Definitions of Vessel Types
Aircraft Carriers
Aircraft carriers are medium to large sized ships that
exist to carry and operate combat aircraft, both fixed-wing and rotary. A
number of amphibious ships also carry and operate aircraft, but they do so
primarily to support amphibious operations. This category of vessel type will
include the following three types of aircraft carriers in operation with world
navies:
- Conventional Take Off and Landing (CTOL) aircraft
carriers (CV/CVN) - Currently, Brazil, France, and the United States are
the only nations that operate large-deck aircraft carriers that can accommodate
CTOL aircraft. A CTOL aircraft carrier requires steam catapults, an angled
recovery deck, and arresting gear; features that significantly increase cost
and ship size.
- Short Take Off and Vertical Landing (STOVL) aircraft
carriers (CVS) - A number of nations (India, Italy, Russia, Spain,
Thailand, and the United Kingdom) operate smaller aircraft carriers (generally,
11,000 to 21,000 tons, but Russia's Kiev class is considerably larger at 48,500
tons) that operate STOVL aircraft, primarily Harriers. A STOVL aircraft carrier
does not require catapults, an angled recovery deck, or arresting gear, but is
usually fitted with a ski jump forward to facilitate short take offs. Korea,
Turkey, and Japan have also expressed interest in acquiring aircraft carriers,
and may build smaller ships capable of operating STOVL aircraft. The United
Kingdom will return to big-deck carrier operations with its Future Aircraft
Carrier (CVF) Program, which will commission one ship in 2012, and a second in
2015. The United Kingdom is examining CTOL, STOVL, and STOBAR options for the
CVF, but is believed to favor the STOVL option. China is also reportedly is
developing a big-deck aircraft carrier that may enter service around 2010, but
no firm information is currently available as to the type of aircraft that will
operate from its deck.
- Short Take Off But Arrested Recovery (STOBAR)
aircraft carriers (CV) - Russia is the only nation in the world with an
aircraft carrier, Admiral Kuznetsov, that operates STOBAR aircraft. A STOBAR
aircraft carrier is a compromise option; like a CTOL aircraft carrier, it is
fitted with an angled recovery deck and arresting gear, but like a STOVL
aircraft carrier, it has a ski jump forward and no steam catapults.
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Submarines
Submarines are extremely popular with world navies and
this category of vessel type will include the following four general types:
- Ballistic Missile Nuclear-Powered Submarines (SSBNs)
- SSBNs, the most powerful warships afloat, are operated by only a few of
the world's nuclear powers: China, France, Russia, the United Kingdom, and the
United States.
- Nuclear-Powered Attack Submarines (SSNs) - SSNs
are the most capable general-purpose submarines, but only a few blue-water
nations (China, France, Russia, the United Kingdom, and the United States) can
currently afford to build and operate nuclear submarines. However, Brazil and
India have programs in place to develop an indigenous nuclear submarine
construction capability.
- General Purpose Diesel-Electric Submarine (SS) -
Diesel-electric submarines are the most common submarines and are operated by a
large number of the world's navies.
- Small Special Purpose Midget Submarines and Swimmer
Delivery Vehicles - This would include small midget submarines such as the
COSMOS type as well as dry and wet swimmer delivery vehicles.
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Cruisers (CG)
A cruiser is the largest type of surface combatant
currently in-service or planned for service in world navies.A cruiser generally
displaces over 10,000 tons, and is fully capable of a wide-range of independent
warfare operations in a multi-threat environment.
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Destroyers (DD or DDG)
A destroyer is smaller, and less capable than a cruiser,
but is also capable of operating independently in a high-threat environment.
Destroyers have steadily grown in size (now 5,000 to 10,000 tons), expense
(nearly US$700 million apiece) and capability. Generally, a destroyer is
considered to be a ship that has all of the sensors (including a sophisticated
phased-array radar), combat systems, and weapons needed to operate in a
high-threat environment. A number of world navies are currently building ships
that, while called frigates, more accurately represent destroyers in size and
capability. Examples include the Spanish F-100, the German F-124, and the Dutch
De Zeven Provincien classes (all are highly capable ships displacing over 5,000
tons and carrying phased-array radars).
