June 11, 2023

Warship Taxonomies

The discussion on my recent post on Cruiser-Killers largely revolved around the question of what a battlecruiser was and how we would define that. But that in turn raises the question of how we classify warships in the first place, which seems worth taking a closer look at.

Two frigates pass each other

The most fundamental lesson of all warship taxonomies is that they are inherently messy things. Most of us here are nerds, with the nerd's compulsion to create neat, orderly classification schemes. Unfortunately, what we call warships today is the result of 150 years of evolution, with ships labeled on the basis of the nearest existing type, and old names sometimes brought back for new types. Any nice, clean scheme we come up with is likely to run into at least a few messy counterexamples, even before we get into the mess created by the fact that different nations describe their warships differently, and can't always agree on what to call them.

The distant roots of our system go back to the days of sail, when warships broadly speaking differed in only one respect: their size, and thus the number of guns they carried.1 The Royal Navy responded by classifying ships into six different rates, from the largest first-rates to the small sixth-rates. In the early 17th century, this rating was based on complement, but in 1677, Samuel Pepys changed the system to be based on the number of guns. This endured with various tweaks for almost 200 years, until the growth of guns made it useless. In broad strokes, first (100+ guns) and second-rates (80-98 guns) were armed with 3 decks2 of guns and were used almost exclusively as flagships. The typical ship of the line was a third-rate with 2 decks and 74 guns, with fourth-rate two-deckers going as low as 50 guns. Below that were frigates with a single gun deck, either fifth-rate (32-44 guns) or sixth-rate (28 guns). Even smaller were so-called post-ships with 20-26 guns, which were unrated but still had to have a full Captain, and smaller vessels, which would rate only a Commander. Some of these were technically not even ships, a term that described a vessel with three square-rigged masts. In this category, you'd see brigs, with two square-rigged masts, and the barques and barquentines, which have some of their three masts rigged fore-and-aft.

Different sail plans

But all of this was quite complicated, and over time, ships tended to be talked about not by their rate but directly using the number of guns they carried, producing designations like HMS Victory, 104.3 But that method only worked so long as ship design was relatively stable, a presumption which rather dramatically failed in the mid-19th century. Even before the arrival of the ironclad, guns had started to grow, and gun numbers to fall. Victory fought at Trafalgar with 32-pdrs on her lowest deck, 24-pdrs on her main deck and 12-pdrs above. HMS Victoria, 121, the last of the wooden battleships, had slightly heavier 8" guns on her lowest two decks and 32-pdrs above. But she was followed only a year later by Warrior, 40, a ship of approximately the same size that traded armament for armor. Initially, Warrior was classified as a frigate, but it seemed slightly silly to lump the most powerful ship afloat with ships designed for missions away from the battlefleet, and the problem became even worse as guns continued to grow and new methods of mounting them were devised.

It was in this period that the roots of the current system were established. The big ships, intended to fight other large ships as part of a fleet, were called battleships. Ships designed to operate independently were called cruisers and subdivided based on size and power, the term cruiser having originated in the age of sail as a mission (independent cruising, generally to hunt enemy commerce) rather than a ship type. And below that were smaller ships that would enforce colonial power, usually classified as gunboats. As ships became more complex, the basic designs diverged more and more, the most visible example being the retention of sails aboard cruisers long after battleships had shed them. But this didn't change the fundamental fact that all of these ships were primarily armed with guns and expected to face guns as their main threat. And as new technologies began to add new dimensions to naval warfare, this system began to fray.

Early American destroyers

The torpedo was the first of these technologies, giving small ships a way to seriously threaten big ones. Small, fast ships were soon constructed to carry these weapons, and were appropriately dubbed "torpedo boats". These were then countered by slightly larger ships, known as "torpedo boat destroyers", soon shortened to "destroyers". Destroyers proved to have better performance in rough seas, and generally proved more effective at operating with the fleet, and as a result they soon took over the torpedo attack role as well. These became an important part of the fleet, but there was still a clear distinction between the various types.

By the dawn of the 20th century, the cruiser had also bifurcated, with armored cruisers the size of battleships and much smaller light cruisers that were intended to scout for the fleet and support destroyers. The introduction of the dreadnought type saw the armored cruiser evolve along with it into what we today call the battlecruiser. That term didn't enter use until 1912 or so, and before that the British referred to their ships as "dreadnought armored cruisers", while the Germans used the term "Grosse Kreuzer" to refer to both their dreadnought and pre-dreadnought ships.

Things became even more complicated during WWI, as the submarine announced its arrival on the scene by sinking a significant fraction of the British Merchant Marine. While the fleet's destroyers had added submarines to the list of torpedo platforms they were to protect the battleships from, a cheaper vessel would be adequate for defending slow merchant ships. The results were known by a number of names, the British choosing sloop, a name they had long used for vessels smaller than cruisers, while the Americans built slightly smaller ships they designated as Submarine Chasers or Patrol Craft of various types.

The Tribal class destroyer Zulu

Interwar, the situation was somewhat regularized by the naval treaties, which created firm categories that mostly captured the existing ships, and then quickly began to shape the world's fleets. The most notable result was the proliferation of 8" heavy cruisers, and later 6" light cruisers. The construction of so many ships to treaty limits probably gave an impression of greater rigidity to the category boundaries than would have existed without the treaties, although even then, there were exceptions. Most notably, the French and Italians spent much of the interwar period building ships that straddled the line between big destroyers and small cruisers. When the British first entered this category, they considered several options for new designations, including "cruiser-destroyer", "support destroyer", "corvette" and "frigate" although in the end, they were simply called destroyers and given the names of tribes instead of regular British destroyer names.

