WWII Warships:

WWII warships included Aircraft Carriers, Battleships, Battle Cruisers, Pocket Battleships, Cruisers, Destroyers, Torpedo Boats, Escort Carriers, Monitors, Frigates, Destroyer Escorts, Sloops and Corvettes; there were also other specific and smaller vessels such as Minelayers, Minesweepers, Motor Torpedo Boats, Motor Gun Boats, which I have not described due to their obvious nature and use.

Aircraft Carriers:

An Aircraft Carrier was defined as any surface vessel of war, whatever its displacement, designed for the specific and exclusive purpose of carrying Aircraft and so constructed that Aircraft could be launched therefrom and landed thereon; the Aircraft Carriers had sufficient speeds to operate with battlefleets, usually at around 30 knots; they carried Aircraft below deck in hangars, as well as on deck; a typical Aircraft Carrier could carry between 70 and 90 Aircraft, although some had fewer than this at the start of WWII.

Aircraft Carrier Development and History:

The development of naval air power began shortly after the invention of the Aircraft, with attention focussed on developing seaplanes for use in reconnaissance; most navies built seaplane Carriers, generally equipped with Torpedo carrying Aircraft; at the end of WWI several cargo ships had been sunk by Aircraft, but no warships had suffered more than slight damage.

At the start of WWII the ability of Aircraft to sink warships was still unknown and the initial performance of Aircraft Carriers was poor, with the Carrier HMS Courageous sunk by a Submarine and HMS Glorious sunk by the surface ships Scharnhorst and Gneissenau; however, once their true role was identified and their Escorts needs addressed the Aircraft Carrier soon became the offensive weapon of choice.

The Königsberg was the first major warship to be sunk by an Aircraft, on the 10th April 1940, signalling the shape of things to come; the Aircraft Carrier first showed its potential during the raid on Taranto in 1940, where 20 Carrier based Aircraft from HMS Illustrious left two Battleships with their keels resting on the bottom and damaged one other; however, it was in the Pacific theatre where the Aircraft Carrier revolutionised naval warfare.

From the first day of the Pacific war, when the Japanese attacked Pearl Harbour and sunk, or beached, five Battleships and damaged another three, with 360 of their Carrier based Aircraft, the Aircraft Carrier became the decisive factor of sea wafare.

The most striking example of the change in tactics brought about by the Aircraft Carrier was at the battle of Midway; the American and Japanese Aircraft Carriers duelled over a period of five days, hunting for each other, launching strikes and recovering Aircraft; at the end, four Japanese Aircraft Carriers had been sunk for the loss of one American Aircraft Carrier and the Japanese fleet was forced to retire; throughout the battle the fleets were more than 100 miles apart and the large, expensive Battleships were reduced to spectators.

If any doubt remained about the ascendancy of the Aircraft Carrier they were firmly dispelled by the sortie of the Japanese Battleship Yamato; the Yamato was the largest Battleship ever built, displacing 64,000 tons and armed with nine 18.1 inch (460 mm) guns; it was intended that she attack the US ships at Okinawa in a suicide attack, but whilst she was still only about 100 miles from the Japanese coast and over 200 miles from her target area, she was found by reconnaissance Aircraft and subsequently attacked and sunk with the loss of only 10 US Aircraft.

Aircraft Carriers became the most important ship in a fleet, due to their large radius of attack and the heavy punch associated with their Aircraft; conversely, they then became the main vessel of attack by opposing Aircraft, Submarines and surface vessels, who wanted to sink them; at first, this vulnerability was enhanced by the need for Carriers to steam in to the wind when launching or recovering Aircraft; this manoeuvre sometimes resulted in the Carrier moving away from the bulk of protective ships, although as the war progress tactics changed so that the protection followed the Carrier.

Carriers were also very vulnerable when preparing to fly off a strike force; with a mass of fully fuelled and fully armed Aircraft on and below deck, any successful attack could spark off a chain of destruction and result in the loss of a ship.


A Battleship was any surface vessel of war, the standard displacement of which exceeded 10,000 tons (10,160 metric tons), or with a gun above 8 inches (203 mm) in calibre; in the 1922 Washington Treaty it was agreed that no ships with a standard displacement of over 35,000 tons would be built, no ships fitted with guns in excess of 14 inches and no secondary guns fitted in excess of 6 inches, however this treaty lapsed shortly before the start of WWII; in addition, some existing ships that displaced more than 35,000 tons were permitted to be retained.

Battleship Development and History:

The Battleship is a direct descendant of the old ‘ships of the line’,alternatively known as ‘line of battle ships’; in the 19th century, fuelled by the industrial revolution, nations began to make widespread use of iron plating to give added protection to their large warship, and steam power began to replace sails for propulsion.

