January 03, 2018

A Spotter's Guide to Modern Warships

Over the 70 years since the end of WW2, the nomenclature of warships has become very confused. This is for several reasons. The demise of the treaty structure removed the legal restrictions preventing categories merging. The minimum size of ship required for effective operations grew, while at the same time the need for numbers held down sizes on the top end. Different countries adopted different naming schemes for political or historical reasons, and classifications evolved over time. I’ll do my best to explain all of this, but it is of necessity an imperfect science. This list skews a bit towards what you'd see on the oceans today, or at least since the 80s, but it should be helpful in understanding what was going on since the 60s, or even earlier in combination with the previous list.

First, some definition of the weapons is necessary:

  • Guns: Typical modern naval guns run from 3 to 5". They are of limited use against low-performance aircraft and incoming missiles, but are often valuable for shore bombardment and firing shots across the bows of merchant ships to get their attention.
  • PD SAM (Point-Defense Surface-to-Air Missile): A PD SAM is designed to protect the ship it's mounted on, and maybe the ship next to it, against incoming anti-ship missiles or airplanes flying really low. It is not effective at protecting a group, or at shooting down aircraft at altitude.
  • MR SAM (Medium-range SAM): An MR SAM is an area-defense weapon. It's a threat to airplanes at significant altitude and range, and also has some capability against missiles.
  • LR SAM (Long-range SAM): A higher-powered variant of an MR SAM. More range, and probably a ballistic-missile defense capability in modern ships.
  • SSM (Surface-to-Surface Missile): A SSM is a weapon designed to kill other ships. There are two basic varieties. First, small, subsonic weapons designed to kill frigates. These are very common, but are unlikely to sink even a frigate outright. They'll badly wound a larger ship, but not kill it. Second, large, supersonic missiles designed to kill big ships. These are mostly Russian in origin, intended to be fired at US carriers.
  • ASW (Anti-Submarine Warfare) launcher: A weapon that fires depth charges ahead of or to the side of the ship. These are unguided and have relatively short range.
  • ASW torpedo: A small homing torpedo. Short-ranged, and usually has to be dropped pretty much right on top of the submarine to be effective.
  • ASW missile: A long-range ASW weapon, usually a missile fitted with a homing torpedo for a head.
  • CIWS (Close-In Weapons System): An automatic gun, usually 20-30 mm, with an attached radar. Intended to shoot down incoming SSMs autonomously.
  • Torpedo tube: A large tube for launching underwater weapons. Found mostly on submarines these days. Most common weapon is the heavy torpedo, useful against both surface ships and submarines. Some can fire SSMs, ASW missiles and cruise missiles, too.
  • Cruise missile: A land-attack missile, fired from a warship. Several hundred mile range, warhead ~1000 lbs. Can often be launched from modern ships equipped with MR or LR SAMs.
  • Helicopter: Probably the main weapon of many modern surface combatants. Capable of many roles: moving people and things around, hunting submarines, and patrolling for and attacking surface vessels.

Now, onto the ships:

  • Frigate:1 The most common type of modern surface warship. A vessel of 2,000-4,000 tons, equipped with 1-2 guns, some combination of ASW launchers, torpedoes, and ASW missiles, and a helicopter. May also carry SSMs, PD SAM systems and/or CIWS. Split between general-purpose surface warships, and specialized ASW escorts. 27-32 kts. Also called a destroyer or destroyer escort.
  • Destroyer: A slightly larger surface warship than a frigate. 3,000-8,000 tons, with 1-2 guns, CIWS and some combination of ASW weapons. Usually has an MR SAM, 4-8 SSMs and 1-2 helicopters. 30-36 kts. Normally intended as an anti-air escort, sometimes as a heavy ASW ship or an anti-surface platform. Current usage appears to be standardizing on ships with area-defense SAMs.
  • Cruiser: A heavier, larger version of the destroyer. 7,000-20,000 tons. 1-2 guns, CIWS, some ASW weapon(s) and LR SAM. SSMs and helicopters are common. Usually a heavy AAW escort, sometimes an anti-ship platform. 30-33 kts. Currently overlaps with the largest destroyers, which appear to be replacing them, as none have been built since the end of the Cold War.
  • Corvette: A smaller version of a frigate, usually without a helicopter. 500-2,000 tons. ASW weapons, 1-2 guns, and SSMs are common, some have PD SAM. Some specialize in ASW, although most are general-purpose. 30 kts.
  • Helicopter Cruiser: A ship that's the back half of a carrier welded to the front of a cruiser. 6,000-15,000 tons. Weapons can include MR SAM, Gun, CIWS and ASW weapons. 3-15 helicopters. 30 kts. Used to deploy large numbers of helicopters for ASW.
  • Helicopter/VTOL Carrier: A ship designed for carrying ASW helicopters and VTOL aircraft. 10,000-36,000 tons. Some are armed only for self-defense (PD SAM and CIWS) while others have MR or LR SAMs, ASW weapons and SSMs. 20-30 aircraft. 28-30 kts. Used for sea control and very light strike missions. Sometimes given misleading names like "helicopter destroyer", "aviation cruiser" or "through-deck command cruiser" for legal/political reasons.
  • Aircraft Carrier, Small: A ship that carries conventional airplanes to sea. Some left over from WW2, others new-built. 30,000-70,000 tons, 40-60 aircraft. Guns, CIWS, and PD SAM are common. 30-32 kts. Used for sea control, ASW, and strike missions.
  • Aircraft Carrier, Large: A very large ship that carries conventional aircraft to sea. Often nuclear powered. 70,000-100,000 tons, 90 aircraft. CIWS and PD SAM. 30 kts. Similar missions to small aircraft carriers, but more capable.
  • Submarine, early diesel: A submarine, designed for greater underwater performance than the submarine of WWII, inspired by German Type XXI. Some converted, others new-built. 1,000-2,500 tons, 6-8 torpedo tubes, sometimes deck guns. 13-18 kts submerged. Used for anti-ship missions.
  • Submarine, diesel: A submarine designed entirely for underwater operations. Limited mobility, but very stealthy. 1,200-3,000 tons, 6-10 torpedo tubes. 15-25 kts submerged. Used for anti-ship and anti-submarine missions.
  • Submarine, nuclear attack: A submarine capable of true underwater operation. Capable of sustaining high underwater speeds indefinitely, never has to snorkle. 3,500-9,000 tons. 4-8 torpedo tubes, some carry missiles. 25-45 kts submerged. Used for anti-ship and anti-submarine missions, some have land strike capability.
  • Submarine, guided missile: A submarine intended to attack ships with cruise missiles. Most nuclear-powered. 6,000-18,000 tons. 4-8 torpedo tubes, 8-24 cruise missiles. 23-33 kts submerged. Used for attacking heavy surface ships. Rare today.
  • Submarine, ballistic missile: A submarine armed with nuclear ballistic missiles. Very quiet, nuclear-powered. 8,000-25,000 tons. 4-6 torpedo tubes, 16-24 nuclear missiles. 20-25 kts submerged. Intended for destroying the world if necessary. So far, it hasn't been.
  • Minesweeper/Minehunter: A small, low-signature ship designed to deal with mines. 150-1,000 tons. 1 small gun, mine countermeasures equipment. 10-15 kts.
  • Torpedo Boat: A small, fast ship intended to fire torpedoes. 2 small guns, 4 torpedoes. 60-200 tons. 40-50 kts. For protecting coastal waters.
  • Missile Boat: A small ship intended for missile attack. 2-4 small guns, 4-8 missiles. 200-400 tons. 30-45 kts. Coastal defense.
  • Offshore Patrol Vessel (OPV): A ship intended for presence roles in coastal waters, by the Coast Guard or equivalent. 1-2 guns, may be fitted for but not with heavier weapons. 20-30 kts. Cheap, with a focus on seakeeping and high availability, and without the combat systems of proper warships. Larger ones have a helicopter.

As with the last list, I'm excluding amphibious ships and auxiliaries.