Things became even worse when the war broke out, bringing with it the need for vast fleets of anti-submarine escorts. The RN had continued to call its escorts "sloops" through the interwar years, but the type had been designed as warships, out of the reach of commercial builders. To speed production, simplified designs were prepared, and for reasons that are not entirely clear but probably have a great deal to do with Winston Churchill and a visit from the Good Idea Fairy, the smaller ones were called corvettes and the bigger ones frigates, bringing back terms from the age of sail. (The Americans, practical as always, designated their frigate-equivalents as "Destroyer Escorts", and classified the corvettes they received as "Patrol Gunboats".)4

Dido of the Leander class, a postwar frigate

This set the stage for the situation today. Postwar, the surface threat was greatly reduced, while the Soviets poured most of their effort into building a vast submarine fleet. With a third showing of the Battle of the Atlantic apparently in the offing, ASW escorts became increasingly important, and the frigate gained a permanent place in the world's navies. But it entered a world that was increasingly confused about what to call warships. The revolution in naval warfare that occurred during the 40s had brought the reign of the gun to an end, killing off the battleship and the traditional cruiser, leaving only the destroyer and its descendants standing after 1960.

This left the designation system a mess, with the terms "frigate", "destroyer" and "cruiser" all persisting to some degree or another, although used very differently in different navies at different points. In general, the term "cruiser" was used for ships larger than traditional destroyers, although the USN chose "frigate" for this category instead (owing in part to its retention of a number of modified WWII cruisers as missile platforms), drawing on the heritage of Constitution and her sisters, calling the smaller vessels "ocean escorts", a category that most other navies used "frigate" for. In 1975, they finally realized that this was confusing everyone and switched to more standard usage, but even after that, you had destroyers bigger than cruisers and frigates bigger than destroyers.

A destroyer without serious AAW capability and a cruiser built on the same hull

The RN originally attempted to draw a clear distinction between destroyers (multirole ships capable of fleet speed), frigates (single-role ships primarily for escort purposes, including anti-submarine, anti-air and aircraft direction) and sloops (multirole ships capable of less than fleet speed), although the sloop category was soon collapsed into frigates to help the RN meet its NATO commitment for number of frigates. Faster submarines also drove up the speed of ASW frigates to the point where they could keep up with the fleet. And then you get things like the Leander class, which was based on a fast ASW ship, but had reasonable multi-role capability, but was still designated as a frigate. The current standard, so far as there is one, is that destroyers have area defense SAMs and frigates don't, while the cruiser is dying out. But even this isn't a hard-and-fast rule. All Japanese ships are usually referred to as destroyers,5 even the ones without area SAMs, and the US is currently procuring a class of frigates with the capability to carry every SAM in the arsenal. "Cruiser" seems to designate the highest-end air defense ships, but even this is slipping. The US is calling the Burke follow-on (which will mostly replace the Ticonderogas) DDG(X), while the Chinese are calling their big new Type 55 a destroyer, even though the USN classifies it as a cruiser. On the lower end, "corvette" is pretty much standard for ships smaller than frigates and usually distinguished by their lack of a helicopter and often any sort of medium air-defense weapon, although the USN has called theirs LCS in an attempt to disguise their utter pointlessness.

The basic lesson of all this complexity is pretty simple: modern warships, designed to face a multidimensional threat, defy easy categorization. There are some fairly safe assumptions one can make, but in practice, there's a lot of commonality between all major surface warships, whatever we may call them.

1 Yes, I am aware that this is a simplification, but it's a necessary one for the point I want to make.

2 This deserves a footnote of its own. For reasons beyond mortal understanding, guns on the weather deck (open to the air) weren't counted in this, so a 3-decker would have three decks of guns inside the hull plus some lighter guns topside, and so on for ships with fewer decks.

3 Since someone will probably bring it up if I don't, this is actually a very old system. The Greeks at one point classified ships by the number of rowers in each rank on each side, producing ships like quinquiremes/5s, which may have had either two rowers on each of the two upper oars and one on the lowest oar, or three on the upper and two on the lower. We later have references to much higher-numbered ships, but it's very unclear how anything over maybe a 10 worked, and it seems probable that higher-numbered ships didn't actually use the number of rowers specified.

4 Although they did use "patrol frigate" for a class of escorts built to civilian standards.

5 As discussed elsewhere, this is a different word from the one used for pre-1945 destroyers, and is more accurately translated as "escort".


  1. June 11, 2023muddywaters said...

    Amusing coincidence: current cruiser/destroyer/frigate by VLS cell count nearly matches old 3-decker/2-decker (normal ship-of-the-line)/1-decker (frigate and below) by gun count.

  2. June 12, 2023SurvivalBias said...

    Potential champion in the "fuck taxonomies I call it whatever the fuck I want" category: Russia officially classifies Typhoon-class subs as Heavy Submarine Strategic Missile Cruisers. The best I can tell all other Russian/Soviet boomers are the same but without "Heavy".