For a while it was possible to give ships so much armour that the latest guns could not penetrate it and ships had to be armed with rams as they were the only means of sinking another heavily armoured enemy; this sped up the efforts made to improve the power of guns, which resulted in the reduction, then total elimination, of the old broadside in favour of a smaller number of huge guns that could be traversed through a wide arc.

In the latter half of the 19th century a farcical situation had developed; the modern warships, known as Ironclads, were slow moving, unmanoeuvrable vessels armed with the most powerful guns in the world which nevertheless could not penetrate the armour of the enemy and due to the pitching and rolling of the ship at sea rarely hit the enemy anyway; battles resembled cumbersome dances, with ships manoeuvring to try to ram each other but rarely succeeding.

Eventually the power of the gun maker overcame the ability of the armourer to provide protection, but it took the development of effective range finding and fire control to give ships a realistic chance of hitting the enemy at anything beyond point blank range and not until oil power and steam turbines were developed could sufficient propulsion be provided.

The first vessel to take advantage of all these developments was the famous HMS Dreadnought, laid down in 1905; when she was commissioned she immediately made all previous ships obsolete due to her speed, numerous large guns, well located range finding, good fire control and well thought out arrangement of armour.

All subsequent Battleships ever made followed HMS Dreadnought’s fundamental design; the ultimate extension of the concept was the Japanese Battleship Yamato; this massive ship displaced 64,000 tons and was the largest Battleship ever built.

WWII Aircraft Carriers marked the end of an era for Battleships, with the Japanese attack on Pearl Harbour, where 360 Carrier based Aircraft sank or beached five Battleships and damaged another three; and with the British attack on Taranto, where 20 Carrier based Aircraft left two Battleships with their keels resting on the bottom and another one damaged; the Battleship became of secondary importance in sea warfare; their major contribution was in providing immense fire support to troops ashore.

Battleships are large, expensive ships and because of this they rarely operate alone; in the absence of a threat from the air, or in the days before the air threat was recognised, a typical arrangement would be for the Battleships to be protected from enemy ships by a screen of Cruisers and for Destroyers to screen the Cruisers from enemy ships.

More Destroyers would be used to screen the whole fleet from Submarine attack, or to sweep for mines ahead of the fleet; if opposing fleets met, the Battleships would form a line of battle and attempt to manoeuvre so that they maximised the number of guns that could fire on the enemy whilst minimising the number of enemy guns that could be brought to bear on them.

Cruisers or Destroyers would be sent to make Torpedo attacks on the enemy battlefleet, or were used to protect the friendly battlefleet from similar attacks by the enemy.

Battle Cruisers:

A Battle Cruiser is sub type of Battleship, the displacement of which exceeds 10,000 tons (10,160 metric tons), or with a gun above 8 inches (203 mm) in calibre, which is able to match speed with Cruisers in calm weather.

Battle Cruiser Development and History:

The battle Cruiser concept was a product of discussions relating to the most appropriate design for capital ships following the commissioning of the Dreadnought in 1909; lacking war experience with the new type of Battleship and being aware of the difficulty of hitting fast moving targets at sea, one school of thought proposed that a fast moving, heavily armed and lightly armoured ship would be superior to a slow moving, heavily armed and heavily armoured ship; this was based on the assumptions that the battle Cruiser would be unlikely to be hit, whereas the slower moving Battleship would be hit much more often and that gun power would overcome armour protection.

The most famous battle Cruiser of WWII was HMS Hood, which was hit and exploded during an engagement with the German Battleship Bismarck, leaving only three survivors; even today, the argument as to the exact series of events, the tactics employed and the final cause of loss rage undiminished.

No true role was found for battle Cruisers; their weaker armour made them vulnerable to Battleships, although their speed advantage were sometimes used to decisive effect; as with Battleships, they need to be screened from attack by Cruisers and Destroyers; they are best employed in fleets of similar fast vessels, as the presence of Battleships would slow them down and negate their speed advantage.

Pocket Battleships:

The term ‘pocket Battleship’ refers more to a class of very heavy Cruiser rather than to a specific type of ship; only three ships have ever been referred to as pocket Battleships and so a precise definition is difficult to give; however, they can be defined as Surface vessels of war, the standard displacement of which is around 10,000 tons and with a gun above 8 inches (203 mm) in calibre; they can be considered as large Cruisers with big guns; they have a typical Battleship type armament, with several large main guns mounted in turrets fore and aft, with Cruiser style guns mounted port and starboard adjacent to the superstructure; they have a moderate speed of (25 to 30) knots.

