Your Nation's Warships, Batch 3

[The Kievan People]

The basic truism that you don't seek to fight your enemy at their strongest point is, well, true.

For the flack Sun Tsu gets gets in these threads for being obvious he would have something obvious to say about plans that boil down to: Line up billions of dollars worth of aircraft and/or submarines plus ballistic missiles and/or cruise missiles and ram them into the teeth of the hostile CBG at full force. Over and over until something useful is achieved or you have nothing left.

To sink a carrier protected by a fully operational battle group is hard. If it was not hard, no one would use carriers. Hard enough that making direct attacks on carrier battle groups the fulcrum of your defensive strategy is frankly a terrible choice, no different than making your first plan to overcome the Maginot line in a alt-history rp a bayonet charge. Which does not mean you should never do it either, you don't have the luxury of picking and choosing engagements and sometimes the most direct approach IS the best one, but the fact there is no one weird trick to sink carriers is not a cause for concern by itself.

A lot of people tend to assume a (bastardized) Soviet approach, get a lot of aircraft or a lot of SSGNs together with a lot of missiles and fire free, is the best anti-carrier tactic. And the question of defeating carriers boils down to what number of these in what combination do I need? Oft ignored is that the Soviet navy never sunk a carrier, or anything like a carrier, and really didn't have a lot of major naval combat experience at all. While they had a lot of interesting ideas it does not follow that they were always the best ideas. If you are trying to defeat a carrier battle group WWSR* do is not really the first question to ask, because their approach was never validated, and there are obvious problems with relying so heavily on cruise missiles.

*What Would Soviet Russia Do

[Velkanika]

The basic truism that you don't seek to fight your enemy at their strongest point is, well, true.

For the flack Sun Tsu gets gets in these threads for being obvious he would have something obvious to say about plans that boil down to: Line up billions of dollars worth of aircraft and/or submarines plus ballistic missiles and/or cruise missiles and ram them into the teeth of the hostile CBG at full force. Over and over until something useful is achieved or you have nothing left.

To sink a carrier protected by a fully operational battle group is hard. If it was not hard, no one would use carriers. Hard enough that making direct attacks on carrier battle groups the fulcrum of your defensive strategy is frankly a terrible choice, no different than making your first plan to overcome the Maginot line in a alt-history rp a bayonet charge. Which does not mean you should never do it either, you don't have the luxury of picking and choosing engagements and sometimes the most direct approach IS the best one, but the fact there is no one weird trick to sink carriers is not a cause for concern by itself.

A lot of people tend to assume a (bastardized) Soviet approach, get a lot of aircraft or a lot of SSGNs together with a lot of missiles and fire free, is the best anti-carrier tactic. And the question of defeating carriers boils down to what number of these in what combination do I need? Oft ignored is that the Soviet navy never sunk a carrier, or anything like a carrier, and really didn't have a lot of major naval combat experience at all. While they had a lot of interesting ideas it does not follow that they were always the best ideas. If you are trying to defeat a carrier battle group WWSR* do is not really the first question to ask, because their approach was never validated, and there are obvious problems with relying so heavily on cruise missiles.

*What Would Soviet Russia Do

Excellent point regarding the fact that the Soviets never actually sank a carrier. I've done a fair bit of thinking (and wargaming) of modern carrier air battles, and I gotta say it plays out a lot like the WWII ones did except attacking aircraft can fire from outside surface warship AAA/SAM coverage. In short, it means that carrier fighters are even more important than they were previously.

[The Technocratic Syndicalists]

I'm not even sure what you're advocating for anymore. You're just shooting more holes in your own plan.

A successful submarine attack more or less comes down to luck. Not in the "I hope everything in this plan happens as it's supposed to" but in the "Oh look the carrier happens to be wandering right by us!" How else is a submarine supposed to catch a carrier steaming along at 25+ knots? It certainly won't be able to catch up to it at tactical speed.

If the submarine isn't already where it needs to be, it won't be helped by your air attack. And if it is, it can't coordinate with an air attack because it's in the middle of an enemy carrier group. Your plan requires some magically precise timing and communication which is difficult enough with forces that can communicate directly and exponentially more complicated with forces that cannot.