  3. June 13, 2023bean said...


    Interesting. Hadn't thought of that, but it's not far off.


    There's a reason I didn't touch Russian designations. Google translate renders the designation in the wiki article as "heavy missile strategic submarine", without any "cruiser". But it could also be a word meaning "long-ranged" or something like that.

  4. June 13, 2023Ian Argent said...

    "a great deal to do with Winston Churchill and a visit from the Good Idea Fairy" I thought W. Churchill was an avatar of the Good Idea Fairy in his own right, making this somewhat redundant

    In re the russian designation of the Typhoon - per this post "cruiser" could be translated as "long-ranged", at least in the meaning of "the cruiser mission"

  5. June 14, 2023Doctorpat said...

    All designed to make the army chaps feel that the question "what is a tank?" isn't so bad after all.

  6. June 14, 2023Jade Nekotenshi said...

    I wouldn't be surprised by the Russians using "cruising" or something like it as a descriptor, but this is distinct from "kreyser"/"крейсер", which is a direct loanword, and is, for example, used to describe the Kirov and Slava classes. (And also the Kynda and Kresta I classes. The US called Kresta II and Kara "cruisers", too, but Russia called them "large antisubmarine ship", even though the Karas were principally designed, AFAICT, for AAW.)

  7. June 15, 2023Ian Argent said...

    @Jade: if it's a loanword, then per my comment about the relationship between "cruiser" and "the cruising mission" I would say "yes, the russian term translates to 'long-ranged'"

    That the US termed them cruisers is probably tangled up in The Cruiser Gap politics...

  8. June 15, 2023Jade Nekotenshi said...

    Also, the Russians did seem to make some kind of distinction between "large X ship" and "X cruiser" - Kresta II was designated as "большой противолодочный корабль", while Moskva was designated as "противолодочный крейсер". (The Moskva class, not the Slava-class Moskva, which is "ракетный крейсер"). This doesn't even touch on the Kirov chaos - all I'll say about that is that the silhouette charts we had on Ramage designated Pyotr Velikiy as a CGN.

  9. June 15, 2023Hugh Fisher said...

    The Bilge Pumps podcast, Drachinifel and a couple of others talking about modern naval matters, suggested in the past that we could go back to the Age of Sail and just classify by the number of missiles on board. (Missiles capable in theory of being used against peer warships IIRC, RIM-116 style SAMs that would be MANPADS on land don't count.)

  10. June 16, 2023muddywaters said...

    It would make sense for the Russians in particular to care about their ships' fuel range, given that they're the physically largest country and have a history of that being an issue, but that doesn't look like how they assign the cruiser designation. If Wiki's values are correct (the Turkish straits are the one place where a treaty using standard displacement is still in force), Kresta IIs have more fuel than Kresta Is, though Karas do have unusually little.

  11. June 16, 2023redRover said...

    It seems like the confusion is/was maximized during the Cold War when the old gun based distinctions faded, but multi-mode systems had not yet reached sufficient development to really enable true multi-mission platforms. But going forward it seems like improved sensors and more modular weapons (primarily VLS) mean you have basically 'big multi-mission platforms (DDGs, CGs) of ~10K tons', more limited but still somewhat capable frigates of ~4-5K tons (FREMM, etc.), and then 'glorified patrol boats'.

    I'm sure the old names will stick around to some degree, especially given the service lives of some of these ships, but in practice it seems like multi-mode radar + VLS makes most platforms at least moderately surface and air-warfare capable, and the differentiators are 'radar power / size', 'cell count', and to a lesser degree 'speed/range/hull size'. ASW is more specialized, but even there it seems like most new classes blur the distinction.

  12. June 16, 2023ike said...

    Isn't there a minimum size for a ship to get fitted with a top shelf RADAR system. That sounds like a useful threshold.

  13. June 16, 2023bean said...

    @Hugh Fisher

    That runs headlong into the problem of ESSM. What do we do about the Nansens, which have 8 VLS cells, but normally carry 32 ESSMs? There's a big difference between various types of missiles past RAM, and a fair number of ships that carry a lot of the small ones. We could rate by theoretical ESSM capacity, although that raises other problems.


    Yes, but it's surprisingly small. See the Nansens again.

  14. June 17, 2023Alexander said...

    There are also non VLS missile mounts for anti-ship missiles, e.g. NSM, that would probably be worth including in a count of a warship's missiles. I'm not sure the difference in size between a ESSM and a SM-3 (or even the hypersonic missiles the Zumwalts might get) necessarily breaks the system, since age of sail warships varied in the weight of their guns as well as their number. On the other hand, Bean's point about the increasing size of breach loading guns causing problems for the historical system is noted.

    How would you handle heavier missiles carried aboard for use by a ship's helicopter? Exocet or Kh-35 would presumably be counted if intended to be launched from the ship, but if carried for use from a helicopter I could imagine them not being included. This despite the advantages of increased effective range and attack from a different axis that helicopter carried missiles bring.

  15. June 17, 2023bean said...

    since age of sail warships varied in the weight of their guns as well as their number

    The analogy doesn't quite work because under that system, the weight of a ship's guns was pretty predictable from their number. AFAIK, nobody ever built a frigate the size of a 38, and armed it with 16 really heavy guns. Likewise, there was nothing the size of a 74 that they made into a 120 with much lighter guns. There are reasons for that (the interplay of size and load-carrying capacity) but it was very different from what we're dealing with now.

