December 29, 2017

A Spotter's Guide to Warships of the World Wars

The terminology of ships during the first half of the 20th century is rather confusing, so to explain things, I've put together a pair of glossaries, one for each of the world wars. Each entry will give a sketch of the kind of ship you’d be likely to find under each description. These are not intended to be completely comprehensive, as I just don’t have time. I’m sure my nitpickers valued commenters will be able to come up with all of the cases I missed. I've also written a similar guide to contemporary ships.

  • Pre-dreadnought: A battleship built 1889-1905, designed to carry 4 12” guns and ~12 6” guns. Obsolete, but still in service in large numbers. A few may carry some bigger secondary guns in addition to the 6” guns. 12,000-16,000 tons. Speed 18 kts.
  • Semi-dreadnought: A battleship built 1900-1910, armed with 4 12” guns and a number of secondary guns bigger than 6”. Obsolete, and not built in numbers as large as the pre-dreadnoughts. 16,000 tons. Speed 18 kts.
  • Dreadnought: A battleship built 1905-1914, armed with a larger number of 12” guns (8-10). 10”-12” of armor. Most do not have secondaries bigger than 4”, although a few (mostly German) retain 6” secondaries. 18,000-20,000 tons. Speed 21 kts.
  • Super-dreadnought: A battleship built 1910-1920. Armed with guns bigger than 12” (8-12). Secondaries are 4-6”, and armor is increased to match growth in gun size. 22,000-30,000 tons. Speed 21-24 kts.
  • Armored Cruiser: A fast ship nearly the size of contemporary battleships, built 1890-1905. Intended for commerce protection or raiding and supporting fleet actions. Usually armed with a mix of 6” guns and larger guns, rarely above 10”. Lighter armor than battleships. Speed 21-23 kts.
  • Battlecruiser: The dreadnought equivalent of the armored cruiser, built 1905-1920. The same size as contemporary dreadnoughts, and carrying similar weapons. Early British ones are lightly armored (6-9”), while the Germans are lightly armed. Later British ones approximate a fast battleship. Speed 25-30 kts.
  • Light Cruiser: A ship armed with 5-8 4”-6” guns and torpedo tubes, and designed to serve as a scout, trade protector, and general fleet utility vessel. 2-3” of armor. Built 1905-1920. 4,000-5,000 tons. 29 kts.
  • Destroyer or Torpedo Boat: A small ship designed to launch torpedo attacks and fight other torpedo craft. 900-1100 tons. No armor. 4 4” or 88mm guns and torpedo tubes (3-12). Built 1910-1920. 33 kts.
  • Submarine: A surface ship that can temporarily submerge to evade detection. No, that isn’t a typo. A WWI submarine can be best thought of as a submersible surface ship. It could do about 15 kts on the surface and about 8 kts submerged, maybe a bit faster. 4-5 torpedo tubes, 1 gun. 500-800 tons.
  • Escort/Sloop/Minesweeper: An auxiliary warship for sweeping mines and patrolling or protecting convoys. 500-1200 tons, with a couple of medium guns and minesweeping equipment. May carry a few depth charges, or an explosive paravane system. 16-18 kts.
  • Seaplane Carrier: A ship, usually a converted merchantman, that carries seaplanes. Usually a dozen or so, but each one is unique. Most fly the planes off from the ship, then recover them from the water.
  • Armed Merchant Cruiser/Raider: A merchant ship, usually an ocean liner or a fast cargo ship, modified into a light warhip. Fast, long-range, with good seakeeping. Usually a few 6” guns. Speed varies greatly. Used for escort work and patrols, sometimes as a commerce raider.
  • Battleship, Pre-Treaty: See Super-Dreadnought, above. Anti-aircraft guns have been improved, and deck protection might have been increased as well.
  • Battleship, Treaty: A battleship built after 1930, under the auspices of the Washington Naval Treaty. 35,000 tons standard. Carries 8 or 9 guns of 14”, 15”, or 16”, with heavy anti-surface and anti-air secondaries. 12-14” of belt armor, good horizontal protection. 27 kts.
  • Battleship, Post-Treaty: A battleship built after 1936, not under the auspices of the Washington Naval Treaty. 40,000-70,000 tons. 8 or 9 guns of 15-18”. 12-16” of belt armor. 27-33 kts.
  • Aircraft Carrier: Either a conversion of a battleship or battlecruiser cancelled under the treaty, built in the mid-20s, or a new-build ship from 1930 on. 18,000-37,000 tons. Some carried up to 8” guns, but most have 5” guns and light AA guns. 50-90 aircraft, depending on configuration and loadout. Most are unarmored, but the British armored theirs (resulting in low aircraft loadouts.) 30-33 kts.
  • Carrier, Light: An austere carrier constructed quickly in wartime (1943-1945). 10,000-13,000 tons. Light AA guns only. 36 aircraft, unarmored. 25-31 kts.
  • Carrier, Escort: A slow, small carrier built to escort convoys and provide air support for amphibious landings. Built 1941-1945. Very light armament. 27-33 airplanes. 16-20 kts.
  • Large Cruiser/Light Battleship: A group of odd ships. Around 25,000 tons, armed with 11-13” guns. Built in the 30s and another batch in the mid-40s. Built for special reasons, and none were particularly successful. 30-33 kts.
  • Heavy Cruiser: A category created by the Washington Naval Treaty, 1925-1945. Most were 10,000 tons standard, rising to 15,000 tons for some wartime ships. Armed with 8” guns, usually 8 or 9. Lightly armored (3-6”), and often referred to as ‘tinclads’. 4-5” AA armament, sometimes torpedo tubes. 32 kts.
  • Light Cruiser: A creation of the London Treaty of 1930. 1932-1945. 7,000-11,000 tons, 8-15 6” guns. Otherwise, very similar to heavy cruisers in armor and secondary armament. 33 kts.
  • AA Cruiser: Another creation of the treaties. 1939-1945. 6,000 tons, and armed with 10-16 5” guns, the standard dual-purpose armament of contemporary battleships. 3” armor. Light AA guns, torpedo tubes. 32.5 kts.
  • Destroyer, WWI: A leftover destroyer from 1917-1920. Used primarily as an escort. 1090-1200 tons. As built: 4 4” guns, torpedo tubes, and depth charges, 34 kts. Many modified with more AA guns and ASW weapons, often with reduced speed and increased endurance.
  • Destroyer, Standard: A destroyer built 1927-1945, used for every purpose at sea, most notably ASW and AA screening. 1300-1700 tons. 4-5 DP (dual-purpose) guns of 4.7-5”. Light AA guns, 8-16 torpedo tubes, and depth charges. 37 kts.
  • Destroyer, Large: A destroyer built 1930-1945. 2000-2600 tons. A bigger, better-armed version of the standard destroyer, often with greatly increased range. 5-8 DP guns of 4.7-5”. More light AA guns, 8-16 torpedo tubes, and depth charges. 38 kts.
  • Destroyer Escort/Frigate: A mass-production escort built 1939-1945 as a war emergency escort ship for slow groups. 1000-1500 tons. 2-4 3”-5” AA or DP guns, 2-3 torpedoes, and extensive ASW armament. 20-28 kts.
  • Submarine, Small: Another submersible surface ship, small and relatively short-ranged, although the Germans used them throughout the Atlantic. Built 1930-1945. 600-700 tons, 4-5 torpedo tubes, 1 deck gun, light AA guns. 17 kts surfaced, 9 submerged.
  • Submarine, Large: A bigger, longer-ranged submarine. Built 1930-1945. 1300-1800 tons, 10 torpedo tubes, 1-2 deck guns, light AA guns. 15-21 kts surfaced, 9 submerged.
  • Corvette/Sub-chaser: A small ship designed as a light escort, hopefully for coastal waters, although many were employed in the Atlantic. Built 1940-1944, 800-950 tons. 1 3”-4” gun, light AA, depth charges/ASW weapons. 16 kts.
  • Minesweeper: A ship designed to remove mines by sweeping them up with cables towed alongside. Built 1937-1945, 800-950 tons. 1-2 3”-4” guns, light AA, some depth charges, minesweeping equipment. 17 kts.
  • Motor Torpedo Boat/PT Boat: A speedboat fitted to carry torpedoes. An excellent place to put dashing young officers who are not suitable for real work. Otherwise mostly useless. Built 1939-1945, 30-55 tons. 4 torpedo tubes, light AA guns. 39 kts.
  • Armed Merchant Cruiser/Raider: A merchant ship, usually an ocean liner or a fast cargo ship, modified into a light warhip. Fast, long-range, with good seakeeping. Usually a few 6” guns and AA armament. Speed varies greatly. Used for escort work and patrols, sometimes as a commerce raider.
  • Coastal Defense Ship: A ship designed to protect a country's coast. Built 1900-1940, 2000-6000 tons. 2-4 heavy guns, some lighter armament. 10-15 kts.
  • Monitor: A ship intended for coastal bombardment. Built 1915-1942. 6000-10000 tons. 1-2 guns of 9.2-18". Heavy underwater protection. 6-12 kts.

