Warship Types

Historically, the final arbiter of sea power. Descended from "battle ship of the line," which were the largest and most heavily gunned sailing warships (ex: H.M.S. Victory). After the end of the age of sail, the most heavily armed and protected warships were just called "battleships."

After the advent of H.M.S. Dreadnought, battleships were also called, generically, "dreadnoughts." (See below under Miscellaneous Terms for more about the Dreadnought.) This term basically just means a battleship armed with one size of big gun.

Battleships also carry the heaviest armor of all warships, generally intended to protect them from guns of the approximate size they themselves carried.

It was expected that in war, battleships would endeavor to meet their enemy in the sort of battle where one battle line would steam parallel to the enemy battle line and they would shoot it out until one battle line was sunk. This practically never happened (Tsushima and Jutland being the two times I can think of when it did, except that the Germans fled at Jutland and the battle was indecisive).

In WW II, BB's seldom fought each other, and in much smaller engagements when they did, usually just one or two battleships at a time. By then what is now called the 3rd generation of battleships were known as "fast battleships." (Dreadnought, and battleships like her armed with all 11" or 12" guns represented the first generation. The 2nd generation were the super Dreadnoughts with 13.5" to 16" guns, but speed still limited to the range of 20-24 knots.)

With the fast battleship, the battlecruiser and battleship types had merged. Battle line speeds were now 27 to 30 knots, about as fast as destroyers and cruisers could travel in a seaway. The battlecruiser H.M.S. Hood was really the precursor to all the fast battleships that followed. Improvement in power plants and the increase in size made high speed and heavy armor possible in the same ship. By treaty, the 3rd generation battleships built just before WW II were about 35,000 tons displacement. Read the introduction to my essay about the Treaty Battleships for more on this subject.

The rather rigid sort of battle as envisioned for the battle line led to the development of the battlecruiser. Battlecruisers, along with battleships, are classed as "capital ships." The battlecruiser was a ship about as large as a battleship and with battleship size guns, but protected against cruiser (6" or 8") gunfire, not against battleship gunfire. In the first and second generation ships, the weight that would have been devoted to additional armor was instead devoted to additional propulsion machinery. This allowed cruiser speeds (26 to 30 knots).

Since the battlecruiser could outshoot cruisers, it could sink enemy scout cruisers, and brush aside enemy cruiser screens to scout the enemy fleet's disposition. Of course, this only applied as long as the enemy did not also have battlecruisers. Since both sides built the type, they evolved toward the fast battleship. Protection against the enemy battlecruiser's big guns became important. This was driven home to the British in WW I at the Battle of Jutland, where they lost 3 CC's to enemy gunfire, which hastened the development of H.M.S. Hood. Hood was the first CC to carry the same thickness of armor as contemporary battleships. In order to combine heavy armor with high speed (given the efficiency of steam turbines at the time she was designed--during WW I), she was about 10,000 tons bigger than contemporary battleships (31,000t vs. 41,000 tons).

Only Russia operates modern, guided missile equipped battlecruisers today. Read the introduction to my essay about battlecruisers for more information about these fascinating ships.

The next biggest surface combatant after the capital ships. During the interwar years cruisers were limited by treaty to a maximum size of 10,000 tons standard displacement. Two types were defined by treaty: heavy cruisers (CA)--cruisers with 8 inch guns, and light cruisers (CL)--cruisers with 6 inch guns.

Cruisers had many roles. One was literally cruising the world; showing the flag, and representing overwhelming force that could be brought to bear far from home in colonial times. In wartime cruisers were to operate alone on the high seas to interdict enemy commerce; also to protect the battle line against enemy scout (light) cruisers. These were mostly heavy cruiser roles. Heavy cruisers are the smallest warships to which the term "heavy ships" is applied.

Light cruisers were primarily scout cruisers, intended to operate far in front of the battle line to find the enemy battle line and report its position. Also to drive off enemy destroyers that might attempt to torpedo friendly capital ships. Also to patrol lines of commerce against raiders. As they grew larger, their role tended to merge with that of the heavy cruisers.