  16. June 17, 2023Hugh Fisher said...

    Counting the missiles is a first step, a rough guide. The Age of Sail USS Essex had a significantly different type of gun armament (carronades instead of long guns) to other frigates of the same class, but it is still useful to know that she was a 5th Rate.

    @Alexander yes non-VLS missiles count if the ship can fire them. (Otherwise a Kirov or Slava wouldn't include its primary anti-ship armament!) But I wouldn't count helicopter missiles, those are more like the torpedoes carried by small boats on some dreadnought era warships. The helicopter is more likely to be absent for reasons other than mechanical failure/damage, the helicopter may be unable to fly in conditions that don't stop the rest of the ship, and the helicopter being shot down wouldn't normally be considered as damage to the ship.

    @bean yes there are different types of missiles. Comparing say a P-700 Shipwreck to an Aster-15 it has more value against an aircraft carrier or amphib, not so much against a patrol boat, and none against an aircraft. In the end though you only get one shot from each missile, you can only hit one ship or one aircraft.

    The ESSM is tricky, but I would say that a double/quad pack VLS missile is too small to be general purpose. If say an Arleigh Burke loaded every VLS with SM-6, that might not be considered ideal but the ship could still be reasonably confident engaging anything she encountered. I doubt that any Burke commander would load up mostly or entirely with ESSM if they weren't sure what might be out there.

    No doubt as missiles get smaller and more deadly this will change, but for now I think a VLS counts as 1, not 4.

  17. June 17, 2023bean said...

    The ESSM is tricky, but I would say that a double/quad pack VLS missile is too small to be general purpose.

    This is the bit I just can't get behind. Sure, that's a good argument for RAM, but the current ESSM has a range similar to a lot of the Terrier family, or the RIM-66B. And I know that in at least some games, all-ESSM tends to win battles simply because of how many quite decent shots you get.

    There's also the issue of counting the Mk 48 VLS, which is designed for Sea Sparrow/ESSM. Cells are significantly smaller than the Mk 41.

  18. June 17, 2023Brendan Richardson said...

    Of course, sci-fi authors love their fantasy ship classifications, but sometimes they get a little too attached to their "WWII In Space!" allegory and go overboard. (I'm looking at you, Starfire.) "Fast battleships" and the light/heavy cruiser distinction showing up where they have no business being...ugh.

  19. June 17, 2023Garrett said...

    Funny. Under the rating system of the Royal Navel, the USS Iowa, was at-best a 3rd rate ship based on gun count. Unless you want to try and count each barrel of the CWIS system separately or something. And yet it could wipe the floor with a Napoleonic Navy. Assuming you could get enough of a radar signature on the wooden ships to target effectively.

  20. June 17, 2023Alexander said...

    @bean "nobody ever built a frigate the size of a 38, and armed it with 16 really heavy guns"

    Well, as you said in the main post, Warrior is a little like that, with it's heavy smoothbores making it much better armed than a traditional frigate with a similar number of guns. Of course, warrior was the start of the old system breaking down, so point taken.

    @Garrett I expect the complete absence of radar (or ammunition) wouldn't stop any dreadnought battleship turning Napoleonic era vessels into kindling. For that matter, I expect RMS Queen Mary would take a long time to disable with round shot.

  21. June 17, 2023Eric Rall said...

    Under the rating system of the Royal Navel, the USS Iowa, was at-best a 3rd rate ship based on gun count. Unless you want to try and count each barrel of the CWIS system separately or something.

    We can probably fix this by keeping in mind that the rating were based on nominal gun count, which might vary from actual gun count at any given time. As I understand it, the rated nominal count usually corresponded to the weapon loadout the designers had in mind or to the typical armament a ship of that size would traditionally carry, but for any given mission the ship might be armed with more, lighter guns (or carronades instead of long cannons, to maximize close-in firepower at the expense of range) or fewer, heavier guns. While Iowa's WW2 armament is indeed pretty much what her designers intended and in line with what you'd expect on a ~50kT fast battleship of that era, we could probably abuse the nominal vs actual gun count distinction a bit to adjust Iowa's nominal gun count upwards to account for her main armament being just a little bit heavier than you'd expect to see on a first-rate ship of the line.

    To get a quick-and-dirty scaling factor for "normal" gun size, I compared the 1741 French frigate Médée (claimed by Wikipedia to be the one of the first true frigates) to HMS Victory. The former was 380 French tons, while the latter was 3500 long tons (call it about 10x as big, although Ancien Regime French measurements were such an ungodly mess on top of Wikipedia's ship stats being fairly inconsistent that this is only a vague guesstimate). Médée's main armament was 8-pounders, while Victory's heaviest guns were 32-pounders, giving us a rough scaling factor of 10x the displacement yielding 4x the gun size.

    Iowa is about 14x the displacement of Victory, so her biggest guns "should" be about 4^log(14) = 4.9x as big as Victory's. This gives about 160 lbs for Iowa's nominal main guns (corresponding to Victory's 32-pounder main gundeck long guns) and 60 lbs for Iowa's nominal secondary armament (corresponding to Victory's 12-pounder quarterdeck guns).