A submarine operating alone has as good if not a better chance of sinking an enemy carrier than one tightly leashed to a carrier group. It allows the submarine commander to operate as he sees fit and he will almost undoubtedly have more knowledge of how to use his boat than a carrier group commander who worked his way up either the surface or air wing chain of command. This doesn't mean that the submarine and carrier group never communicate, it just means that such tight coordination constrains the submarine's strengths as a covert independent action platform.

Yeah I'm started to think the plan is a bit convoluted and requires excessively complex coordination between the submarine and your CSG and strike aircraft. I think what I'll end up trying to do is based on the hostile CSG's current course estimate where it's headed and then send a sub or multiple subs to ambush it along its path, preferably where the ocean is deep enough for the sub to make full use of its depth capability. The preferable ambush spot would be when the carrier is being replenished or when its exiting/leaving a port but depending on the scenario that might not be feasible (ie the enemy CSG is underway and steaming towards a friendly coast). After intercepting and launching a full salvo of torpedoes at the carrier, which in actuality would consist of launching torpedoes at whichever ship in the group has the largest acoustic signature (presumably the carrier), the Sub, already at an operating depth of at least several hundred feet (thus unable to use its photonic mast for target identification), would immediately dive as deep as possible to avoid detection and then run away. Ideally the submarine would be launching its torpedoes from the lowest possible depth that the launch system will still work which is again to decrease the risk of detection. Like you said it will more or less come down to luck but then again you ideally have multiple subs at multiple ambush points and a single torpedo hit is probably going to at least mission kill the carrier.

[Triplebaconation]

The carrier's hidden weakness - a single torpedo!

[The Akasha Colony]

Yeah I'm started to think the plan is a bit convoluted and requires excessively complex coordination between the submarine and your CSG and strike aircraft. I think what I'll end up trying to do is based on the hostile CSG's current course estimate where it's headed and then send a sub or multiple subs to ambush it along its path, preferably where the ocean is deep enough for the sub to make full use of its depth capability. The preferable ambush spot would be when the carrier is being replenished or when its exiting/leaving a port but depending on the scenario that might not be feasible (ie the enemy CSG is underway and steaming towards a friendly coast). After intercepting and launching a full salvo of torpedoes at the carrier, which in actuality would consist of launching torpedoes at whichever ship in the group has the largest acoustic signature (presumably the carrier), the Sub, already at an operating depth of at least several hundred feet (thus unable to use its photonic mast for target identification), would immediately dive as deep as possible to avoid detection and then run away. Ideally the submarine would be launching its torpedoes from the lowest possible depth that the launch system will still work which is again to decrease the risk of detection. Like you said it will more or less come down to luck but then again you ideally have multiple subs at multiple ambush points and a single torpedo hit is probably going to at least mission kill the carrier.

There is much more to acoustic signatures than magnitude. Identifying the carrier would probably be done by searching for its specific acoustic signature, regardless of whether it's the loudest. Otherwise simple WWII-era noisemakers could easily distract the torpedoes by simply making a lot of noise. A lot can be determined by analyzing blade frequency, shaft count, and the myriad other noises a surface ship makes and that's how ships are actually identified.

[Velkanika]

I'm not even sure what you're advocating for anymore. You're just shooting more holes in your own plan.

A successful submarine attack more or less comes down to luck. Not in the "I hope everything in this plan happens as it's supposed to" but in the "Oh look the carrier happens to be wandering right by us!" How else is a submarine supposed to catch a carrier steaming along at 25+ knots? It certainly won't be able to catch up to it at tactical speed.

If the submarine isn't already where it needs to be, it won't be helped by your air attack. And if it is, it can't coordinate with an air attack because it's in the middle of an enemy carrier group. Your plan requires some magically precise timing and communication which is difficult enough with forces that can communicate directly and exponentially more complicated with forces that cannot.

A submarine operating alone has as good if not a better chance of sinking an enemy carrier than one tightly leashed to a carrier group. It allows the submarine commander to operate as he sees fit and he will almost undoubtedly have more knowledge of how to use his boat than a carrier group commander who worked his way up either the surface or air wing chain of command. This doesn't mean that the submarine and carrier group never communicate, it just means that such tight coordination constrains the submarine's strengths as a covert independent action platform.

