Also called Dreadnoughts (name of the British ship that revolutionized the design of battleships at the start of the 20^th century). They started World War 2 at the top of the scale of warships. Five years later, all constructions were stopped and the battleships disappeared of modern battle fleet (except for some relics in the US Navy).

Between 1939 and 1945, a battleships weighted from 30 000 tons to 70 000 tons. She carried about 10 guns from 11 inches (German Scharnhorst) up to 18 inches (Japanese Yamato). The guns can shoot up to 30 kilometers away ! A battleship has an armor, whose thickness varies according to the part of the ship it must protect. It can be more than an halve meter for the vitals parts (the ammunition storage or the control tower), but is much reduced at the bow or the stern.

Between both World War, the range of guns and that of the fire control systems increased markedly. That has consequences on the way the shells landed on the aimed ships: it was no longer direct shots hitting the side of the ship, but indirect shots, falling from above. That made obsolescent all armored ships built during World War 1. They had to undergo costly modernization to allow them on the battlefield. A ship like the Hood, which had not been refitted, will fall victim of the sky falling shells of the Prinz Eugen and of the Bismarck.

A new element is the importance of the torpedo. Although the battleships themselves do not launch torpedoes, they must protect themselves from them. For that reason, a second hull was built around the first to make the torpedo explode before reaching the vital parts of the ships.

Until World War 2, speed was not a major requirement for battleships. The other ships had to adapt to the battleship, not the other way round. The rise of the aircraft carriers changed all that. They became escort ships for the carriers and only the battleships that could follow them could be used in the striking forces. The other ones, whatever other qualities they have, were relegated to fire-support missions during landing operations.

What really sealed the fate of the battleships, outside their cost, was the planes: whatever the armor, no ship can sustain a long time raining bombs and air torpedoes. The two largest World War 2 battleships (the Japanese Yamato and her sister-ship Musashi) fell victim of aerial attacks. Outside some French and British ones finished after the war, no new battleships will be laid down after 1943.

The aircraft carrier thanks its rise between the wars to ... arm limitation treaties ! Those treaties (Washington and London) dealt mainly with guns toting ships at a time when the abilities of the carriers were largely unknown. The treaties left the signing powers with lots of unfinished battleship hulls, whose only possible use was to build carriers.

A carrier is a landing runway with a ship below it. On the deck there is little room to install anything outside what is necessary for the planes themselves. It makes the carriers very vulnerable, with a large surface and little anti aircraft defense. The carrier must always operate with an escort that redress that imbalance against attacking aircraft's or incoming submarines and surface ships.

Below the landing decks, there are plane hangars. The communication between both happened through lifts, visible on photographs. It was usually inside the hangars that the life or death of an aircraft carriers was decided when she was hit: if the planes, the ammunitions or the gasoline went off, nothing could save the ship.

To start and land on a short runway, you need help from relative speed of the ship and the wind. To launch or receive planes, the carriers must sail against the wind, even if that was not the direction where the admiral wanted to lead the fleet. The carrier must be a speedy ship (around 30 knots).

When World War II broke out, the carriers were still in the shadow of the battleships. The British success at Taranto was the evidence of the importance of the new weapon: a handful of planes brought close enough by a carrier could disable 3 Italian battleships in a single night, with almost no casualties. The lesson was best learned by the Japanese to plan their attack on Pearl Harbor, which inflicted still more damages the next year.

At the start of the War in the Pacific, the Japanese had the most efficient force of carriers (the "Kido Butai"). Its destruction at Midway 6 months later marked the end of the Japanese expansion. One month before, the first battle beyond the horizon had taken place in the Coral Sea. At no time during the fight, any ship had seen an enemy ship. That form of war was to become the norm for all major naval confrontations of the war.

Outside the fleet carrier (20 000 to 30 000 tons, 50 to 100 planes on board), light carriers appeared during the war. They are smaller (often built on the hull of a cruiser and weighting around 12 000 tons). They can sail as fast as fleet carriers but they carry less planes (rarely more than 25). The US Navy built a dozen of them in 1942-43 to fill the gap before the arrival of the new generation of fleet carriers.

The escort carrier is a merchant ship with a landing deck above. She can not follow a fleet task group. She is too slow (less than 20 knots) and devoid of armor. Her main advantage is its low cost and short building time. The Americans will build more than 100 of them during World War 2, versus less than 50 carriers of all other kind put together.

They will play a major role in the victory against the U Boats in the Atlantic and will prove highly valuable to give air support during landing operations. Furthermore, they performed logistic tasks (such as plane ferrying), freeing the fleet carriers from that burden.

After their victory in the Pacific, the carriers seemed doomed to disappear after the war ! Nuclear tests at Bikini had shown their vulnerability to the new weapons. The war in Korea saved them, by showing how useful they were in the day-to-day confrontations of the Cold War. With the growing weight of the planes (emergence of the jets), only the biggest carriers of World War 2 could be still be used. The new ones became bigger and bigger, until reaching nowadays' mark of 90 000 tons for the giant American aircraft carriers. Some World War 2 veterans are still in service in the year 2000, but mostly as helicopter carriers.

The largest aircraft carrier of the war was the Japanese Shinano with no less than 70 000 tons. Her active career was very short: 9 days ! She was then sunk by an American submarine.