    The latter is actually pretty close, as Iowa's Mark 12 5" guns fire 55 lbs shells. The former is way off, as Iowa's main guns were designed to fire 2240 lbs shells and actual deployed ammo ranged from 1900 to 2800 lbs. Using the middle figure, Iowa's nine actual main guns are equivalent in throw weight to a total of 126 nominal guns, giving her a total nominal gun count of 146.

  22. June 18, 2023AlexT said...

    The analogy doesn’t quite work because under that system, the weight of a ship’s guns was pretty predictable from their number.

    Sure, and isn't this the case with missiles too? If a modern ship has 120 VLS tubes, is there any doubt that it will have at least some (probably a lot of) strike-length ones, a hefty radar and serious helo capability? Whereas if she has 8 tubes (size unspecified) wouldn't it be safe to assume RAM or ESSM at most, token radar and maybe a landing pad?

  23. June 18, 2023Alexander said...

    With eight missiles, you might well be looking at a missile boat, with essentially no air defence armament or landing pad, and all the missiles are surface to surface ones intended for anti-ship purposes. Something like a Skjold class. Alternatively it could be a corvette with no SAMs (like a Visby), or they aren't counting its RAM armament, as Hugh initially suggested, in which case you could be looking at an under armed frigate, like the F125. That's a big difference in displacement (and capability) between the larger and smaller "8 tube" ships. Maybe you should exclude anything without a helicopter hanger from this system at least?

  24. June 18, 2023Jade Nekotenshi said...

    The no-hangar filter, though, notches out Arleigh Burkes, at least prior to DDG-78, as well as the Japanese Kongo class. Though frankly, the decision to omit the hangar on what was otherwise an 8000-ton ship with 90-96 VLS plus Harpoons (8 as built, but IIRC there's space enough to mount 16 in a crunch) was kind of weird. And they do have a flight deck.

    Maybe exclude anything that has no hangar unless it has >=32 missile tubes?

  25. June 18, 2023bean said...


    Weren't you paying attention last week. The fire-control system was optical-first, and a wooden battle fleet would be easy. Close to about 2,000 yards, and fire one round WP at each ship.


    The issue with Warrior is that nobody ever tried to shove her into the traditional classification. It was obvious that a 40-gun ironclad was very different from a 40-gun wooden frigate, regardless of anything else that might be going on.

    We can probably fix this by keeping in mind that the rating were based on nominal gun count, which might vary from actual gun count at any given time.

    While actual gun count did vary from nominal, the nominal number wasn't just a mathematical abstraction. Yes, you might have a few extra carronades or whatever, but the actual count was fairly close. Instead of trying to scale gun sizes, we could just use weight of broadside or something.

    Whereas if she has 8 tubes (size unspecified) wouldn’t it be safe to assume RAM or ESSM at most, token radar and maybe a landing pad?

    This is a perfect illustration of the problems with the system. The Nansens are 8-tube under the straightforward system, and have Aegis (their SPY-1 is smaller than normal, but it's still Aegis) and a hanger for a helo. I wouldn't want to tangle with one if I had to get within 50 miles, unless I happened to be driving an oil tanker. But if we look at, say, the Dutch Karel Doorman class, we have a ship with 16 Mk 48 VLS cells (for a theoretical total of 32 ESSMs, although I think the Dutch have stuck with RIM-7) and other features quite similar to the Nansens, except for the lack of Aegis. But Nansen is an 8 and Doorman is a 16 (or a 16 and a 24 if we include their ASM launchers). The reason the old system worked is because I could say "HMS Sephora, 32" and it was safe to assume that we were talking about a frigate that was a reasonable match for other 32s. But Nansen, 8, is equal to or better than Doorman, 16 in almost all ways (with the possible exception of damage control).

    I also endorse Alexander's point, with one exception.

    Maybe you should exclude anything without a helicopter hanger from this system at least?

    That might be a problem for Arleigh Burke, 90.

  26. June 18, 2023bean said...

    Jade just beat me to the hangar point, but I can offer some clarity on the decision to omit it from the Burkes. The logic was that they were intended to be a low-cost design, the ships being replaced didn't have flight decks and the Navy thought it had enough hangar space on other classes that they didn't really need more. This changed when the Burkes became all of the escort force, hence the shift to hangars.

  27. June 18, 2023john.schilling@alumni.usc.edu said...

    "The analogy doesn’t quite work because under that system, the weight of a ship’s guns was pretty predictable from their number. AFAIK, nobody ever built a frigate the size of a 38, and armed it with 16 really heavy guns."

    Right, but I'm pretty sure nobody built a ship with an eight-cell VLS and loaded it with Standards. Or a ship with a 64-cell VLS and didn't put a whole lot of Standard and Tomahawk equivalents into most of the (occupied) cells.

    If we're going to do this by tube count, there's no reason to make it complicated. The old way counted guns and trusted people to understand which sizes made sense, we can do the same with VLS cells - A Mark 41 or a Mark 48 is a "tube"; so is a Sylver, or whatever the Russians call the tubes in their funky S-300 rotary launchers. We can trust people to put in the right mix of missiles, and not to e.g. build a ship with 64 Mark 48s. Deck tubes for SSMs/LACMs and magazine space for old-style twin-arm launchers count 1:1.

    Maybe we go 2:1 for the old Russian heavyweight SSMs, and 1:2 for anything that holds only a single Sea Sparrow class SAM.