This is already quite a long list, so I'm going to leave auxiliaries and amphibious shipping off of it. I've discussed them both at some length elsewhere.


  1. December 29, 2017Rolf Andreassen said...

    Your WW2 list leaves off the existence of ancient pre-dreadnought ships for coast defence in some of the minor belligerents, for example "Eidsvold" and "Norge", the capital units of the Norwegian navy, such as it was. Built 1898 as part of the military buildup preparatory to demanding independence from Sweden, and considered reasonably powerful at the time. Incidentally I would love to see you do a post about this kind of ship.

  2. December 29, 2017bean said...

    It does. This is not meant to be a comprehensive list, and I had honestly not remembered those particular ships. I may throw in something about coastal defense ships when I get a chance to look over the issue more closely, and a column or two about them would be interesting. Probably not in the near future, though.

  3. December 31, 2017Johan Larson said...

    WWII frigates were purely for escort purposes?

  4. December 31, 2017bean said...

    Yes, at least in English nomenclature. The British needed a term for a new class of large escorts slower than destroyers. Later, it was used for everything except aircraft carriers.

  5. January 01, 2018Tony Zbaraschuk said...

    One might also mention monitors, which were basically one battleship turret on a raft, intended primarily for shore bombardment. (Did anyone but the British ever build one?)

  6. January 01, 2018Andrew Hunter said...

    Looking at the destroyer speeds--do you know what an Arleigh Burke or the like makes by comparison? Wikipedia just says "in excess of 30 kt" compared to the WW2-destoyer 39kt.

    I suppose it masses about the same as a light cruiser, of course.

  7. January 01, 2018bean said...

    This is a complicated question to answer. Back then, speeds were specified on a flat calm. The focus has shifted to speed in more realistic conditions, which slow ships. So in practice, they're of broadly similar speed. The Fletchers rarely got above 30-32 kts in practice, IIRC.

  8. January 02, 2018Andrew Hunter said...

    Ah, thanks. I'd been weirdly curious about this ever since I heard the story about "31-knot Burke."

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