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Frigates (FF or FFG)
A frigate is a medium-sized surface combatant (between
2,000 and 5,000 tons) that is either suited for one specific role
(anti-submarine warfare or anti-air warfare), or has lesser all-around
capabilities than a destroyer. A frigate may be less capable than a destroyer,
but is still a relatively sophisticated and expensive (averaging around US$325
million apiece) platform. A frigate is generally the smallest surface combatant
that can conduct extended blue-water missions in a high-threat
environment.
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Corvettes (FS)
Corvettes are fast (around 25 knots or better), well-armed
ships that displace between 700 and 2000 tons. A corvette is generally not
intended for extended ocean-going operations, and is best suited for regional
operations. Corvettes are generally the smallest platforms capable of
accommodating the sensors, weapons, and combat systems needed to operate in a
medium threat environment. Corvettes are sometimes referred to as light
frigates (FFLs). It can be assumed that the hull design for a corvette and that
of an offshore patrol vessel are very similar. The differences will be in
propulsion and outfitting. Corvettes will have higher speed and therefore less
endurance and range than OPV, much greater armament, and less space for
provisions and habitability.
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Fast Attack Craft (FAC, also
referred to as PTGs or PCGs)
FACs are small (under 700 tons), fast (over 25 knots)
vessels that are intended for quick, hit-and-run strike operations within 100
miles of the coast. FACs are primarily armed for a limited anti-surface warfare
(ASUW) mission. They may bristle with a number of guns, torpedoes, and
surface-to-surface missiles (SSMs) and thus present a credible threat to
surface ships. However, a FAC lacks the range, seakeeping qualities and
defensive systems needed to operate independently for any extended length of
time in a high or medium-threat environment. FACs are generally employed by
nations that plan to operate them close to shore, or in the shelter of
archipelagoes (e.g. the Aegean, Norwegian fjords, or the South China Sea).
Generally, FAC hulls are thin and made of aluminum or steel. Because of their
thin hulls, modifications are more difficult to make and life expectancy is
reduced.
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Offshore Patrol Vessels
(OPV)
In response to a number of environmental and economic
concerns, world navies and/or coast guards developed a type of patrol vessel,
the OPV, which is capable of patrolling the waters of an Exclusive Economic
Zone (EEZ) for extended lengths of time. By virtue of its mission, an OPV must
be relatively large (generally over 700 tons) to possess the necessary range
and seakeeping characteristics needed for extended offshore patrols. The higher
in latitude a Navy operates (North or South of the Equator), the larger the
wave heights and therefore the larger an OPV will be. For example India
operates in waters that are known for very rough conditions. Some Indian OPVs
are beyond 2,000 tons displacement. An OPV is often built to commercial
standards and is slower (generally around 20 knots) than its corvette and
frigate cousins. However, some nations will build OPVs with space and weight
margins for future weapons upgrades. These types of OPVs will generally be
built to naval standards including hull and equipment shock requirements. An
OPV is generally lightly armed (a medium-sized gun), but is sometimes fitted to
carry surface-to-surface missiles (SSMs) or ASW equipment in wartime. Most new
construction OPVs are also equipped with a helicopter deck and hangar to
enhance its patrol capabilities. It can be assumed that the hull design for a
corvette and that of an offshore patrol vessel are very similar. The
differences will be in propulsion and outfitting for each application. Offshore
patrol vessels will have slower speed, less armament, and greater space for
provisions and habitability thereby allowing for greater endurance and range.
:p>
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Patrol Vessels
This vessel type
category will include the following patrol vessel types:
- Patrol Boat (PBs) -
Patrol Boats are smaller than OPVs and larger than PCs, thus filling the range
between 100 and 700 tons. A PB is designed for multi-day patrol operations
(anti-smuggling, search and rescue, coastal security, etc.) in coastal waters.
A PB is often armed with a small to medium caliber gun (typically a 76mm and/or
40mm gun) and machine guns. It may also be fitted for, but not with,
surface-to-surface missiles (SSMs).
- Patrol Craft (PC) - Patrol craft are small
(under 100 tons) and are intended to conduct short patrols (anti-smuggling,
search and rescue, harbor security, etc.) in relatively sheltered coastal
waters, harbors, or rivers. Patrol craft are lightly armed (usually machine
guns) and have limited range.