    Really, though, I'd prefer to go with a mission-based classification. If it has oceanic range and can do area-defense AAW, over-the-horizon ASuW/land attack, and ASW beyond self-defense only, it's a "cruiser". Any two of those is a "destroyer", subtyped AAW or ASW depending on primary mission (does anyone still have ASuW-focused destroyers?) One mission, or two but slow and short-legged, is a "frigate", again subtyped. One mission and marginal blue-water capability, "corvette".

    We can if necessary come up with an MEL for each of those - and be very skeptical of anyone claiming serious ASW or ASuW capability without a helicopter.

  28. June 18, 2023bean said...

    You're not wrong that nobody builds a ship with less than 30 or so VLS cells and expects it to do broad area air defense. Spruance, 73, argues against the theory that anything above that does have area AD capability, but in fairness that was a while ago and seems unlikely to be repeated.

    Definitely think something mission-based is better, because words are more helpful than trying to find a 1D numerical classification given the weirdness of modern warships.

  29. June 18, 2023AlexT said...

    Tube count would work mostly as a quick reference, with the understanding that there are plenty of details that aren't included, but can be extrapolated assuming the ship designs make sense. Sailing ships also had weirdnesses, e.g. carronade ships with less capability than their high gun count would suggest.

    What it would add is resolution, compared to the current word-salad. Saying that there are a couple 16s in an area, but they're Nansens so they have aegis (btw wiki says they have 8 or 16 vls and 8 nsm, so they'd be either 16s or 24s) seems more accurate than "two frigates", which could equally well refer to Constellations or Type 22s.

  30. June 18, 2023Jade Nekotenshi said...

    I actually kinda like the mission-based classification that John's proposing here, possibly with tube count added as a qualifier or disambiguator.

    By this standard, I think you could call Arleigh Burke and clones cruisers, and the US doesn't have any destroyers (or arguably only Zumwalt). (And the Connies would be DDs, not FFs!)

  31. June 18, 2023Jade Nekotenshi said...

    Or, to revise, DDG-51 through DDG-77 are in fact DDGs, while 78 onward are CGs.

  32. June 19, 2023SurvivalBias said...

    Re Russian designations. I don't know what is the official definition of the term cruiser in the Russian Navy (or if there is one). But as Jade Nekotenshi said, it is a very specific loanword (крейсер) which is only ever used to refer to a class of warship and nothing else. [There's an adjective form "крейсерский" which is used in "cruising speed", but it's a different word, not the one used in the subs designation] Also, of the other two classes of nuclear subs, the guided missiles ones can be referred to as "cruisers", but attack submarines are not, even though afaiu they have similar range and can have mission profiles even more in line with the cruisers of old. So, I really doubt it's about range. By the feel of it, I'd guess "cruiser" was used in the Soviet era simply to designate high-end warships no matter the category, or something along these lines.

  33. June 19, 2023John Schilling said...

    @Jade Nekotenshi: I'd call all the Burkes "DDG(*)". The Flight I and Flight IIs for trying to claim ASW capability with just a towed array and VL-ASROC, no helicopters. And Flight III for "you would have been a cruiser, but you started out as an AAW destroyer and when you added the helicopters you took off the Harpoons and didn't deploy VL-LRASM".

    If the Flight III were a new design that someone wanted to call a "cruiser", I'd be OK with that but I'd quibble a bit about the ASuW mission with only land-attack Tomahawks that someone else is going to have to target.

  34. June 19, 2023Jade Nekotenshi said...

    I'd argue that Maritime Strike Tomahawk (which adds an imaging IR terminal seeker that has been demonstrated against moving targets at sea) plus SM-6 (which does have over-the-horizon ASuW capability) plus, AIUI, NSM launched from H-60s, would be enough to qualify, and that would qualify Flight III for sure, and maybe Flight IIa if the removal of the tail doesn't remove the ASW component. (I'd say it doesn't, because the typically-embarked helos are MH-60R, which do have all the ASW kit, and the combat systems can integrate with all that, since they're fundamentally still the same ones from Tico, which definitely covers all three mission areas.)

    And... Thinking about it, Zumwalt is a frigate. Mostly just land attack, with self-defense AAW and ASW.

  35. June 20, 2023bean said...

    Yeah, the three-cornered set of surface ship missions has become a square with the addition of land attack in the last 40 years. The Burkes cover at least 3 at all points, and all data we have points to the USN deciding on MST over VL-LRASM (which does appear to be under development for Australia after years of limbo) for long-range anti-shipping strike.

    Also seems worth pointing out that Zumwalt has SM-2 capability (can't remember on SM-6), which moves it a bit out of self-defense AA, even if that isn't the primary mission.

  36. June 20, 2023John Schilling said...

    The Zumwalt is its own thing, and if we're going with traditional classifications I'll suggest either "Monitor" or "Gunboat". It really does seem designed to fit the colonial-era gunboat role, even as we denounce all colonial ambitions.

    For anything less specialized than that, ASuW and land attack are going to overlap pretty strongly in most navies I think.

  37. June 20, 2023bean said...

    For anything less specialized than that, ASuW and land attack are going to overlap pretty strongly in most navies I think.