Yeah I'm started to think the plan is a bit convoluted and requires excessively complex coordination between the submarine and your CSG and strike aircraft. I think what I'll end up trying to do is based on the hostile CSG's current course estimate where it's headed and then send a sub or multiple subs to ambush it along its path, preferably where the ocean is deep enough for the sub to make full use of its depth capability. The preferable ambush spot would be when the carrier is being replenished or when its exiting/leaving a port but depending on the scenario that might not be feasible (ie the enemy CSG is underway and steaming towards a friendly coast). After intercepting and launching a full salvo of torpedoes at the carrier, which in actuality would consist of launching torpedoes at whichever ship in the group has the largest acoustic signature (presumably the carrier), the Sub, already at an operating depth of at least several hundred feet (thus unable to use its photonic mast for target identification), would immediately dive as deep as possible to avoid detection and then run away. Ideally the submarine would be launching its torpedoes from the lowest possible depth that the launch system will still work which is again to decrease the risk of detection. Like you said it will more or less come down to luck but then again you ideally have multiple subs at multiple ambush points and a single torpedo hit is probably going to at least mission kill the carrier.

Before you do any of that, how do you plan on finding out where the carrier will be and where it's going? You've got a firm plan for what to do once you find the task force, but what about everything leading up to it?

[The Technocratic Syndicalists]

The carrier's hidden weakness - a single torpedo!

I mean I'm assuming a single heavyweight torpedo exploding underneath the keel of a carrier is enough to do at least a significant amount of damage, if not outright sink it.

There is much more to acoustic signatures than magnitude. Identifying the carrier would probably be done by searching for its specific acoustic signature, regardless of whether it's the loudest. Otherwise simple WWII-era noisemakers could easily distract the torpedoes by simply making a lot of noise. A lot can be determined by analyzing blade frequency, shaft count, and the myriad other noises a surface ship makes and that's how ships are actually identified.

I mean Ideally you would have a comprehensive acoustic profile of the hostile ships involved which you've developed previously via underwater surveillance which would let your submarine (and by extension the torpedo as well) identify which ship is which. In that absence of a predetermined acoustic profile I'm assuming the carrier will have four screws while the escorts have only two each which would be the easiest giveaway along with the larger propeller size of the carrier which would I presume have an identifiable different acoustic signature compared to the smaller propellers used by the escorts.

Before you do any of that, how do you plan on finding out where the carrier will be and where it's going? You've got a firm plan for what to do once you find the task force, but what about everything leading up to it?

Most likely a reconnaissance aircraft, say a stealthy drone, using passive RF sensors to locate the carrier group via it's electromagnetic emissions like radar, GPS, radio, etc or maybe using optical/multispectral sensors to track the carriers from its wake. Basically something stealthy that won't immediately alert the CSG that it's being tracked.

You could also try using SIGINT/COMINT to intercept and decipher the carriers communications, if that's possible.

[Velkanika]

The carrier's hidden weakness - a single torpedo!

I mean I'm assuming a single heavyweight torpedo exploding underneath the keel of a carrier is enough to do at least a significant amount of damage, if not outright sink it.

There is much more to acoustic signatures than magnitude. Identifying the carrier would probably be done by searching for its specific acoustic signature, regardless of whether it's the loudest. Otherwise simple WWII-era noisemakers could easily distract the torpedoes by simply making a lot of noise. A lot can be determined by analyzing blade frequency, shaft count, and the myriad other noises a surface ship makes and that's how ships are actually identified.

I mean Ideally you would have a comprehensive acoustic profile of the hostile ships involved which you've developed previously via underwater surveillance which would let your submarine (and by extension the torpedo as well) identify which ship is which. In that absence of a predetermined acoustic profile I'm assuming the carrier will have four screws while the escorts have only two each which would be the easiest giveaway along with the larger propeller size of the carrier which would I presume have an identifiable different acoustic signature compared to the smaller propellers used by the escorts.

Before you do any of that, how do you plan on finding out where the carrier will be and where it's going? You've got a firm plan for what to do once you find the task force, but what about everything leading up to it?

Most likely a reconnaissance aircraft, say a stealthy drone, using passive RF sensors to locate the carrier group via it's electromagnetic emissions like radar, GPS, radio, etc or maybe using optical/multispectral sensors to track the carriers from its wake. Basically something stealthy that won't immediately alert the CSG that it's being tracked.

You could also try using SIGINT/COMINT to intercept and decipher the carriers communications, if that's possible.