Both wound up about 10,000 ton ships; the heavy cruisers carried 8 to 10 8" guns, the light cruisers carried 12 to 15 6" guns, and both carried a heavy battery of secondary and AA guns. Some cruisers also carried torpedo tubes. Both types usually had top speeds in excess of 30 knots. For more information, read the introduction to my essay "Heavy Cruisers of WW II."

Today, cruisers are primarily guided missile warships, ranging in size from around 7,000 to 10,000 tons. Only the world’s largest navies can afford to build and operate modern cruisers, principally the United States and Russia.

Historically called torpedo boat destroyers. Destroyers came about after the invention of the whitehead (self-propelled) torpedo. Suddenly there was a weapon that could be carried on a small, fast, cheap motorboat type of craft that could strike a capital ship underwater, bypassing all its armor protection (which at that time was designed to protect against gunfire above the surface, not threats below), and sink it.

Small fleets that could not afford capital ships built torpedo boats to defend against them. Naturally, the major naval powers that did have battleships moved to build small, fast, vessels that were larger and much better armed (with guns) than torpedo boats, and which were blue water ships that could travel with the fleet to defend it against torpedo boats.

Thus the torpedo boat destroyer came about. Later the name was shortened to just "destroyer." Soon, the destroyer itself was armed with torpedoes as well as guns. This allowed it to torpedo bigger enemy warships beyond the range of the small coastal torpedo boats. Torpedo boats were revived by all combatants in WW II--we called ours "PT" (Patrol Torpedo) boats, and John F. Kennedy commanded one. As it turned out, torpedo boats did little damage in any war, but destroyers became the jack of all trades among warships. Today, they are the largest surface combatants operated by most navies, ranging in size up to about 6,000 tons.

When submarines became practical, the destroyer was equipped with depth charges, SONAR, and other ASW weapons, and became their major enemy. Destroyers were used to protect convoys and larger warships against submarines. When aircraft became a major threat to ships, destroyers became AA ships as well. WW II destroyers ran around 2,000 tons, and were armed with a main battery of 4 to 6-4" to 5" guns, AA guns, torpedo tubes, and depth charges and other AS weapons. They were fast ships, generally capable of 30+ knots in calm seas.

A small destroyer, typically designed more for antisubmarine warfare than general purpose fleet defense. Along with frigates, DE's were the smallest blue water surface combatants. They were mass produced in great numbers during the Second World War, primarily as convoy escorts, but served in many capacities and in every theater. WW II DE's ran around 1,200 tons or smaller. DE’s carried a lighter main battery than destroyers (3-3" or 2-5" guns would be typical), plus AA guns, and perhaps a small battery of torpedo tubes. Their AS weapons fit was usually their strength. They were generally slower than fleet destroyers, with top speeds of 20-24 knots.

Another term for Destroyer Escort. Most European nations, including the British, called their DE's "frigates." Today, the U. S. Navy has abandoned the destroyer escort nomenclature, and also calls this class of warship frigates. Like all other classes of warships, frigates have grown in size. Today they are larger than WW II destroyers, often displacing up to 3,000 tons, and are usually capable of top speeds of 27 to 30 knots.

Submersible Ship. Modern submarines, if not nuclear powered, are sub-classed as "coastal" (short range) or "fleet" (oceanic patrol) types. Nuclear powered submarines are designated "SSN" if they are attack (anti-shipping) boats, and "SSBN" (boomers) if they carry ballistic missiles.

Anti-Aircraft Artillery.

Anti-Aircraft.

Towards the stern (rear) of the ship.

Anti-submarine.

Anti-submarine warfare

A column of armor that protects the ammunition hoist, and upon which the turret rotates.

The guns that can fire to one side of the ship. Also the act of firing all the guns on one side of the ship.

This is the U.S. Navy's Bureau of Ordinance.