    Not sure where this is coming from. Anti-ship and land-attack missiles are pretty distinct. Yes, some modern anti-ship missiles do have backup GPS modes, but that always gets thrown out as an afterthought (also, a lot don't have the sort of range you get out of Tomahawk) while MST is the only case I can think of of a merger from the other side. The Flight IIA Burkes were excellent for land attack, but didn't have anything better than Standard or maybe VL-ASROC for ASuW. And on the other side, there are loads of ships which have ASMs but no serious land-attack capability.

  38. June 20, 2023John Schilling said...

    OK, "most navies" was an overstatement; most navies are basically coast defense forces. But for the serious blue-water navies, and looking only at destroyers and frigates launched in this century, I get:

    8 classes (PRC Type 055 and 052, French FREMM, ROK Sejong and Chungmugon Russia Gorshkov Gepard and Grigorovich) with both dedicated antiship and dedicated land-attack missiles

    3 classes (Australia Hobart, Japan Maya and Atago) that have antiship missiles and will get dedicated land-attack missiles as soon as Raytheon can build enough Tomahawks)

    3 classes (US Burke flight IIA and III, and Zumwalt) that have dedicated land-attack missiles and should get dedicated antiship missiles if Tomahawk Va or VL-LRASM become real

    8 classes (PRC Type 052, India Vishkapatnam Kolkata Shivalic and Talwar, ROK Incheon, UK Type 23 and Type 45) with dual-mode antiship/land attack missiles

    7 classes (Australia ANZAC, PRC Type 041 and 054, France Horizon, Italy FREMM and Horizon, Japan Mogami) with only antiship missiles

    Of the 7 in-development designs for which details are available, only France's FDI frigates will be limited to antiship capability. The rest (India Project 18 and Nilgiri, Russia Lider, UK type 26 and Type 31, US Constellation) all have dual-mode missiles.

    I think that points to a pretty strong trend of blue-water navies shifting to a combined antiship and land-attack capability.

    And from a classification standpoint, again I think we want to keep it simple and trust the operator to know what they are doing with the ordnance loadout. If a ship can reasonably expect to sink a major enemy warship well over the horizon, it counts as having ASuW capability and it's up to the operator whether they want to fill some of those tubes with land-attack missiles. If all you've got is a token eight Harpoon/NSM equivalents and no helicopter to find targets, that probably gets a "nice try, but no".

  39. June 21, 2023AlexT said...

    Isn't the target-type based classification pretty blurry, though? Meaning that, at least hardware-wise, ships that are capable vs. one domain ought to do well vs. all of them. E.g. helos that do ASW can also spot for ASuW, the same VLS tubes can launch Standard, VLASROC and naval Tomahawk, a hefty air-defense radar is just as useful for shooting down missiles in a peer fleet action etc.

    Sure, the ships' systems and software might not be designed, integrated and tested to work vs. all domains, especially on ships launched in the penny-pinching 90s, but can that keep happening now that competition is getting serious?

  40. June 21, 2023Alexander said...

    @AlexT ASW equipment (other than a helicopter) is pretty specialised. A towed array or an acoustically stealthy hull are only really useful in that role. Air defence and surface/land attack all revolve around missile combat, so there is more overlap, and a VLS based rating makes more sense, though clearly it would obscure some differences. If the Venturer frigates get a 32 cell VLS and multi-role Tomahawk or equivalent, it will be much more capable in the land attack role than the Darings (48 cell + eventually Sea Ceptor) which have a more sophisticated radar and are focused on AAW.

  41. June 21, 2023bean said...

    It's not just ASW. Serious AAW capability also involves a serious shipboard capability. Having VLASROC and Standard in your VLS is all very well, but they're pretty useless if you don't know where to aim them, and both require substantial systems to solve that problem. Yes, you could get someone else to send you that information, but that opens up a whole new set of problems. Tomahawk is the exception to this, because for that it is not expected for the ship to find its own targets.

  42. June 21, 2023redRover said...

    Razeed ships (https://en.wikipedia.org/wiki/Razee ) seem like a complication to the gun count in the age of sail, as they had essentially higher tier hulls and sailing ability with fewer guns.

    I don’t know offhand what the modern equivalent of that would be.

    Alternate thought on classification - would explosive throw weight with some adjustment for target type and/or speed of missile (to give greater weight to high speed low yield SAMs) be a modern broadside measure?

  43. June 21, 2023Alexander said...

    Absolutely. To go back to the comparison between the type 45 and 31, just compare the difference in the size of the masts on the two classes. You can literally see which one prioritises having a bigger radar with a larger field of view. And there will be less obvious differences within the ship to let the crew understand and act on all the data that SAMPSON generates.

    On the other hand, my bet is that there is a strong correlation between the quality of the radar and the number of VLS tubes. Or at least a more significant relationship than the VLS size and the ASW performance of the ship. I may be getting confused by British naming conventions, but I expect that it is more common for single mission "frigates" (using John's classification system) to more commonly be ASW focused, and ships with an area defence AAW role to be "destroyers" or "cruisers" because of the complementary nature of big radars and lots of missiles.

  44. June 22, 2023Jade Nekotenshi said...

    @Alexander I think I'd broadly agree with that, with the Type 45s being kind of the poster-child exception. (Though in theory SYLVER can launch Storm Shadow, but IIRC they're not actually configured to do so.)

    I'd call the Kirovs exceptions too, except that they're old relics from the days of dedicated launchers. It's just that on Pyotr Velikiy, the dedicated launchers are all one species of VLS or another, modulo the RBUs and guns.

