• Forum
• SITREP

• Military

• Introduction
• Systems
• Facilities
• Agencies
• Industry
• Operations
• Countries
• Hot Documents
• News
• Reports
• Policy
• Budget
• Congress
• Links

• WMD
• Intelligence
• Homeland Security
• Space
• Public Eye

Further Reading

Aviation Amphibious Assault Ship (LPH / LHA)

In 2011, an analysis published by the US Naval Institute noted that "local observers now expect China to build up to six Type 071s along with six flat-deck helicopter carriers." There is no evident discussion in the open literature about a Chinese amphbious aviation ship, but it is a logical companion to the Air Cushion Vehicle (ACV) capabilities of the Type 071 Yuzhao class. Future military forces require enhanced vertical lift capabilities in a compact package.

The overall design space is probably bounded by the American LPH and LHA designs, of 20,000 tons and 45,000 tons, respectively. The most straightforward design, with Chinese characteristics, of such a ship would be an adaptation of the Type 071 Yuzhao LPD, replacing the LCAC dock in the hull with a hangar deck, and extending the helicopter landing deck from two to four spots. The vessel has an overall length of 650 feet / 200 meters, overall beam of 100 feet / 30 meters, waterline length of 555 feet / 170 meters.

Such a veseel would have a hull and diesel propulsive system; a main deck divided into a short exposed forward section, an intermediate section comprising about a tenth the main deck, and an aft exposed section; an upper deck on which superstructure items are located; a flight deck extending along most of the aft main deck; a hangar below the aft deck section, this hangar's roof being the upper flight deck; pads located on the aft deck sections; and parking areas located on the aft deck section.

Adapting this vessel into an other-role ship is possible because such ships' main decks are half to three fourths exposed and have missile launchers, guns, cranes, gantries or the like and helicopter pads on the exposed sections, on this vessel those deck items are placed beside, abaft, above or straddling the flight deck, while the upper hangar and elevator to the lower hangar are incorporated in the forard superstructure, with funnel uptakes leading to it being located in the upper hangar walls. The deck of this vessel is roughly the size of such ships' present decks and its hangar and superstructure not top-heavy because they are of light construction and, because the air group is housed in the lower hangar. The all-weather capability, the high freeboard, broad deck and heavy equipment these require only being provided to an extent justified by the vessel's and air group's size, cost and role. The upper hangar and elevator to the lower hangar being provided with only minimal fittings, helicopters are are relocated to the lower parking area.

Helicopters are typically configured to perform specific roles such as troop transportation, cargo transportation, assault, medical evacuation, surveillance, AWAC, rescue, firefighting, construction, etc. Military helicopters are often designed with interior accessories to accommodate passengers and/or cargo. Various attachments are available to mount weapons, equipment, hoists, etc. There are a large number of classes of amphibious ships around the world with each having its basic specialized mission. For example, the U.S. Navy has (LCC) Amphibious Command Ship, (LHA) Amphibious Assault Ship (General Purpose), (LHD) Amphibious Assault Ship (Multi-Purpose), (LKA) Amphibious Cargo Ship, (LPA) Amphibious Transport, (LPD) Amphibious Transport Dock, (LPH) Amphibious Assault Ship (Helicopter), (LSD) Dock Landing Ship, and (LST) Tank Landing Ship. Other amphibious ships are used commercially in missions such as Roll On/Roll Off (RO/RO) vehicle carriers, container carriers, and break bulk in open top containers. The United States Navy and other navies around the world have deployed several primary classes of amphbious assault ships:

• 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.
• 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.
• 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 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).

The primary drawback of each of the above mentioned vessels is that each class of vessels is optimized for a single specific mission. Many classes of vessels would be required to fulfill all the possible specific needs. The purchase cost for each vessel can be prohibitive as well as the maintenance and ongoing costs associated with each vessel.

Typically before construction, each amphibious support vessel must be custom configured depending upon its chosen mission. A need exists for a standardized multi-purpose amphibious support vessel having a standardized hull capable of having a plurality of optional operational structures for carrying out a variety of missions, and capable of receiving a plurality of modular habitable containers for supporting troops and the like. Because of the standardized hull design the optional operational features advantageously can be readily integrated into the vessel so that the vessel will be capable of carrying out a wide variety of operational missions with the optional operational structures selected before the vessel is constructed.

