The ''Illustrious'' class was a
class
Class or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used differentl ...
of
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...
of the
Royal Navy
The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...
that included some of the most important British warships in the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. They were laid down in the late 1930s as part of the
rearmament
Rearmament may refer to:
*German re-armament (''Aufrüstung''), the growth of the German military in contravention of the Versailles treaty (1930s)
*British re-armament, the modernisation of the British military in response to German re-armament ( ...
of British forces in response to the emerging threats of
Nazi Germany
Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...
,
Fascist Italy and
Imperial Japan
The also known as the Japanese Empire or Imperial Japan, was a historical nation-state and great power that existed from the Meiji Restoration in 1868 until the enactment of the post-World War II 1947 constitution and subsequent forma ...
.
The ''Illustrious'' class comprised four vessels:
HM Ships ''Illustrious'',
''Formidable'',
''Victorious'' and
''Indomitable''. The last of these was built to a modified design with a second, half-length, hangar deck below the main hangar deck. Each of these ships played a prominent part in the battles of the Second World War. ''Victorious'' took part in the pursuit of the
German battleship ''Bismarck'', ''Illustrious'' and ''Formidable'' played prominent parts in the battles in the
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
during 1940 and 1941 and all three took part in the large actions of the
British Pacific Fleet
The British Pacific Fleet (BPF) was a Royal Navy formation that saw action against Japan during the Second World War. The fleet was composed of empire naval vessels. The BPF formally came into being on 22 November 1944 from the remaining ships ...
in 1945.
The later two ships of the
''Implacable'' class were also built to modified designs to carry larger
air wings. and both had two hangar levels, albeit with a limited head room.
Design and concept
The ''Illustrious'' class was designed within the restrictions of the
Second London Naval Treaty
The Second London Naval Treaty was an international treaty signed as a result of the Second London Naval Disarmament Conference held in London, the United Kingdom. The conference started on 9 December 1935 and the treaty was signed by the parti ...
, which limited carrier size to an upper limit of 23,000 tons. They were different in conception to the Royal Navy's only modern carrier at the time, their predecessor
HMS ''Ark Royal'', and what may be described as their nearest American contemporaries, the
''Yorktown'' and
''Essex'' class carriers. The ''Illustrious'' class followed the ''Yorktown'' but preceded the ''Essex'', the latter being designed after the US abandonment of the Second London Naval Treaty and its tonnage limitations.
Where other designs emphasised large air groups as the primary means of defence, the ''Illustrious'' class relied on their
anti-aircraft armament and the passive defence provided by an
armoured flight deck
An armoured flight deck is an aircraft carrier flight deck that incorporates substantial armour in its design.
Comparison is often made between the carrier designs of the Royal Navy (RN) and the United States Navy (USN). The two navies followed ...
for survival, resulting in a reduced aircraft complement. Other carriers had armour carried on lower decks (e.g. the hangar deck or main deck); the unprotected flight deck and the hangar below it formed part of the
superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships.
Aboard ships and large boats
On water craft, the superstruct ...
, and were unprotected against even small bombs. However, the hangar could be made larger and thus more aircraft could be carried, but the differences in aircraft capacity between these carriers and their United States Navy (USN) counterparts is largely due to the some 100-foot-longer overall length of the US designs, and the USN's operational doctrine, which allowed for a permanent deck park of aircraft to augment their hangar capacity. ''Illustrious''s hangar was 82% as large as s, but ''Enterprise'' typically carried 30% of her aircraft capacity in her deck park. ''Indomitable''s two hangars were actually larger than ''Enterprise''s, but she carried fewer aircraft because she did not have a large permanent deck park. In 1944/45 RN carriers began to carry a permanent deck park of similar size to their USN counterparts, and this increased their aircraft complement from 36 to an eventual 57 aircraft in the single-hangar carriers, and from 48 up to 81 in the double-hangar, 23,400-ton ''
Implacable
Three ships of the Royal Navy have been named HMS ''Implacable'':
* The first , launched in 1795 as the French ship ''Duguay-Trouin'', was a 74-gun third-rate ship of the line. Captured by the British on 3 November 1805, she was renamed ''Implacab ...
'' design, compared to 90–110 for the 27,500-ton US ''Essex'' class.
In the ''Illustrious'' class, armour was carried at the flight deck level—which became the strength deck—and formed an armoured box-like hangar that was an integral part of the ship's structure. However, to make this possible without increasing the displacement it was necessary to reduce the overhead height of the hangars to in the ''Illustrious'' class hangars and in the upper hangar of the ''Indomitable'' and in her lower hangar; these compared unfavourably to the of the ''Essex'' class, in ''Enterprise'' and in ''Saratoga''. This restricted operations with larger aircraft designs, particularly post-war.