1 Note that until 1975, the USN used the word Frigate to mean a ship that is identified here as a cruiser. I was very confused when I first ran across a reference to a nuclear-powered frigate, being only familiar with the modern usage.

Comments

  1. January 05, 2018Andrew Hunter said...

    What do you think of the Kirovs? They're definitely bigger than modern cruisers, but I'm not sure if they really deserver their own BC classification. (Also, what do you think of them as ships?)

  2. January 05, 2018bean said...

    I don't like calling them battlecruisers, as they don't really fit the classical battlecruiser niche. As ships, they're kind of interesting. They were designed as flagships for the Soviet Bastion (SSBN protection) groups, which is a mission that more or less went away with the end of the Cold War. I'm not sure I see the general reason to build a big non-carrier ship like that. They were supposed to be under 'cruiser', but I may need to bump the max tonnage a bit.

  3. January 05, 2018John Schilling said...

    The Russians just call them "heavy nuclear-powered guided missile cruisers", but I'm fine with the colloquial definition. They're bigger than any cruiser that didn't get a 'B' in its abbreviation, designed to hunt down and destroy anything up to and including enemy capital ships by way of high sustained speed and the most powerful, longest-ranged type of ship-to-ship ordnance, and tough but without the pretense of impenetrable armor. That's the essence of a battlecruiser even if it is tasked with defensive missions Jackie Fisher wouldn't have appreciated. If we need to fit what is now a singular ship of a singular class into the historical classification scheme, BC is as good as anything.

    Whether it's a good design depends on two factors. First, can a salvo of twenty P-700 heavy anti-ship missiles penetrate the missile defenses of high-value targets, e.g. US carrier battle groups escorted by Aegis cruisers and destroyers? Second, is a Kirov at all survivable against the threats it is likely to face, e.g. a stand-off missile attack by a US carrier air wing? Since the first requires anti-ship missiles to trump missile defenses and the second requires missile defenses to trump anti-ship missiles, I'm skeptical. But there are some asymmetries that might favor the Russians, and in any event it may have been the best they could do at the time.

    At this time, when Russia is mostly at peace but would like to remind the world she still has a navy, Peter the Great is a large, impressive, and IMO beautiful power projection platform well suited to that role and so comparable to HMS Vanguard in 1950 or HMS Hood in 1920. Building ships for that role is extravagantly expensive, but if you already paid for it and didn't use it in the war you expected, you're going to keep it around looking big and impressive until it wears out.

  4. January 05, 2018bean said...

    I can see both sides of it. I'm a bit more of a nomenclature purist than you are, and I don't like resurrecting extinct terms. I'd probably call them Large Cruisers, which fits somewhat better.

    But there are some asymmetries that might favor the Russians, and in any event it may have been the best they could do at the time.

    We'll deal with this next Friday. I'm much less confident in the S-300 than I am in AEGIS/SM-2, but overall I think the greatest threat to them is probably torpedoes.

    Building ships for that role is extravagantly expensive, but if you already paid for it and didn't use it in the war you expected, you're going to keep it around looking big and impressive until it wears out.

    Agreed. The Kirovs do have enough power to be genuinely useful warships (unlike the Iowas) and they're good at the presence role, too.

  5. January 05, 2018John Schilling said...
    I'm a bit more of a nomenclature purist than you are, and I don't like resurrecting extinct terms.

    How do you feel about frigates, in their various incarnations from the least powerful to the most powerful surface combatants and everything in between including at least one period of nonexistence and resurrection?

  6. January 05, 2018bean said...

    How do you feel about frigates, in their various incarnations from the least powerful to the most powerful surface combatants and everything in between including at least one period of nonexistence and resurrection?

    Do I wish the British had thought of some other term in WWII? Yes. But I'm also not going to insist on an entirely idiosyncratic term when the modern usage is well-established and even marginally coherent. The pre-1975 USN usage was just irritating. On the other hand, there isn't a consensus on what to call the Kirovs. If every single reference book called them battlecruisers, then I wouldn't disagree. But that's not the case.

  7. January 05, 2018Andrew Hunter said...

    We could bring back "pocket battleship..."