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Mine Countermeasures Vessels
(MCMV)
An MCMV is any vessel designed to locate and neutralize
naval mines. A number of ship types fall within the MCMV category:
- Mine Countermeasures Support Ship (MCS) - An MCS
provides command, control, communications, and logistics support to mine
warfare operations. An MCS is frequently an auxiliary-type ship, but some are
also capable of operating MCM helicopters.
- Minehunting Ship (MHS) - A MHS is a ship,
generally over 500 tons, that is equipped with specialized sensors (usually
fitted in a remotely operated vehicle (ROV)) to locate and destroy mines. An
MHS may or may not also carry the traditional mine sweeping arrays that
characterize a minesweeper.
- Fleet Minesweeper (MSF) - A MSF is a ship,
generally over 500 tons, that is fitted to tow sweep arrays to locate and
neutralize moored and bottom mines.
- Coastal Minehunter (MHC) - A MHC is smaller than
an MHS, generally under 500 tons, and is intended for operations in coastal
waters.
- Coastal Minesweeper (MSC) - A MSC is smaller
than an MSF, generally under 500 tons, and conducts sweep operations in coastal
waters.
- Minelayer (ML) - A minelayer is designed to lay
naval mines; however, it often performs additional tasks such as serving as an
MCS, a training ship, or a patrol vessel.
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Amphibious Ships
Amphibious ships are ocean-going vessels that are capable
of conducting amphibious operations with either embarked aircraft or amphibious
landing craft. There are a number of ship types that fall within the larger
category of amphibious ships:
- Amphibious Assault Ship,
General Purpose (LHA) - A medium to large-sized ship (20,000 to 40,000
tons) that has a full flight deck and hangar for carrying and operating
helicopters and supporting VSTOL aircraft, and a well-deck for carrying and
operating embarked landing craft. The US Navy's Tarawa class is an
example of a LHA.
- Amphibious Assault Ship,
Multipurpose (LHD) - A medium to large-sized ship (20,000 to 40,000 tons)
that has a full flight deck and hangar for carrying and operating helicopters
and supporting VSTOL aircraft, and a well-deck for carrying and operating
embarked landing craft. The US Navy's Wasp class is an example of a
large LHD (displacing around 40,000 tons) and France’s new Mistral
class is an example of a medium-sized LHD (displacing around 21,000 tons).
- Amphibious Assault Ship,
Helicopter (LPH) - A medium-sized ship (approximately 20,000 tons) that has
a full flight deck for carrying and operating helicopters and supporting VSTOL
aircraft. The Royal Navy's Ocean class is an example of a LPH.
- Amphibious Transport, Dock
(LPD) - A medium-sized ship (10,000 to 25,000 tons) that has a well-deck
aft for carrying and operating embarked landing craft. An LPD also has a flight
deck, usually aft over the well-deck, for operating up to five helicopters. An
LPD differs from a Landing Ship, Dock (LSD) in that an LPD usually carries
large numbers of troops at the expense of vehicles and cargo.
- Landing Ship, Dock (LSD)
- A medium-sized ship (10,000 to 25,000 tons) that has a well-deck aft for
carrying and operating embarked landing craft. An LPD also has a flight deck,
usually aft over the well-deck, for operating up to five helicopters. An LSD
differs from an LPD in that an LSD usually carries vehicles and cargo, while an
LPD carries large numbers of troops.
- Landing Ship, Tank (LST)
- A ship designed to beach and discharge personnel, vehicles, and cargo via
a bow ramp system. Usually over 2,000 tons full load displacement and capable
of landing over 400 metric tons of cargo.
- Landing Ship, Logistic
(LSL) - Similar to an LST, but may not have a beaching capability.
- Landing Ship, Medium (LSM)
- A ship designed to beach and discharge personnel, vehicles, and cargo via
a bow ramp. Smaller than an LST, under 2,000 tons full load displacement and
capable of landing under 400 metric tons of cargo.
- Amphibious Transport (LPA)
- A ship designed to carry assault troops to the site of an amphibious
operation. Troops are delivered to the beach by embarked landing craft launched
via davits or cranes. An LPA is not equipped with a well-deck.
- Amphibious Cargo Ship
(LKA) - A ship designed to carry vehicles and cargo to the site of an
amphibious operation. The cargo is delivered to the beach by embarked landing
craft launched via davits or cranes. An LKA is not equipped with a
well-deck.