CTOL and STOL carriers, including helicopter ships, share a common configuration: a hangar enclosed within a hull, a large flight deck on the hangar roof, take-off runway/s, landing runway/s and pad/s on that flight deck, lifts connecting the hangar and flight decks, and a superstructure off to one side of the flight deck. CTOL carriers such as the USS Nimitz have catapults, arresters and, usually, several runways, some angled. STOL carriers such as HMS Invincible usually have a single through runway serving as take-off runway, landing runway and pad; they usually also have a ski jump because in practice they only operate STOVL and VTOL aircraft. Some 1930s carriers also had an additional take-off runway located on the hangar deck before the hangar, the rear portion of this runway being enclosed under the forward part of the main flight deck. A modern version of this type up-dated with catapults, ski jumps, arresters, etc. for use by newer aircraft and an "assembly line" system within a large hangar for fast landing, servicing and relaunching of large numbers of aircraft.

Apart from the above vessels, another carrier is known, this being a STOVL vessel without a landing runway: a large container ship on which containers stacked before the superstructure form a flight deck with a take-off runway, a pad and a ski jump. A STOVL vessel is an adequate carrier because even STOL vessels in practice only deploy STOVL and VTOL aircraft.

VTOL or helicopter carriers are also known: some such as the French Jeanne d'Arc configured with a large hangar aft, a large pad atop it, and lifts connecting those decks; a carrier for V/STOL-as-VTOL aircraft with no pad but using a device developed by British Aerospace to release and recover hovering V/STOL-as-VTOL aircraft has also been proposed.

Some VTOL vessels are not carriers but are other-role ships, usually small, configured in one of two ways: with a hangar on the main deck abaft the superstructure and a pad abaft the hangar; with only an aft pad. In contrast, CTOL, STOL and STOVL vessels are all large and, effectively, all carriers; this because all built or proposed have at least one of the following: a fore and aft flight deck with a superstructure beside it and therefore a wide beam; a heavy flight deck on the hangar roof and therefore a hangar of a construction sturdy enough to support it and a large hull to offset the resulting top-heaviness; a hangar enclosed in the hull and therefore a hull of wide beam; a hangar-deck with a take-off runway, that deck therefore being high above the waves; an in-line take-off runway and hangar or in-line take-off runway and superstructure and therefore a long hull; complex and/or heavy machinery like catapults, arresters and, especially, lifts.

Being large and expensive, these ships have to justify their purchase by having one or more of the following that make them even larger and/or more expensive: permanent air groups as large as the ships can carry and which, because the ships are large, are quite large; full and comprehensive servicing and maintenance facilities; large fuel and weapons storage capacity; an all-weather capability and therefore a high-profile but still stable and thus large hull. This overall expense means a number of other-role ships are not built. Carriers justify their expense and this forgoing of other ships with their air groups' potency; their expense, the forgoing of other ships and this potency in turn means carriers are both unriskable and a prime target to an enemy and therefore they are either or both: armed and/or armoured and therefore even larger and more costly; provided permanently with heavily-armed escorts--making them more attractive as targets as elimination of a carrier leaves its escorts without air cover. Carriers being unriskable, such weapons, whether fitted to carriers or to escorts, are largely restricted to defense as carriers must stay as far as possible from an enemy; their air groups effectively being the sole offensive weapon.

All this in effect means that carriers are single-role vessels: even if as heavily armed as a cruiser, they will not undertake tasks a more expendable cruiser can undertake. A balanced carrier navy, unless it is certain it will only go to war accompanied by allies, will have at least two of these expensive ships, their expensive air groups, their escorts, and other ships for independent operations. Such a navy with CTOL carriers can overwhelm any non-carrier navy and most land-based air forces. STOL or STOVL carrier navies are superior to navies not so equipped. These are the advantages of carriers; the disadvantage is expense, an expense that cannot be reduced because vessels with a runway above a hangar or a runway before a hangar, as noted, must be large.