Invincible (UK)
Despite the British government's continuous reductions in naval spending around 1964, the Royal Navy wanted to build new aircraft carriers to replace the aging Centaur-class aircraft carriers. Through unremitting efforts, the Royal Navy, citing the Soviet Union's expansion of nuclear submarine capabilities, secured a budget for the construction of an "anti-submarine cruiser" to replace the Tiger-class cruiser as the new command ship. This type of warship uses anti-aircraft missiles to carry out anti-air defense, carries out anti-submarine warfare with helicopters, and can undertake formation communication and command tasks.
The design work was organized by the Royal Navy Ship Building Department, but according to the internal requirements of the Admiralty, the new ship still had to have all the elements of the aircraft carrier, while installing modern guided weapons with complex electronic control systems to replace relatively simple and bulky conventional guns, focusing on the installation of advanced electronic equipment and command and control systems, while providing a huge internal space for the carrier-based helicopter and its maintenance workshop and spare parts compartment, and using gas turbines instead of steam turbines as power equipment. However, before the Naval Shipbuilding Department began the follow-up design, the CVA-01 fleet aircraft carrier plan proposed by the British Royal Navy in 1963 was completely rejected in the summer of 1966 because of the high cost of construction, so the Naval Staff Put forward an opinion on the "anti-submarine cruiser" in January 1967, believing that the new ship, as the future formation command ship, should have the basic facilities to command and control the anti-submarine formation composed of ships, aircraft and submarines, and could mainly carry anti-submarine helicopters. In accordance with the revision requirements, in order not to let the parliament find that the design is too similar to the aircraft carrier, the designers first completed a set of design schemes with a displacement of 12,500 tons, equipped with the "Sea Javelin" air defense missile system and 6 "Sea King" anti-submarine helicopters, and the overall design was presented as the layout of the bow missile, the stern superstructure and hangar, and the stern flight deck. After research, the designers found that if the number of helicopters was increased to 9, it would greatly improve combat efficiency, but this would require hangars and elevators on the lower deck, so the displacement would increase to 17,500 tons, and in order to provide a larger flight deck operating area, the superstructure needed to be moved to the starboard side, and the flight deck became an all-access deck. In order not to cast doubt on the part of the Parliament, they referred to the ship as a "command anti-submarine cruiser with an all-deck deck".
By 1968, Horace Law, the Secretary of the Naval Quartermaster General in charge of naval supplies, further proposed that the new ship could carry a Harrier vertical/stub fighter under development at the time to carry out regional air defense and anti-submarine missions. To this end, the designers also designed the all-through deck as a slide deck. The design work was not substantially completed until April 1970. When Peter Hill-Norton, the new British Secretary of the Navy, introduced the new ship design to the Ministry of Defence, he also tried to avoid the introduction of aviation combat power, but compared the ship as a command cruiser with the Tiger-class cruiser, and he proposed that the ship was equipped with a complex electronic control system, modern guided weapons and advanced command systems, as well as enough equipment to maintain and maintain anti-submarine helicopters. Most importantly, it uses a new type of gas turbine, which is particularly suitable for use in anti-submarine cruisers, as power equipment.
The Admiralty had planned to begin construction work as soon as possible, but due to britain's economic problems in the early 1970s, the budget for construction funds could not be allocated to the navy, and the delayed construction work was also changing the design work. In April 1973, the Admiralty finally signed a contract with Vickers Armstrong Shipbuilding Company for the construction of the first ship, and the new ship design had been finalized as a 19,000-ton displacement and 14 helicopter-carrying "heavy helicopter carrier cruisers". In mid-July of the same year, the ship was first started at vickers Armstrong's Inverness shipyard in Barrow, with the name "Invincible" at the same time, with a construction budget of 185 million pounds, but all shipboard missiles were reduced to "sea javelin" anti-aircraft missile devices on the bow, and the carrier-based aircraft retained only the "Sea King" anti-submarine helicopter.
In May 1975, after realizing that only aircraft carriers carrying fixed-wing aircraft could counter the Soviet maritime threat, the British government, which had always been extremely sensitive to aircraft carriers due to financial constraints, announced that it had agreed to equip these warships with naval versions of the Sea Harrier fighters, which meant that the designers had to re-modify the hull to accommodate more Sea Harrier fighters in the hangar. In order to enable a fully loaded "Sea Harrier" fighter to take off effectively, the fighter adopted the form of short take-off and landing, and added a sliding jump take-off runway with a length of 167.6 meters, a width of 12.2 meters, and a slight 7° deflection to the starboard side to allow the "Sea Javelin" missile launcher to open the bow. In May 1976 and December 1978, the Admiralty contracted the construction of one more ship on two separate occasions, named HMS Radiance and HMS Ark Royal.
Due to the light tonnage, the hull of the "Invincible" class has a shallow draft and a high dry port, and the bow column is slightly forward-leaning, using a square stern configuration. The island superstructure is located on the starboard side, and the bow arc forms a significant outward drift along the hull above the waterline, and in order to balance the eccentric weight of the island, this outer float is larger in the direction of the starboard side. The ship of this class was designed with the position of the Sea Javelin missile launcher in mind, so the bow building was designed in the open air with a slight angle on the deck. The long and narrow island building has key combat positions such as flight command rooms, bridges, combat command rooms, and communication rooms, and there are 7 decks below its flight deck, with a hangar and 4 cabins in the middle. The Invincible class is equipped with four Olympus TM3B gas turbines with a total power of more than 110,000 horsepower. However, due to the particularity of the overall layout of the aircraft carrier, the designers can only set the air intake on the side of the ship to ensure that when one of the ship's side is seriously damaged, each propulsion shaft can still have a main engine working normally, so the two main engines side by side are each imported from the left and right side of the ship. In order to ensure that the air inlet does not suck seawater, the designers installed a gas-water separator and filter at the inlet of the inlet with some complexity, relying on gravity and the filtration of the mesh to remove the seawater mixed in the inlet.