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Amphibious Craft
Amphibious craft are far smaller than amphibious ships,
usually under 1000 tons, and are designed to beach and discharge their cargo
via a bow ramp. An amphibious craft is not an ocean-going vessel, and is
frequently carried in a larger amphibious ship. These types of vessels are made
of steel and are easily repaired and maintained for years. Propulsion and
control systems are generally the only elements that need overhaul or upgrading
A wide variety of small amphibious vessels fall within the category of
amphibious craft:
- Landing Craft, Assault
(LCA) - An LCA is a small (under 20 tons), high-speed (up to 35 knots)
vessel intended to carry a small number of troops (under 20) for quick assaults
or commando-style operations. An LCA does not have a bow ramp, so troops
disembark over the side or via inflatable rafts. An LCA is not usually carried
by amphibious ships, but is used for short-range coastal operations.
- Landing Craft Air Cushion
(LCAC) - An LCAC is a high-speed (up to 40 knots) vessel able to carry
troops, vehicles, and cargo across the beach from over-the-horizon distances.
LCACs can usually be carried in the well-decks of LHAs, LHDs, LPDs, and LSDs.
An LCAC generally displaces around 180 tons.
- Landing Craft, Medium
(LCM) - A beachable vessel capable of transporting up to 100 tons of
vehicles, cargo, and personnel. An LCM can be carried by larger amphibious
ships in well-decks, or as deck cargo using davits for on/offload. An LCM
usually displaces around 125 tons.
- Landing Craft, Personnel
(LCP) - A small (10 tons) vessel used to transport personnel and limited
cargo to a beach. An LCP does not usually have a bow ramp, so troops disembark
over the side or via inflatable rafts.
- Landing Craft, Tank (LCT)
- A larger vessel (700 tons) that can carry heavy armored vehicles in an
open deck area forward. An LCT is designed to beach and discharge troops,
vehicles, and cargo onto the beach via a bow ramp. An LCT is usually too large
to be embarked in an amphibious ship.
- Landing Craft, Utility
(LCU) - An LCU is generally and open-topped vessel designed to beach and
discharge troops, vehicles, and cargo onto the beach via a bow ramp. An LCU is
not large enough to make extended ocean voyages, and can be carried in the
well-decks of LHAs, LHDs, LPDs, and LSDs. An LCU usually displaces between 100
and 450 tons.
- Landing Craft, Vehicle/Personnel (LCVP) - An
LCVP is a ship-transportable capable of carrying troops, cargo, and small
vehicles to the beach. An LCVP usually displaces less than 25 tons.
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Auxiliaries
The Auxiliary category covers a large number of ships and
small craft of various types that support naval operations. To limit the
problem to a manageable scope, AMI focuses on larger ships (over 1000 tons)
that are capable of ocean going operations. Some of the Auxiliary ship types
that AMI covers include:
- Intelligence Collection Ship (AGI) - A ship
designed to collect intelligence on foreign nations, mostly electronic
intelligence, but also acoustic and electro-optical intelligence.
- Missile Range Implementation Ship (AGM) - A ship
designed to collect data about domestic missile tests, and to support
missile-firing trials of the ship's navy.
- Oceanographic Research Ship (AGOR) - A ship
intended to gather information on the physical and biological properties of the
world's oceans.
- Hydrographic Survey Ship (AGS) - A ship designed
to perform bottom surveys and to process data for the creation of navigational
charts. An AGS also often has the capability to perform oceanographic research
functions as well.
- Cargo Ship (AK) - A cargo ship transports dry
cargo in support of naval forces or forward deployed ground forces. An AK
generally does not have the capability to perform underway replenishment
operations.
- Oiler (AO) - An AO carries fuels to naval ships
at sea and can transfer those fuels via underway replenishment operations. An
AO often can carry small quantities of ammunition, cargo, and provisions as
well.
- Replenishment Oiler (AOR) - An AOR, also
referred to as an AOE (Fast Combat Support Ship) in the US Navy, can carry a
full-range of fuels, ammunition, cargo, and provisions (dry and refrigerated)
for underway replenishment operations.
- Salvage and Rescue Ship (ARS) - An ARS supports
salvage, rescue, and firefighting operations.
- Submarine Rescue Ship (ASR) - An ASR is
primarily designed to rescue personnel from sunken submarines, but can also
perform general salvage and ocean towing functions. Most navies that operate
submarine forces maintain at least one ASR.
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