Gun positions on warships which are protected on all sides by armor. The gun in a casemate fires through a slit or aperture in the armor.

The U.S. Navy's Bureau of Construction and Repair.

Battleships and battlecruisers, period. Literally, the ships that took the greatest investment of capital to build. In a sense analogous to capital in the financial sense (where capital gives clout or the ability to get things done), as the fleet's battleships and battlecruisers also represented the fleet's ability to get things done.

The number of people that serve on board a ship.

The place from which a warship is controlled in battle. On a "heavy ship" (like a battleship or cruiser) it is usually armored, unlike the bridge (which is not).

The weight of a ship, which is determined by the amount of water displaced by the ship.

English word which means to fear nothing. Should be in any good dictionary.

The H.M.S. Dreadnought of 1906 was a revolutionary ship, the first modern battleship. She incorporated many firsts: the fastest BB of the time, at 20 knots; the first all big gun battleship (10-12" main battery guns instead of a mix of heavy and medium bore guns); the first BB powered by steam turbine engines. All previous battleships immediately became obsolete after the advent of the Dreadnought. After Dreadnought, all similar battleships (with just one size of main battery gun) were also called, generically, "dreadnoughts."

Later the term became "super dreadnought," as main battery size increased to 13.5" guns, or larger. By WW II, main battery guns were typically 14", 15", or 16". The 11" gunned Scharnhorst and the 18" gunned Yamato classes were the exceptions.

The weight of a ship fully loaded with stores, fuel, and ammunition.

Her/His Majesty's Ship. All British warships are "H.M.S. Hood," etc.

A term used to refer to the largest surface combatants; includes battleships, battlecruisers, and heavy cruisers.

Discussed in detail in Norman Friedman's book U.S. Battleships. Basically, the zone (typically in thousands of yards) within which a ship's armor is intended to defeat enemy projectiles. So a certain BB might have armor designed to protect it against 14 inch shells from 15,000 yards to 22,000 yards. This means that closer than 15k yards, a 14 inch shell will probably have enough energy to penetrate the ship's side armor, but beyond 15k yards it does not--until the trajectory of the shell becomes so steep so that as it plunges out of the sky that it has enough energy to penetrate the armor on the deck. This happens at 22k yards in my example. At 20k or 21k yards, a shell may hit the deck, but the angle of impact and the armor on the armored deck are sufficient to prevent it from penetrating into the ship's vitals. But at 22,000 yards and farther, it can plunge through the deck armor. So my hypothetical BB is (relatively) protected from 14 inch gunfire between 15k and 22k yards: that is her immune zone. Read Friedman's books for more on this.

Nautical mile per hour. A nautical mile is somewhat longer than a statute (land) mile at 6080 feet, or 1,856.5m. Therefore, one knot is approximately 1.15 statute miles per hour

The space in a warship where ammunition and powder are stored.

The distance between a ship's center of gravity and the point through which the ship heels at small angles. The greater the metacentric height, the more stable the ship.

Displacement measured with the ship fully equipped, but carrying only one-third of its fuel.

Overall; As in the overall length of a ship.

Post to post; the length of a ship measured between perpendiculars. In practice, this is measured between the rudder post and the bow load waterline. It is a measurement that tends to ignore the form of the bow and stern.

Shaft horse power.

The American name for underwater sound detection equipment. The British name was Asdic. Sonar can be active (as when "pinging") or passive (listening only).

Defined by treaty as the measurement of a ship's displacement (weight) when she was ready for sea, but without reserve feed water and fuel. See my Treaty Battleships essay for a brief summary of the Washington Naval treaty.

The fixed structure of the ship above the hull.

The rotating part of an armored gun mount. Turrets are commonly seen on tanks and warships, and are designed to protect the guns and gun crews from enemy gunfire and the environment.

United States Ship. All US warships are properly "U.S.S. Alaska," etc

Water line; as in waterline length of a ship (which varies somewhat with displacement).