Pocket Battleship Development and History:

After the end of WWI, the Treaty of Versailles restricted Germany to a collection of vessels that were barely adequate for a coastal defence, consisting of 6 obsolete Battleships, 6 light Cruisers, 12 Destroyers and 12 Torpedo boats; the treaty permitted the replacement of the Battleships and Cruisers 20 years after launch, although the replacement Battleships were limited to a maximum of 10,000 tons displacement, which matched the tonnage of Cruisers.

Germany had great difficulty deciding on an appropriate design of ship to replace the very old pre Dreadnought era Battleships; the tonnage limitation was severe, making it impossible to build a ship that was heavily armed and heavily armoured; faced with treaty limitations on the number of ships and with potential threats from Russia, Poland and France, the choice of design was not easy.

It was eventually decided to build a ship, the Deutschland, that was well armed, with six 11.1 inch guns and eight 5.9 inch guns, but with only a moderate speed of 26 knots and a long endurance, over 18,000 miles at 15 knots; she was also provided with eight Torpedo tubes, a multitude of smaller guns and two Aircraft for scouting purposes; due to weight restrictions, however, little armour could be provided.

Such an arrangement made the vessel ideal for commerce raiding, with the ability to stay at sea for a long time, sufficient speed to catch any Merchant cargo vessel and escape from any superior vessel, sufficient armour to be protected against the guns from any Merchant vessel and finally with sufficient guns to overcome any Merchant vessel and most warships; but by the time WWII began the speed of modern Battleships was comparable with that of the pocket Battleship.

The vessel actually displaced over 11,500 tons standard, over 15,000 tons fully loaded; however, the ship was a creditable effort to keep within the Versailles treaty limits whilst still providing a useful warship; due to the Battleship type gun arrangement being combined with a relatively tiny hull, she was referred to as a ‘pocket’ Battleship by the rest of the world; two other warships followed; the Admiral Scheer and the Admiral Graf Spee; these ships differed in detail to the original and to each other; however none of the fundamental design elements was altered.

The Admiral Graf Spee is probably the most famous pocket Battleship; she made an extended raid in the South Atlantic, staying at large for many months and causing considerable disruption to shipping before being scuttled in Monte Video harbour after being convinced that a superior force was awaiting her at sea.

Pocket Battleships were mainly used as Merchant raiders; although heavily armed, the light armour made the ships extremely vulnerable and thus all ocean going warships posed a potential threat; victory could be assured against Cruisers or smaller vessels if encountered singly, as the long range and heavy hitting ability of the Pocket Battleship's main guns would discourage attempts of the enemy to bring her to within range of the smaller guns mounted by their vessels.

And if the range closed, the secondary armament of the Pocket Battleship added to the weight of shot, making it difficult for even a group of Cruisers to defeat her; nevertheless, disengagement was a priority, as the Pocket Battleship's armour could not be relied upon to ensure hull integrity or to protect vital areas in a prolonged engagement.


A Cruiser can be defined as a surface vessels of war, the standard displacement of which is less than 10,000 tons (10,160 metric tons) and which exceeds 1,850 tons (1,880 metric tons), or with a gun above 5.1 inch (130 mm) calibre; Cruisers are divided into two sub-categories, Heavy Cruisers, carrying a gun above 6.1 inch (155 mm) calibre and Light Cruisers, carrying a gun not above 6.1 inch (155 mm) calibre.

Cruisers were usually armed with Torpedo tubes and often fitted with facilities for carrying one to three floatplanes; they usually had a top speed of around 30 knots, were designed to mix speed with range, endurance and firepower and were expected to be able to out run any ship they could not out fight.

Cruiser Development and History:

Cruisers developed out of a multitude of needs, related to the move from wind power to steam power and the advent of wireless communications; in the days of sail, the ability of a ship to stay at sea was limited by how much food and water could be carried, with re-supply being easy and quick at sea; long journeys away from port were possible for all vessels, with nothing except journey time preventing even far flung seaways being patrolled.

However, with the advent of steam power, ships could no longer stay at sea for extended periods; the supply of coal and then oil, was limited to established facilities and replenishment could not easily be carried out at sea; this had the effect of making close blockade of ports impossible and of protecting trade routes difficult.

There was a clear need for a vessel which had good endurance, in order to make extended patrols, had significant size, to prevent the enemy from easily driving the vessel off its patrol area, and had enough speed to be able to shadow and report enemy warships once discovered, to enable them to be brought to battle by the main fleet; the Cruiser filled this need.