    It also strikes me that using the target-set classification, Burkes wouldn't be the only ships getting switched around.

    For example, I'd be inclined to call Type 45 an FFG under that system, while Alvaro de Bazan (currently designated a frigate) would be a DDG or even CG.

    Oh, and I think there is one surface-warfare-focused destroyer left, that I'd be comfortable calling a destroyer, even if it is a 1970s design: the Sovremenyy class. SS-N-22 and SA-N-7 - I'd call that area defense, if somewhat limited, and anti-shipping-focused. You could maybe make a case for calling it a cruiser, except that IIRC there's no Russian helo capable of both ASW and missile targeting, and RBU-1000 plus 53cm torps does not make for any more than self-defense ASW.

  45. June 22, 2023bean said...

    I think the Sovremneys have the Russian SUBROC equivalent that has a 53 cm torpedo which fires an ASW missile. Which is a very weird thing, but it does exist. So they might fall into CG status.

  46. June 22, 2023John Schilling said...

    The Sovremennys don't have a towed array, or even a VDS, and they've only got one helicopter. If they're carrying a helicopter optimized for ASuW, they can't find targets for those weird SUBROCskis. And I wouldn't be at all surprised if the 533mm tubes aren't there as much for ASuW as ASW, given that missiles kind of suck at actually sinking ships. So, ASuW destroyer

    The Slavas still only have the one probably-ASuW helicopter, but they do have a towed array to go with the possible SUBROCskis, so they're at least marginally a cruiser.

    The Kirovs (being generous with the plural) have three helicopters, a towed array, and long-range ASW missiles, so they're definitely at least a cruiser. Arguably the combination of unlimited nuclear-powered range, significantly more tube-equivalents than anything else afloat, and an explicit sink-enemy-capital-ships mission means we should come up with a name for whatever is above a "cruiser".

  47. June 23, 2023Jade Nekotenshi said...

    USN pubs call them CGNs most of the time, but "CBGN" persists in a few places. "Large Cruiser" is a little underwhelming, but the shoe seems to fit.

  48. June 23, 2023redRover said...

    Would (launchable) missile volume be a good alternate measure of offensive capability, rather than just pure tube count? I.e., a MK 57 launcher would be 15m^3 of rating, and proportionately for other launchers.

    (Showing the math - https://en.m.wikipedia.org/wiki/Mark41VerticalLaunchingSystem A single cell is .71m wide, and presumably .71m square, with a cell length of 7.2m, and 4 cells to the launcher, so 4 * 0.71 * 0.71 * 7.2 = 14.52m^3 )

  49. June 23, 2023Ian Argent said...

    @redRover: So a later-flight Arleigh Burke carries ~360 megaliters of VLS capacity (assuming I can do the arithmetic properly)? (96 cells, 4 cells per launcher, 15 megaliters per launcher)

  50. June 23, 2023Hugh Fisher said...

    The Kirovs are BCGNs. Big, fast, heavily armed, not so great on the armour.

  51. June 23, 2023Hugh Fisher said...

    Two problems with warhead size and/or volume.

    First, both measures make old missiles seem more dangerous than new. The 1960s era Soviet missiles have bigger warheads and dimensions than the later, I doubt they are considered more effective.

    Secondly, the reason for counting missiles/tubes is that in modern naval warfare the number of shots is usually more important than the warhead.

    If you've got 4 missiles on board that's the absolute limit on how many ships or aircraft you can hit. Modern ships don't have armour, so there is only rarely an advantage to the monster missiles like the P-700. A small ship will usually be better off with 16 small missiles than 4 big ones.

    And volume is not a useful measure for missiles because they are not fractional. Like torpedo tubes on WW1/WW2 ships, you have to have a whole number. A Mk41 can fire one missile, so can a Mk48, BUT the Mk48 can also fire 4 small missiles. There's no point in adding an extra 2 litres to each of your Mk48 cells: you won't get an extra missile from it.

  52. June 24, 2023redRover said...

    @Hugh Fisher

    BUT the Mk48 can also fire 4 small missiles. There’s no point in adding an extra 2 litres to each of your Mk48 cells: you won’t get an extra missile from it.

    But that’s not strictly true. The longer VLS cells allow you to launch more capable missiles with longer range. Obviously an extra inch or two won’t make a huge difference, but going from the self-defense to strike length VLS is in fact a meaningful increase in capability. Like any single metric it’s of course imperfect, but volume correlates better to capability.

    First, both measures make old missiles seem more dangerous than new. The 1960s era Soviet missiles have bigger warheads and dimensions than the later, I doubt they are considered more effective.

    Agreed in part, though I think like most metrics it has to assume a certain level of technical equivalence.

  53. January 25, 2024Tony Zbaraschuk said...

    I thought W. Churchill was an avatar of the Good Idea Fairy in his own right

    One of the reasons that WC picked strong-willed people willing to argue him for his chiefs of staff (e.g., Sir Arthur Bryant) is that, as one of them phrased it, "he has about fifty ideas a day, of which only two are any d*mn good".) Churchill was certainly on very good terms with the Good Idea Fairy, but the Bad Idea Fairy, the Silly Idea Fairy, the Old Victorian Subaltern Ideas Fairy, and about eight others, all had standing dinner invitations... and they all dressed _exactly_ alike.

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