It would take a couple heavyweight torpedoes to sink a modern USN supercarrier, those ships are tough and their damage control legendary.

That's a solid argument, but keep in mind that a sub would have to sit and listen to the various audio contacts for quite a while before it would be able to classify them. The carrier won't be immediately identifiable as such in all likelihood.

Elaborate on that. You've already demonstrated that you know how the terminal attack would work, but have you put a similar amount of effort into figuring out how to find the target? While we're at it, how would you do it using the assets you've got on your NS nation?

[The Technocratic Syndicalists]

It would take a couple heavyweight torpedoes to sink a modern USN supercarrier, those ships are tough and their damage control legendary.

That's a solid argument, but keep in mind that a sub would have to sit and listen to the various audio contacts for quite a while before it would be able to classify them. The carrier won't be immediately identifiable as such in all likelihood.

Elaborate on that. You've already demonstrated that you know how the terminal attack would work, but have you put a similar amount of effort into figuring out how to find the target? While we're at it, how would you do it using the assets you've got on your NS nation?

Ideally the carrier would be tracked from the minute it left port. In my region there are sort of two opposing factions that have formed kind of like warsaw pact vs NATO so there's basically a pseudo "cold war" going on and thus it there be an incentive to track enemy ship movements for if things suddenly get "hot". One option would be for a submarine to tail the CSG from a safe distance using passive sonar. The sub could also launch small, stealthy UAVs to aid in this task. Having a SOSUS type system using passive sonar sensors located underwater could also be an option with the SOSUS sensors clustered around strategic areas that a carrier would be likely to pass through. Another option which I mentioned earlier is say a high altitude, stealthy, RQ-180 type UAV with 24+ hour endurance which could track the CSG using the UAV's onboard passive sesnors without being detected. Something like say a hydrogen powered flying and/or blended wing which could cruise at 80+ kft equipped with say a hyperspectral imaging system and a passive ELINT/radiofrequency detection suite.

LEO Satellites aren't capable of tracking anything but they could be used for early warning purposes, a hostile CSG spotted by a SAR or optical satellite could then have a reconnaissance plane dispatched to track it, the CSG's general area being known from the satellite spot. This would be before things get "hot" so it's not like the other guy is going to be trying to actively shoot down my satellites. On the other hand a recon satellite placed in GEO would be able to theoretically continuously track any ship that enters its field of view. SIGINT satellites located in GEO could also locate the CSG from its electronic emissions.

The most desirable solution would be to use SIGINT/ELINT collected by an NSA type organization to intercept and decrypt enemy communications or files detailing the location and/or deployments of hostile forces which could include their carrier groups. .

[The Soodean Imperium]

So if I'm understanding all of this correctly, the "better" approach to stopping an approaching CVBG would be:
* independent SS(G)Ns patrolling the ocean in the hopes of stumbling across the carrier, its escorts, or its supply lines, throughout the entire process

* naval minefields deployed in key choke points along the route, to inflict attrition and to limit the speed at which the force can safely sprint

* harassing the battlegroup with probing attacks on its outermost escorts, which would be
- initiated from multiple angles, forcing the enemy to disperse their defenses and be weak at each point a la Sun Tzu
- supported by heavy jamming aircraft and airborne decoys like MALD and MALD-J
- focused on picking off the most isolated escorts, though if by chance the carrier is isolated it's a valid target
- used to assess the readiness and capability of the enemy fleet while also wearing it down and spreading it out

* one or more coordinated massed attacks once the CVBG has suffered enough attrition; this would also involve decoys, multiple attack angles, and heavy jamming

* and a return to smaller attacks, possibly using iron bombs, to mop up whatever is left

(for the purpose of simplicity I'm leaving out reconnaissance and intelligence, which would be going on throughout the process)

[Gallia-]

Stealth is a carrier's greatest weapon so IDK why you'd leave it out.

Soviet cruise missile spam was mostly about interdicting the relatively less defended convoys. Attacking carriers was a secondary mission.

[Theodosiya]

Putting CIWS on Corvette?

[The Soodean Imperium]

Stealth is a carrier's greatest weapon so IDK why you'd leave it out.

Because it's sufficiently important that it would crowd out the original topic, how to engage a CVBG assuming it's been located and it's being tracked. Obviously there would be an enormous of effort involved in filling out those assumptions in practice, but for the sake of specificity I'm currently focusing on the engagement part, as that seems to be an important area where my initial preconceptions were deeply mistaken.