A cruiser is a multipurpose ship. She can play second fiddle to battleships during major gun battles or be the leader of an independent squadron in area where no battleship can be detached, by lack of resources or excessive risks. The cruiser has a large range, allowing her to "cruise" for long period in remote waters.

During World War 2, there are three kind of cruisers: the heavy, the light and the antiaircraft ones.

The heavy cruiser (10 000 to 12 000 tons, with 10 or so 8 inches guns) is a small battleship. A little quicker (she was able to follow the carriers, which was not the case of most battleships) and with a handsome armor.

The light cruiser (6 000 to 8 000 tons, with 10 or so 6 inches guns) is less protected (the French and Italian light cruisers were especially badly protected). Her role is more akin to that of destroyer, as flotilla leader. She can operate at the same speed, with guns and torpedoes and can provide a solid complement of firepower.

The anti-aircraft cruiser is as big as a light cruiser (sometimes as a heavy cruiser), she has more but smaller guns (5 inches or less) and are able to lay a deadly fire on incoming enemy planes. They rarely operate independently or against surface ships, by lack of heavier guns.

Cruisers were present in almost all battles, major or minor, of World War 2. The tendency was to decrease the main armament to reinforce the anti-aircraft protection. After the war, the heavy cruiser followed the example of her elder brother the battleship and disappeared. The light cruiser still exist but has lost most of her guns. They have specialized roles (anti submarines, anti aircraft, ...) and operate as part of a task force.

We must here mention the battlecruiser. She is not really a cruiser but rather a battleship (as to the weight and the weaponry), in which protection is sacrificed for the need of speed. That kind of ship proved a failure during the battle of Jutland, during World War 1. Almost only remnants of that period appeared in the order of battle during World War 2. The newly built battlecruisers were in a fact either full blown battleships (such as the Scharnhorsts) or very heavy cruisers (such as the American Alaska). Both had an adequate protection.

A last word to mention the auxiliary cruisers (Armed Merchant Cruisers) which were merchant ships with a couple of guns. They were used either to attack isolated merchant ships (the German used a dozen of them), or to defend them (the British had much more of them).

They owe their name to their first role, at the end of the 19^th century. With the discovery of the torpedo (at the time of the American civil war), came up quick small boats armed with the new weapon, the torpedo boats. Their mission was to weaken the enemy fleet with their "fishes" while avoiding the hits of the big guns thanks to their speed. The first counter measure was to equip the battleship with quick firing and smaller secondary guns. Afterwards came the idea of building specialized ships, aimed at "destroying" the torpedo boats with their guns. The destroyer was born.

With time, the destroyers received the very weapon they were committed to destroy: the torpedo. Little by little, their role expanded until it encompass all secondary tasks in a fleet: fight against submarines, attack of the enemy fleet with torpedoes, .... During World War 2 they also became anti-aircraft platforms.

If the aircraft carrier made the most of the second world war, the destroyer is following close. It was unthinkable during the war to let a major unit go out without her screen of destroyers. The destroyers veteran of the war were used by every navy on earth until they became too old or to worn down.

A destroyer weight from 1000 to 3000 tons. She sails fast, up to 40 knots. She is the fastest ship in the fleet. Her weak point is the range. Whereas a battleship or a cruiser can sail 10 000 miles upward, the destroyer can hardly put more than 1000 or 2000 miles, a couple of days of sailing. That forced the task forces during the war to perform lengthy and dangerous fueling operations, where either fleet tankers or bigger ships (carriers, battleships) gave away part of their fuel to the guzzling destroyers.

The armament of a destroyer is about 6 guns, around 5 inches (The Germans built bigger destroyers with 6 inches guns, but they were not successful). Some World War 1 leftovers had guns of less than 4 inches. The most deadly weapon of the destroyer was the torpedo. The Japanese developed the Long Lance before the war, an oxygen driven torpedo which was much more powerful than anything the Allies could fire at them. It made lots of damages to the allied squadrons, especially in the battles in the South Pacific.

Torpedo boats did not disappear with the emergence of destroyers. They remained in their shadow and evolved into smaller scale destroyer. Their weight did not top 1000 tons (against more the 2000 tons for destroyers). Their speed was comparable and they carried both guns and torpedoes. They can not be confused with the Motor Torpedo Boats, which were much smaller (100 tons, more or less) and operated near the coasts.

In 1942, a new category of destroyer emerged. They were the escort destroyers. Their main mission was to escort merchant ships and convoys. They look like destroyer but all their characteristics is a level below: their weight did not reach 1500 tons, their guns were less numerous and smaller (usually under 4 inches). They are slower (25 knots at most) and are usually devoid of torpedoes. Their enemy is the submarine, not a surface ship. The sailors in the escort destroyers at Samar had the emotion of their life when they caught sight of the Japanese big gun ships on the horizon !

Those are vessels specialized in the fight against submarines and convoy escort. Their characteristics and armament are very diverse. They can weight up to 2000 tons, they are rather slow (25 knots at their quickest), no protection, lightly armed against surface ships (no more than one or two guns, 4 inches or less). On the other hand, they are well equipped with depth charges and detection gears against submarines.

Those ships were produced in great quantities, especially by the British at the onset of the war, when they had to face alone the threat of the U boats in the Atlantic. Their role is less glamorous than their elder brother's, but it was essential. Several British sloop can boast more than 5 enemy submarines destroyed during the war, a record that only escort carrier can approach.

Modern fleet use such ships in great quantities, usually in a specialized role, anti submarines or anti aircraft.