  8. January 05, 2018bean said...

    The bit where we don't have any active battleships for the Kirovs to be pocket versions of would seem to argue against that plan.

  9. January 09, 2018Philistine said...

    @cassander: As small as they are, these ships would only be able to carry a handful of jets. Izumo in a hypothetical Sea Control Ship role has been projected to carry 10 F-35Bs; Dokdo (smaller, and optimized as a 'phib rather than a carrier) even less. So it doesn't matter so much if they only have room to spot 2-4 fixed-wing aircraft at a time for STO ops, as they would never launch more than that at once anyway.

  10. January 09, 2018bean said...

    @Philistine

    Cassander was commenting on my link I posted at Slate Star Codex, and so may not see your post. Because of the number of my links there that don't get comments, I usually don't set the comment mirroring up immediately.

Comments from SlateStarCodex:

    • dodrian says:

      Are there any VTOL Carriers in active or recent service with planes on them? Do they have catapults?

      I was under the impression that we’re going through a bit of a VTOL drought at the moment, with Harriers mostly retired, and F35 variants only slowly trickling out of the factories.

      • John Schilling says:

        The two Italian carriers, Garibaldi and Cavour, still operate AV-8B Harriers. Everybody else, as you note, got caught in the trap of “we’ll just keep our old Harriers flying until the F-35B enters service, which Lockheed promises will be Real Soon Now”. The UK, India, Spain, and Thailand all had carriers operating Harriers in the past decade, but all have given up on carrier aviation until the F-35B is really available.

        There are some US amphibious-warfare ships that also operate Harriers and/or F-35Bs, but if bean ever gets around to writing the spotters guide for naval auxiliaries he’ll explain why they aren’t properly classified as aircraft carriers.

        • bean says:

          About 90% right. The Indians are going to ski-jumping Mig-29s instead, and the Thais were never that serious about it. AIUI (and this comes from someone who worked on Chakri Naruebet), they bought the Harriers intending to run them out of parts, and then leave the game. Chakri Naruebet is more of a big OPV with a flight deck, anyway. She doesn’t have the combat systems of a true carrier, as she was intended to support anti smuggler/pirate helicopter operations, not ASW or strike missions.

          There are some US amphibious-warfare ships that also operate Harriers and/or F-35Bs, but if bean ever gets around to writing the spotters guide for naval auxiliaries he’ll explain why they aren’t properly classified as aircraft carriers.

          You people are never satisfied! History of amphibious warfare is creeping up the list, and will probably be followed by a spotter’s guide.

      • cassander says:

        John Schilling’s rundown is pretty thorough for current users. For future users, both the Japanese and South Koreans are considering operating aircraft from some of their amphibious assault ships/helicopter destroyers. And the australians have ships large enough to do so and considered the idea but seem to have rejected it for now. The turks are building a ship that’s supposed to be capable of doing so, but as far as I know they haven’t committed to buying any f-35bs yet.

        That said, and as bean notes, it’s important to distinguish between VTOL, STOVL and STOBAR operations. VTOL (vertical take off and landing) imposes pretty substantial reductions in aircraft payload and fuel capacity compared to STOVL (short take off and vertical landing) and STOBAR (short takeoff but arrested recovery). And STOVL operations will have worse sortie rates and bringback capabilities than STOBAR.

        • John Schilling says:

          Pure VTOL operation is I think mostly an air-show stunt at this point. If the ship is an aircraft carrier of any sort, it will almost certainly have either a ski jump or a catapult; if it has neither it is either a helicopter carrier or an amphibious-warfare vessel.

          If it’s one of the latter, there will be pictures of what it would look like if refitted with a ski jump, and articles about how the sneaky so-and-sos are trying to covertly build aircraft carriers and what’s their imperialist agenda anyway. Whether this is true is more of a political question than a technical one.

          • AlphaGamma says:

            Pure VTOL operation is I think mostly an air-show stunt at this point.

            Air-show stunt or possibly ferry flights. The Atlantic Conveyor carried Harriers and Sea Harriers to the Falklands, which took off vertically from an improvised flight deck on arrival in order to make the short ferry flight to the aircraft carriers.