Over time, the role of the Cruiser developed in to several main functions; protecting, or attacking, remote trade routes; patrolling off enemy shores, blockading; reconnaissance; shadowing a larger enemy vessel and the protection of other ships; during WWII, Cruisers undertook all of these tasks and proved their value repeatedly.

Cruisers were used extensively during WWII; their air defence capability was particularly vital in the Pacific and Mediterranean; their endurance was valuable in hunting commercial raiders worldwide and their ability to shadow larger ships was demonstrated in the Bismark chase; smaller and cheaper than a Battleship, yet larger and more powerful than a Destroyer, the Cruiser could be used whenever significant firepower was needed but when a Battleship could not be risked; when with the fleet they were expected to screen the main ships, protecting them against Aircraft and enemy Cruisers; during a fleet action they were expected to counter any attack by enemy Cruisers and could use their own Torpedoes to attack enemy capital ships if needed.


A Destroyer can be defined as a surface vessel of war, the standard displacement of which is greater than 600 toms (610 metric tons) and does not exceed 1,850 tons (1,880 metric tons) and with a gun not above 5.1 inch (130 mm) calibre; most Destroyers were fitted with four or six main guns, smaller calibre canon or machineguns, Torpedoes, mine sweeping equipment, depth charges and asdic, sonar; some Destroyers were fitted for mine laying, although this was unusual; they usually had a top speed of over 35 knots.

Destroyer Development and History:

With the advent of self propelled Torpedoes, thoughts in many nations turned to the possibilities of being able to defeat any fleet blockading a port with a multitude of cheap coastal Torpedo boats, or to defeat larger enemy ships at sea with cheap ocean going Torpedo boats; in order to provide a defence against this potential threat, there was seen to be the need for a small, fast, ocean going boat that could travel with the fleet at sea to their destination and then protect the fleet from Torpedo boat attacks on arrival; thus the Torpedo boat Destroyer, soon known simply as the Destroyer, was born.

A dual role for Destroyers was very quickly seen; being large enough to travel with a fleet at sea and fast enough to fight Torpedo boats, Destroyers could be used as ocean going Torpedo boats, posing a threat to even the largest ship in a fleet action; they became essential to the fleet, providing a screen for larger ships from potential attacks from similar vessels and being seen to be useful for most of the multitude of small tasks that are required in any navy.

When ocean going Submarines became widespread, the protective role for the fleet from Submarines naturally fell onto the Destroyer as an extension of their normal screening operations and a minesweeping role was also added; due primarily to their anti Submarine capability, Destroyers were used to Escort Merchant ships in both WWI and WWII.

Whilst the fleet was at sea Destroyers were expected to prevent Submarines from getting in range to attack Cruisers, Battleships or Aircraft Carriers; once battle was joined they were expected to prevent enemy Destroyers closing in to engage the larger ships with Torpedoes and if ordered to close with larger enemy ships and attack them with their Torpedoes; they were also used when larger ships could not be risked and were described by one British Admiral as being 'expendable'.

They were often used for scouting waters that were feared to contain mines, Submarines or other hazards, or for work very close to shore, which might expose the ships to increased chance of bombardment or air attack.

Torpedo Boats:

A Torpedoboat can be defined as a surface vessel of war whose main armament is Torpedoes; a Torpedo boats was generally under 1000 tons and was intended to travel at sea with the battlefleet to attack major enemy warships.

Torpedo Boat Development and History:

When the self propelled Torpedo was invented, countries with small navies saw this as a way of beating big navies cheaply; they developed small boats that could sail out from harbour to attack an enemy fleet with Torpedoes; this concept then grew into the idea of taking small, fast Torpedo boats along with the fleet to attack enemy fleets when they met at sea.

These small, fast Torpedo boats had to be big enough to keep up with the fleet during heavy weather and carry enough fuel to stay with the fleet for a while; they did not have a big impact in WWII as the Torpedo carrying Aircraft became the principal threat to major surface warships; the task of the Torpedoboat was to manoeuvre to avoid enemy Destroyers and sink the enemy warships with Torpedoes.

Escort Carriers:

Escort Carriers were smaller, less well armed and slower than the Aircraft Carriers; they can be defined as any surface vessel of war, whatever its displacement, designed for the specific and exclusive purpose of carrying Aircraft and so constructed that Aircraft can be launched therefrom and landed thereon and with a maximum speed of less than 20 knots.

Escort Carrier Development and History:

During WWII the threat from Aircraft was seen to be very high; the presence of friendly Aircraft brought with it a large degree of security, whilst enemy Aircraft brought with them fear and death; this applied equally to land as well as the sea; Aircraft Carriers were available, but they were small in number and expensive to produce due to their size and speed.

