s a red herring. The only swarm attack which has a chance is a suicide attack. Given decent surveillance, some ready/on-call attack helo support, and good C3, it is easily handle-able, even under the conditions which are best for the Iranians.

      • Yes. But I wasn’t talking of boat against boat actions. The definition, or should that be accepted meaning?, of a swarm attack is many small boats swarming around a naval vessel in the escort classes (corvette and up).

  5. Getting to the main thrust of Chuck’s point with this blog post, I’m cutting and pasting a previous post I made on the other topic about this (30mm Over 57mm?) here at Chuck’s:

    “Since the DDG-1000 class is truncated to only 3 ships, this, by itself, isn’t a huge impact on the Mk.110 program, but with the truncating of the LCS as well, this article begs another question: how sustainable is the Mk. 110 gun program?

    Originally, there were to be 32 DDG-1000s. It kept getting cut to, finally, 7, then 3, and now none of the 3 will have 57mms. So, the Mk.110 requirement went from 64 to Zero…

    The LCS was originally a 55-ship program, and it has been cut to a maximum of 32. So the requirement for number of systems has fallen here from 55 to a max of 32.

    The WMSL was going to be 9-ships, but 8 was probably always the best case scenario. With seven for sure, this cutter program looks to be the most-successful design of the three programs.

    By my count, the Mk.110 requirement (and original development cost planning) was based on around 127 systems. Now, it looks like, the true number is closer to 40. At what point does the 57mm gun program not look financially supportable? Even with adding 25 OPCs, the total number of systems in inventory will be half the original planning projections. I know the gun is supported overseas as well, but if I recall, there was a US production line set up in KY or TN just to build the US guns. I’m thinking the per-gun cost is going to rise steeply, as is the ammunition cost due to lower volume of use with half the projected systems.”

    Now, there’s some talk of putting 76mm systems on some of the LCSes. These combined factors may be the death knell for the Mk.110. Since the LCSes are looking at the 76mm, and DDG-1000 & LCSes (and some Amphibs) carry the 30mm, the choice would be between those two caliber systems. The question then becomes, “do you need a smaller caliber or a bigger caliber?” If smaller is the answer, why choose the 30mm (a new caliber and unfamiliar system) over the 25mm Mk.38?

    I was never a huge fan of the 57mm, but I grew to like it due to certain features. Looks like, in the end, not enough people in the right places came to like it…

    • Maybe I’ll get off my butt and do the outline of ordnance in the RCS/CG from 1790 to the present. It runs in cycles of real need and cost rather than what is the right system.

      Frankly, the Coast Guard does not have a mind for ordnance.

  6. “how hard would it be to do a armed UMV(unmanned maritime vehicle) for a kamikaze run like what happened to the Cole.”

    The Cole Incident resulted from complacency as much of the lack of ordnance or picket boats. A watching enemy usually wins these types of things. Even the VC learned how to take out helicopters. They all watch and study.

    • I apologize for getting off-topic, but this picture makes me think of a proposal I once suggested many, many moons ago when there was some mild clamor for an amphibious fire support ship to replace the NGFS capacity being lost by the decommissioning of the BBs. (A dedicated NGFS ship was one tangent being suggested, as it wouldn’t be called away from its key role by other duties.)

      I suggested a ship with modernized auto-loading guns similar to the 6″/47DP mounts of the Worcester class. Negating the fuze-setting equipment and functioning (since there is no AA requirement), and borrowing the autoloading technology base of the autoloading 5″ naval mounts of the 70s-90s (the most modern at that time) would (hopefully) have dealt with the functioning problems the Worcesters had with the 1940s-era mounts. Change caliber from 6″ to 155mm for NATO and US projectile commonality, and utilize combustable-case technology from the Abrams’ 120mm gun. Finally, fire control system modernized to utilize MRSI fire mode (the best reason for rapid fire with broad elevation range of these mounts).

      NGFS analysis from Korea showed the Worcester’s twelve 6″ autoloading guns had greater “impact” from a fixed bombardment period than an Iowa-class BB. Did I think 4 guns in 2 updated mounts would be that good? No, but it’s better than 1 or 2 DDGs with single 5″ers… (Combined with my other concept – 2 navalized MLRS launchers – the ship would have had some punch though.)

      Again, sorry for wandering.

      • My research has always suggested that one modern automatic naval gun equals one battery of conventional field artillery (6/8 guns). You can get similar weight of fires from a mount if you use two semi-automatic guns other than one automatic gun. I think both types of ammunition have their pro’s and cons. Though there are considerations such as HERO when it comes to producing ammunition for use in the field and at sea. Naval systems have obvious logistical advantages over land based systems when it comes to weight of fire. This can be coupled with the high utility of modern PGM to produce a system with huge flexibility.

        One of the main advantages of VLS is that they free deck for’ard so it easy to accommodate two mounts at both A and B in a small (relative term!) ship. Compare this to LCS,

        (Yes they 3in mounts but 5in could be easily accommodated. PGM are available for 3in anyway. And 3in trump LCS’s pitiful 57mm for littoral combat! Note 35mm on the hangar roof. )

  7. This from a USNI post quoting the Pentagon’s Director, Operational Test & Evaluation 2014 Annual Report (http://blog.usni.org/2015/01/22/remember-what-we-are-rewarding-with-lcs-to-ff), “The ship’s Mk 110 57 mm gun system performed reliably during operational testing, and the ship was able to demonstrate the core capability for self-defense against a small boat in two valid trials. The Navy attempted to collect additional data from swarm presentations, but the data were invalid. The 57 mm gun failed to achieve a mission kill during one swarm presentation, and the target killed by the 57 mm gun during a second swarm presentation had previously been engaged by 30 mm guns.”

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