            One Sea Harrier was also kept fuelled and armed on deck during the voyage south in order to be ready to take off (vertically) and defend the ship from Argentinean long-range reconnaissance aircraft. I imagine weapons load and endurance would have been extremely limited, but given that said reconnaissance aircraft were Boeing 707s might have still been useful.

          • cassander says:

            the Japanese maybe, and korean almost certainly, would be be pure VTOL afaik. The japanese ships don’t have ramps, but are at least big enough that might be modified. the korean ships are only 200m long and 18k tons displacement (smaller than the invincible class), just looking at them it seems like they’d have to give up at least one deck spot to add a ramp, even assuming that the ship is structurally capable

          • bean says:

            I got a chance to examine the flight deck of USS America in some detail a year and a half ago. There was no ramp, and yet they routinely operate STOVL harriers. It’s helpful, but not required.

          • John Schilling says:

            What do the LHAs expect to do operationally with their 4-6 Harriers? I can’t imagine an opposed landing in any significant threat environment being done without carrier support.

          • bean says:

            What do the LHAs expect to do operationally with their 4-6 Harriers? I can’t imagine an opposed landing in any significant threat environment being done without carrier support.

            Oh, obviously not. It’s about 50% institutional memory of Fletcher pulling out at Guadalcanal, and 50% having a few strike aircraft of their own on tap so they can get fast CAS when they want, not when the Navy bothers to give them some. I was just pointing out that if you want to operate a few F-35Bs, you can do it without a ski jump. Don’t get me wrong. I expect the median use to be the Japanese/Korean Helicopter Carrier showing up to an intervention (the next Libya), getting in the pictures, and going “Look, we’re helping”, while other people do the difficult bits. Serious strike capability will be limited to a handful of navies. The USN, RN, MN, and maybe the PLAN. The Russians can only play when Kuznetzov’s engines work, and the Indians may eventually join the party.

          • cassander says:

            @bean and John

            You can see videos of flight deck operations on LHDs. Most of the ones I’ve seen have the harriers taking off pretty far back, just ahead of the forward elevator, which means they need about 2/3s of the flight deck to take off, which is about 170 out of 260 meters. Both the Izumos and Dokdos lack the squared bow you see with US amphibs, which reduces the effective length they have available for takeoff. The Izumos are about 250m long, but the Dokdos are only about 200 to start with, only a hair shorter then the HMS invincible, which, even with a ski ramp, had to launch harriers down almost its entire length. And remember, it’s not just a question of having enough length for a takeoff roll. the larger the percentage of your deck you need to keep clear for takeoff rolls, the less room you have to move around other aircraft which will slow down your deck cycle and limit how many aircraft you can effectively carry.

            Now, maybe the F-35Bs will need a shorter take-off run than the harriers, and maybe there’s a sweet spot where a F-35B with a short takeoff roll can get off the deck with more payload than pure VTOL, but it seems like it would be a big sacrifice for either ship to try operating in non VTOL mode, even if it’s possible.

          • bean says:

            @cassander
            I’ll agree that neither ship is an ideal STOVL carrier, and your points about deck size are well-made. That said, I don’t think it’s as binary as you suggest. Yes, operating fully-loaded planes will mean that you can’t range more than a few at once. But you can either not load them fully or accept that you aren’t going to be launching a full alpha strike. If you want that, use CATOBAR. I’m pretty sure that short STOVL is still better than VTOL in payload terms, although I don’t have refs to back that up.

    • Nornagest says:

      Nitpicks: reduplicated “CIWS” in the frigate description, and you’ve got an extra zero in the tonnage figures for early diesel subs.

    • bean says:

      Said Achmiz kindly gave me the ability to give people accounts which will let them comment without my having to approve each one. If you want one (and I’d request you make sure you’re going to comment before asking), email me at battleshipbean at gmail with the username (no spaces, but you can change the displayed name) and password you want.

    • bean says:

      I’ve reposted Why the Carriers are not Doomed, Part 1
      Those of you who read the original will note this was originally written as Part 2. I swapped them because it worked better this way.

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