The Escort Carrier was conceived as a small, slow Carrier to keep pace with Merchant ships; the initial Escort Carriers were basically converted Merchant ships; however, specific designs soon appeared; in the Atlantic, Escort Carriers sailed with convoys to protect them from Submarine attack; the mere presence of an Aircraft with a convoy made a huge difference, forcing Submarines to dive and loose contact.

In the Pacific, Escort Carriers not only provided air cover for large masses of shipping against air attack, they also provided Aircraft in a ground attack role.


A monitor may be defined as a surface vessel of war fitted with a gun above 8 inches (203 mm) in calibre and intended for use in a shore bombardment role.

Monitor Development and History:

Monitors were developed from a need to provide cheap big gun fire support to forces ashore and out of a desire to use ‘spare’ Battleship turrets; whilst the Battleship could, and did, fulfil the shore bombardment role, they were designed to fight opposing Battleships at sea; this made them very expensive, due to their need for high speed, significant armour protection and good sea keeping qualities; a monitor provided all the benefits of a Battleship for shore bombardment, big guns, without the expensive and unnecessary features of a Battleship.

Frigates, Destroyer Escorts & Sloops:

Frigates, Destroyer Escorts and Sloops are very similar vessels; they generally have anti Submarine capabilities similar to, or superior to, a Destroyer, but lack a Destroyer’s speed and armament and were considered to be Destroyers that were specially adapted for anti Submarine operations; they could be defined as surface vessels of war, the standard displacement of which is greater than 600 toms (610 metric tons) and does not exceed 1,850 tons (1,880 metric tons), with a gun not above 5.1 inch (130 mm) calibre and no more than four guns above 3 inch (76 mm) calibre, do not carry Torpedoes and are equipped for an anti-Submarine role.

They carried modern anti Submarine equipment; sonar and depth charges were standard, whilst ahead firing weapons and radar were common and were capable of moderate or significant sustained speed.

Frigates, Destroyer Escorts & Sloop Development and History:

Although Frigates have been in service since the days of sail, the modern Frigate was developed to fulfil a specific role; that role was in providing a fast Escort vessel, primarily for hunting Submarines; it was found during WWII that existing Destroyers were too expensive and in too short a supply to be used as Escort vessels.

Destroyers were designed to operate with a battlefleet, with significant firepower, guns and Torpedoes, that were for the sole purpose of defeating enemy Destroyers and sinking larger ships, such as Cruisers and Battleships; this equipment was redundant in convoy Escorts, where the main threat came from Submarines or Aircraft; in addition, Destroyers were capable of very fast speeds for short periods of time and had a short endurance; great bursts of speed were not needed for hunting Submarines, although there was a need to be able to move quickly to react to a threat, or catch up with a convoy after a prolonged hunt.

Thus the Frigate, Destroyer Escort, was conceived as a small ship that did not carry this redundant equipment, but was capable of reasonable sustained speed and with a good endurance; the main guns were reduced in number and size and the Torpedo tubes were removed; thus the Frigate retained only the equipment necessary for its role as an Escort and lost any offensive capability against warships; the maximum speed could be up to 25 knots, which was comparable to a Destroyer’s cruising speed and they had much increased fuel capacity.

Frigates made ideal anti-Submarine vessels and they usually formed the bulk of the Atlantic support groups, hunter-killer groups, and due to their speed were able to react quickly to threats; when forming part of a convoy Escort their speed enabled them to catch any surfaced Submarine.


A Corvette may be defined as a small, cheap vessel that can be produced quickly and is equipped for anti Submarine operations; they were used by the British as small, cheap ships that could provide anti-Submarine Escort for convoys; two main types of Corvette were produced, the Castle class and the Flower class; they were based on the design of a commercial whale catcher and were fitted with asdic and depth charges; one small deck gun was fitted, for fighting a surfaced U-boat; later versions were also fitted with radar.

Corvette Development and History:

The Corvette was conceived in 1939 as a small anti Submarine vessel for use in coastal waters; the vessels had excellent sea keeping abilities and when faced with a shortage of seagoing Escorts they were also assigned to ocean convoy routes; they were weak against surfaced U-boats, as their maximum speed of only 16 knots was not sufficient to catch a U-boat on the surface and their small 4 inch deck gun was matched by a similar weapon on the U-boat; in addition, their slow speed meant that after any prolonged hunt the ship could not quickly rejoin the convoy.

Despite being uncomfortable vessels to sail in due to their severe roll motion, they were able to operate in conditions that would have damaged Destroyers; these ships will always be associated with the battle of the Atlantic and were operated by many Allied nations.

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