Soviet cruise missile spam was mostly about interdicting the relatively less defended convoys. Attacking carriers was a secondary mission.

Noted. I really should put more effort into fleshing out my counter-convoy strategies, as given the geopolitics in my region, any interventionist powers interested in threatening my coast would have to work with long supply lines.

Putting CIWS on Corvette?

I'm aware of more corvettes that have CIWS than that don't.

For ships of that size a single mount is usually sufficient. Depending on role, you may have a 57-76mm dual-purpose gun forward and a 20-30mm CIWS mount aft.

[Theodosiya]

So, how much for a frigate as large as Sigmas or De Zeven Provinciens? Or Destroyers or Cruisers as large as Kirovs?

[The Akasha Colony]

So, how much for a frigate as large as Sigmas or De Zeven Provinciens? Or Destroyers or Cruisers as large as Kirovs?

We kinda just spent the last few pages talking about that...

One for smaller ships like corvettes. Two for ships in the broad size range of frigates or destroyers. This is also fine for cruisers too, but it depends how they're arranged. You really just need to make sure that at least one CIWS covers every arc, more than that isn't strictly necessary.

[Theodosiya]

Is there any way to effectively deploy corvette, frigates, destroyers, cruisers and av cruisers?

[The Akasha Colony]

Is there any way to effectively deploy corvette, frigates, destroyers, cruisers and av cruisers?

It usually helps to put them in the water in the general vicinity of your target.

I mean, the question itself as worded is incredibly vague and broad. It's basically "how do I use ships?," and dozens if not hundreds of books and essays have been written on the subject. It's like saying "how do I effectively deploy ground troops?"

[Velkanika]

Is there any way to effectively deploy corvette, frigates, destroyers, cruisers and av cruisers?

Questers has you covered. Read everything on that website and you should have a basic understanding of modern naval warfare.

Edit: Once you actually know the basics, refine that question down to something I can answer in less than 10,000 words.

[Theodosiya]

Should've said how to employ different ship classes in different fleets based on whether they're territorial or strike or littoral.

[The Akasha Colony]

Should've said how to employ different ship classes in different fleets based on whether they're territorial or strike or littoral.

It depends on what the ships are designed to do and what the fleet's objective is.

"Corvette," "frigate," "destroyer," and "cruiser" mean very little except for vague notions of size in a somewhat arbitrary hierarchy. It doesn't really define their role. You can have anti-aircraft frigates, which will be used differently from anti-submarine frigates, which will be used differently from general purpose frigates.

[Velkanika]

Should've said how to employ different ship classes in different fleets based on whether they're territorial or strike or littoral.

Right, well the first step is to determine what roles you need filled and then filling them with classes of warship. First off, you need to clearly define what a frigate, destroyer, and cruiser is and how those designations impact the ship you put into that category. Please note that these are my personal definitions for the Velkanikan Navy.

• I personally define frigates as light escort ships with an emphasis on ASW or general purpose warfare who almost never operate in wartime conditions outside of a larger group of warships. They lack the firepower and defenses to feasibly act alone, so they should be used only in battle groups of some kind.
• Destroyers are much more capable warships, and thus more expensive, and are often technically capable of independent operations in a pinch. That said, destroyers are usually found in larger task forces due to not being optimized for independent operations, and as such form the backbone of a modern naval formation's air defense and a considerable portion of its ASW firepower if they have helicopter facilities.
• Cruisers are designed to be able to operate completely by themselves, and often act as the flagships of various formations. They are universally extremely capable air defense and surface strike assets, and often have heavy ASW capabilities. Their size allows them to carry the most powerful systems and weapons in modern navies, which is what allows them to have the power to actually "cruise" the oceans alone. This also makes them some of the most powerful carrier escorts available, so every Carrier Battle Group will have at least one or two of these.

That covers three of the four principle surface combatants of a modern navy, with the fourth being aircraft carriers which I assume you already know enough about to use.

You also mentioned corvettes, and those ships are essentially half way between a Frigate and a Fast Attack Craft/Missile Boat. Corvettes are usually a missile boat with some air-defense or ASW capacity. They rarely have the crew facilities to operate very far from shore, so they're not particularly relevant to blue-water operations. That said, they are very good at operating close inshore where the size of a more capable warship is a hindrance and are usually quite a bit cheaper than a frigate. I personally use a ship that's somewhere between a missile boat and a corvette with Velkanika, but those are only really useful out to the extent of shore-based air cover and for special operations.