This armour scheme was designed to withstand 6" cruiser shellfire or 500 pound bombs (and heavier bombs dropped from low height or which struck at an angle); in the
Home
A home, or domicile, is a space used as a permanent or semi-permanent residence for one or many humans, and sometimes various companion animals. It is a fully or semi sheltered space and can have both interior and exterior aspects to it. H ...
and Mediterranean theatres it was likely that the carriers would operate within the range of shore-based aircraft, which could carry heavier bombs than their carrier-based equivalents. The flight deck had an armoured thickness of 3 inches, closed by 4.5-inch sides and bulkheads. There were 3-inch
strake
On a vessel's hull, a strake is a longitudinal course of planking or plating which runs from the boat's stempost (at the bows) to the sternpost or transom (at the rear). The garboard strakes are the two immediately adjacent to the keel on ...
s on either side extending from the box sides to the top edge of the main side belt, which was of 4.5 inches. The main belt protected the machinery, petrol storage, magazines and aerial weapon stores. The lifts were placed outside the hangar, at either end, with access through sliding armoured doors in the end bulkheads.
Later in the war it was found that bombs which penetrated and detonated inside the armoured hangar could cause structural deformation, as the latter was an integral part of the ship's structure.
Pre-war doctrine held that the ship's own firepower, rather than its aircraft, were to be relied upon for protection, since in the absence of radar, fighters were unlikely to intercept incoming attackers before they could release their weapons. Accordingly, the ''Illustrious'' class was given an extremely heavy anti-aircraft armament. The armament was similar to ''Ark Royal'' with twin 4.5 inch turrets (in a new "between-decks" or countersunk design) arranged on the points of a quadrant. The guns were mounted sufficiently high so that they could fire across the decks; de-fuelled aircraft would be stowed in the hangar for protection during aerial attack. The ''Illustrious Class'' were fitted with four
HACS
High Angle Control System (HACS) was a British anti-aircraft fire-control system employed by the Royal Navy from 1931 and used widely during World War II. HACS calculated the necessary deflection required to place an explosive shell in the loca ...
controlled High Angle Director Towers, for fire control of her 4.5 inch guns. ''Illustrious'' pioneered the use of
radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
to vector carrier-borne fighters onto attacking or shadowing aircraft, and a
Fairey Fulmar
The Fairey Fulmar is a British carrier-borne reconnaissance aircraft/fighter aircraft which was developed and manufactured by aircraft company Fairey Aviation. It was named after the northern fulmar, a seabird native to the British Isles. The F ...
fighter from ''Illustrious'' achieved the first radar directed kill on 2 September 1940.
Ships in class
Fate of the class
![HMS Victorious (R38) aerial c1959](https://upload.wikimedia.org/wikipedia/commons/4/4b/HMS_Victorious_%28R38%29_aerial_c1959.jpeg/1200px-HMS_Victorious_%28R38%29_aerial_c1959.jpeg)
All four early ships were hard worked during the Second World War, with ''Illustrious'' and ''Formidable'' suffering and surviving heavy damage. Like their contemporary , they fought a long and consuming war, and, despite significant overhauls and repair of battle damage, were worn out by 1946, and were scrapped in the mid-1950s. Due to a variety of factors including
Britain's dire post-war finances, and the consequent
reductions in the size of the Royal Navy post-war modernization was limited to just the last of the class; ''Victorious'', which was given a massive eight-year-long reconstruction between 1950 and 1957 (to enable her to operate
Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...
-era jet aircraft), was retired in 1968 after a minor fire. ''Indomitable'' was given an extensive refit, including new boilers, from 1948 to 1950, then served as flagship of the Home Fleet and also saw service in the Mediterranean. She suffered a hangar deck
petrol
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
explosion and fire in early 1953. She was placed in reserve after Queen Elizabeth II's October 1953 Coronation Review and was then scrapped in 1955.
[Friedman, p. 153]
See also
*
List of aircraft carriers
This list of aircraft carriers contains aircraft carriers listed alphabetically by name. An aircraft carrier is a warship with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft, that serves a ...
*
List of ships of the Second World War
This list of ships of the Second World War contains major military vessels of the war, arranged alphabetically and by type. The list includes armed vessels that served during the war and in the immediate aftermath, inclusive of localized ongoing ...
*
List of ship classes of the Second World War
The List of ship classes of World War II is an alphabetical list of all ship classes that served in World War II. Only actual classes are included as opposed to unique ships (which are still included if they were the only one of a class to be buil ...
Notes
References
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External links
Armoured aircraft carrier action and damage reports, 1940-1945ILLUSTRIOUS fleet aircraft carriers (1940–1941)
{{Authority control
Aircraft carrier classes
Ship classes of the Royal Navy