Warship Nomenclature (Work in progress)

Discussion of naval matters is often clouded by the many and various names by which types of warships are known and by the varying definitions of those names.

Each nation has it's own traditions of naming warship types and these change over time.

In the British Royal Navy a "frigate" was originally a "cruising ship" which patrolled independently when not operating in support of the ships of the battle line.

This term was also colloquially applied to "post ships" which were not technically frigates.

When Her Majesty's Ship Warrior joined the fleet in 1861 she was rated as an "armoured frigate" despite being more powerful than any ship of the battle line.

By the end of the nineteenth century,"cruising ships" had become known as "cruisers" and the term "frigate" fell out of use.

During the Second World War a new type of dedicated anti-submarine escort was given the title "frigate".

It is from these escort vessels which the modern British anti-submarine frigate is desceded,even though today it performs roles similar to those of it's eighteenth century ancestors.

In the days of sail,the United States Navy also used the term "frigate" to describe a cruising ship,though these American ships were much larger than British frigates.

After World War Two,American frigates were large fleet escorts confusingly also known as destroyers and destroyer leaders (after 1975,many of these were redesignated as cruisers!).

The current Oliver Hazard Perry class frigates are simple,low cost escorts intended for non fleet work.

These are descendents of the Second World War "destroyer escort",the American equivalent of the British wartime "frigate".

American "DD" destroyers are more comparable to modern european "frigates".

The French navy seems to be confused,giving the destroyer's "D" flag superior to ships which it calls frigates.

The Japanese Maritime Self Defense Force has no "frigates" at all,it does however use the term "destroyer escort" to describe warships which would be frigates in most other navies.

While the latest Japanese "destroyers" are what most would refer to as "helicopter carriers".



The naming of different types of warships is a matter which has troubled seafighting men since the dawn of time.

Over two thousand years ago navies employed a rating system every bit as confusing as those in use today.

In ancient times rowed galleys  were rated by the number of files of oarsmen they carried on each side of the vessel.

The ram was the primary weapon of the warship and more oarsmen made a warship a faster more effective ram ship.

The ancient penteconters were uniremes with a single file of oarsmen to port and starboard.

Biremes had two rows of oars and oarsmen on each side.

Triremes had three rows of oars on each side.

However,quadquiremes instead had four oarsmen on each side,two per oar.

Just to add to the confusion there were also quinqueremes,hexaremes,septiremes,octeres,enneres and deceres.

Polyremes went all the way up to a "forty".

All of these ships had various combinations of more oars or more men per oar.

The distinction between ship types must have been every bit as unclear as the distinction between modern warship types.

Over the following centuries,sails became the primary means of propulsion at sea.

In the days of sail vessels were distinguished by the arrangement of their rigging.

Thus a sailor could distinguish between a brigantine,a snow,a brig,a ship or a schooner on the basis of her masts and sails.

However,vessels of many sizes often shared the same form of rigging.

For example,most large ships of the battle line were square rigged and three masted but so were frigates.

It was neccessary to differentiate between warships in other ways.

For five hundred years until the twentieth century the armament of warships was almost entirely made up of guns.

With all warships being similarly armed,warship types were differentiated by the number of guns they could carry.

This led to the development of the British Royal Navy's "rating system".

The most powerful warships were first rate "ships of the line" with 100 guns or more.

These were the vessels which were intended to do battle with enemy fleets.

Second rate ships were similar but carried fewer guns,though not less than 90.

Third rates were the mainstay of the battle fleet,carrying 60 to 90 guns.

Fourth rates were the smallest ships of the line which were also used as cruising ships.

Fifth rates were not ships of the battle line but "frigates",cruising ships with single gundecks and 30 to 44 guns.

Sixth rates were smaller "frigates" of 26 to 28 guns and "post ships" of 20 to 24 guns.

Below sixth rate were unrated minor warships such as snows,brigs,sloops,cutters and schooners which were usually defined by their rigging rather than their guns.

By the mid nineteenth century steam power was supplementing sail power on warships. 

By the end of the nineteenth century steam had replaced sails on most warships.

As warships no longer had rigging,terms such as brig,schooner and snow fell out of use for describing warship types.

With the advent of the Whitehead torpedo in the late nineteenth century naval warfare began a dramatic change.

Even the largest warships could be sunk by a weapon carried by the very smallest naval craft.

The threat posed by these "torpedo boats" was countered by a new type of warship,the "torpedo boat destroyer".

At the start of the twentieth century the torpedo armed "submarine" added to the range of threats at sea.

During the First World War the aircraft came of age as a weapon of war,attacking ships with torpedoes,bombs,guns and later rockets and guided missiles.

These developments rendered obsolete the historic order of precedence of warships as even the most powerful battleship could be sunk by both aircraft and submarines.

The number and size of guns a warship could carry became less important than it's ability to engage the whole range of threats.

As a ships rigging and number of guns was becoming irrelevant,warship types began to be named after the role they performed.

Ships of the line of battle became "battleships".

Frigates and other "cruising ships" became "cruisers".

The new torpedo carrying vesels were known as "torpedo boats".

Vessels designed to destroy torpedo boats were called "torpedo boat destroyers",later shortened to just "destroyer".

Submersible vessels were named "submarines".

While boats designed to hunt submarines were named "sub chasers".

The new aircraft carrying ships were simply named "aircraft carriers".

During the second world war there was an explosion of new types of warship.

The submarine threat to convoys led to the development of anti-submarine escorts which the British named "corvettes" and "frigates" despite them not being "cruising ships" like the corvettes and frigates of old.

Frequent amphibious operations led to a wide range of new amphibious warfare vessels.

Most new types of vessels were given descriptions rather than names.

The Landing Ship Dock.

The Landing Ship Infantry.

The Landing Craft Assault.

The Landing Ship tank.

The increased air threat led to the need for increased air defences on ships.

In addition,some vessels became specialised anti-aircraft ships.

Ships generally retained their earlier names when they took on new roles.

Cruisers in the anti-aircraft role were still cruisers.

Destroyers with added  anti-submarine capabilities were still destroyers.

Though the British reused the old terms "corvette" and "frigate" for new anti-submarine ships.

These descriptions were commonly abbreviated.

This led to a confusing array of acronymmery which continues to this day.

If an L.C.M. is a Landing Craft Mechanised,why is an L.C.S. a Littoral Combat Ship?

If an L.P.D is a Landing Personnel Dock,why is an A.P.D. an Attack Personnel Destroyer?

While there was a brief period of clarity at the turn of the twentieth century,today warship naming conventions are a mass of confusion.

There is now no clear definition of what constitutes a cruiser,destroyer,frigate,corvette,aircraft carrier or the recently fashionable "mothership".