[Ormata]

OK, so I have another question.

What is a small (Crew of less than 100), long-range gunboat that is capable of operations on the high seas? In essence, what I am asking is...what is a class of vessel that is the equivalent of a floating oil drum with guns on it?

[United Earthlings]

If saturation attacks are not practical, how exactly does one go about attacking a well-defended carrier battlegroup?

That's a fair point. I would also have blue-water SSN patrols trying to attrit the enemy's supply lines, which would be very stretched if they're trying to put down an amphibious landing force. I just haven't put as much thought into the details there, as it's been pretty low on my list of things.

As others have already mentioned surprise {getting in the first salvo}, deception & attrition play a key role in executing a successful attack against a CBG.

However, hereto they have omitted a key deciding one, terrain limitations. When your enemy is forced to place their Carriers in geographical areas that greatly limit their capability to successfully maneuver at sea [the Mediterranean being a clear cut example], a necessity when a Carrier’s primary combat component {naval aviation} must act as an Air Base at Sea within range of similar land based air power, said Carrier(s) forfeit their well-defended nature to carry out a operational requirement.

To help with your thoughts of details, see this article and the one found below in reply to Kievan…

The basic truism that you don't seek to fight your enemy at their strongest point is, well, true.

For the flack Sun Tsu gets gets in these threads for being obvious he would have something obvious to say about plans that boil down to: Line up billions of dollars worth of aircraft and/or submarines plus ballistic missiles and/or cruise missiles and ram them into the teeth of the hostile CBG at full force. Over and over until something useful is achieved or you have nothing left.

To sink a carrier protected by a fully operational battle group is hard. If it was not hard, no one would use carriers. Hard enough that making direct attacks on carrier battle groups the fulcrum of your defensive strategy is frankly a terrible choice, no different than making your first plan to overcome the Maginot line in a alt-history rp a bayonet charge. Which does not mean you should never do it either, you don't have the luxury of picking and choosing engagements and sometimes the most direct approach IS the best one, but the fact there is no one weird trick to sink carriers is not a cause for concern by itself.

A lot of people tend to assume a (bastardized) Soviet approach, get a lot of aircraft or a lot of SSGNs together with a lot of missiles and fire free, is the best anti-carrier tactic. And the question of defeating carriers boils down to what number of these in what combination do I need? Oft ignored is that the Soviet navy never sunk a carrier, or anything like a carrier, and really didn't have a lot of major naval combat experience at all. While they had a lot of interesting ideas it does not follow that they were always the best ideas. If you are trying to defeat a carrier battle group WWSR* do is not really the first question to ask, because their approach was never validated, and there are obvious problems with relying so heavily on cruise missiles.

*What Would Soviet Russia Do

While I fully agree and endorse the one size approach doesn’t fit all, this article along with other published documents {specifically US Naval Strategy in 1970s & 1980s}, that there was in fact some validation to the WWSR* approach of the 1970s & 1980s as evidenced by the response of American naval strategy and of its evolution in the 1980s.

I also wish it noted that those who do pursue a WWSR* approach do so with the full knowledge of why the Soviets pursued what they did doctrinally and technologically with a clear view towards the political, militarily and geographic requirements and limitations imposed on the Soviet Union throughout its historical period. This knowledge would cut down on what Kievan rightly called the bastardized Soviet approach, which by its very nature by being bastardized is no longer the Soviet Approach and hence no longer applicable.

[Palmyrion]

Would missile CIWS work against small boats (ex. small yachts)?

[The Technocratic Syndicalists]

Would missile CIWS work against small boats (ex. small yachts)?

Yes, for example newer versions of the Phalanx have a FLIR targeting system (in addition to the radar) along with the ability for the gun to be remotely targeted from a crew station which lets the phalanx effectively engage surface ships. The Goalkeeper CIWS also has a secondary electro-optical targeting system which is similarly effective for this role. It's kind of a waste of ammo though, you're better of using your ships main 76/127/155mm/etc gun or using dedicated weapon stations like typhoon with a 25 or 30mm autocannon which are specifically intended to engage small surface ships.