4

Aircraft Carriers

IN MID-1945 four of the new light fleet carriers of the Hermes class had been laid down with a further quartet nominally in the new construction programme. The latest fleet aircraft carrier design was the Malta class where there were plans to start building two ships, with a further pair again nominally part of the long-term programme. But only a matter of weeks after the end of the War two fleet carriers and four light fleet carriers were cancelled. By December the financial situation had deteriorated to such an extent that the final two ships of the Malta class, as well as the original Eagle of the earlier Ark Royal class, had to be abandoned. The Malta class were large ships, displacing some 46,000 tons. The original 1943 design had ‘closed’ hangars but by 1944 an assessment of American practice was to lead to an ‘open’ hangar being specified in spite of objections expressed by the Director of Naval Construction.

Considerable work had gone into the closed-hangar design. The first open-hangar design was 900ft long and again not a little effort went into developing this design but misgivings about the length of the ship resulted in the Board of Admiralty cutting back the length by some 50ft. Yet more design effort was wasted. The advantage of the open-hangar design was the ability to get aircraft warmed up on the hangar deck and thus launch them more quickly, which was felt to be crucial by the airmen. The advent of the atomic bomb placed a new complexion on the subject and the Malta class was destined to be a dead end in design terms. The ability to close down the ship and wash off exposed surfaces to protect against radioactive fallout became vital and counteracted any advantages of an ‘open’ hangar. Furthermore, the introduction of jet aircraft, which needed less time to warm up than piston-engined ones, made an open hangar less necessary.

The 1952 Fleet Aircraft Carrier

The aircraft carrier fleet of the 1950s and early 1960s was initially to be provided by Eagle and Ark Royal the four ships of the Hermes class then under construction, and the reconstruction of the six wartime fleet aircraft carriers. However, by June 1952 it was clear that the reconstruction of the Victorious was proving difficult and the Board of Admiralty came to the conclusion that it was the wrong policy to spend money on modernising the old carriers. Instead a new design was to be developed with a view to completing the ship in 1958. Steel for the new ships, then in short supply, was to be found by scrapping Formidable and the early ‘Hunt’ class escort destroyers.¹

The Ship Design Policy Committee first considered the development of a new aircraft carrier design in April 1952. It was suggested that the ship should displace 55,000 tons, have a flight deck 1000ft long, be capable of 30kts ‘deep and dirty’, and have an economical cruising speed of 20 to 25kts. The endurance wanted was 6000 miles at 22kts whilst the carrier was to handle 80–90 aircraft with a weight of 60,000lbs. There was talk of a ‘skew’ landing deck. It was suggested that the ship be laid down in 1956.²

In July 1952, with the Board of Admiralty clearly supporting development of the new carrier, the requirements were further debated. The ship now had to be capable of carrying an aircraft the size of a Canberra bomber weighing 70,000lbs, with a length of 65ft and a 70ft wingspan. A single hangar with a height of 22ft was required, a considerable advance on the 17ft 6in built in to the Ark Royal design. It was to have an area of 50,000–55,000ft². Three catapults were specified and ideally four were wanted. The flight deck was still to be 1000ft long so that the Canberra, Scimitar and successors could be operated.

This ambitious specification meant that docking was going to be a major problem. No. 10 Dock at Devonport was the only Admiralty-controlled dock capable of reliably taking the Eagle and Ark Royal and it was said that had the aircraft carrier Malta been built then a new dock would have been needed to accommodate her. The draught of the new vessel had to be limited to 33ft on the insistence of the Director of Naval Construction. The speed of the ship was now to be 32kts clean in temperate waters. Endurance and economical cruising ranges showed no change from the original specifications. There was to be a capacity of 750,000 gallons of aviation fuel including 250,000 gallons of AVGAS. The advent of jet aircraft operating provided one potential advantage, for jet fuel was less flammable, which meant that stowage arrangements were easier to design as safety precautions took up less space. Protection was 2in plate to the waterline but the full specification was to be worked out at a later date. The main anti-aircraft armament was to be the new 3in/70 cal. twin mounting, whilst the main radar array was a pair of Type 984, then under development.³

By September 1952 the parameters of the ship were: length 815ft, hull beam 115ft, a figure which the angled flight deck, by now a firm feature, extended to 160ft. The ship displaced some 52,000 tons; four sets of machinery were to produce 200,000shp to give a speed of 30kts with the ship ‘deep and dirty’ in the tropics. The flight deck was to have 2in NC protection with the structure of the ship being largely welded. The size of the design, although now less than in the first designs, meant that the only dry docks capable of accommodating the class were No. 10 Dock at Devonport, the Gladstone Dock at Liverpool and No.1 Dock at Gibraltar. The tentative programme at this time was:

1952 Fleet Aircraft Carrier. Four versions are illustrated. The engine/boiler/magazine layout as illustrated in Sketches ‘B’ and ‘D’ was preferred. Note the angled deck, a feature tested in the light fleet carrier Triumph in February 1952.

(Drawing by John Roberts from original in NMM ADM 138/818)

1 September 1952 – Preliminary Studies complete.

1 December 1952 – Sketch Design to Board and commence Building Drawings and Specifications.

1 December 1953 – Building Drawings to the Board.

1 January 1954 – Order Ship.

1 May 1954 – Lay Down Ship.

1 July 1955 – Steel Deliveries complete.

Mid 1956 – Launch ex-Machinery or mid 1957 launch with Machinery.

31 December 1958 – Complete Ship.

This programme quickly saw slippage, with the preliminary deadlines not being met. Early developments in the life of the ship showed interesting innovations, with two funnels being preferred, and hinged funnels also being considered. An angled deck on the starboard side was also investigated but abandoned in favour of the original portangled configuration. By June 1953 the design staff were clearly under pressure, indicating potential problems in evolving the design of such a complex warship. Other new projects also underway or planned included a new cruiser, two designs of fast escort each with different hulls, the Type 42 coastal escort, the stage two aircraft-direction frigate, a medium fast patrol boat and a new midget submarine. There were also industrial considerations. The only three shipyards capable of building the new aircraft carrier were John Brown, where No. 4 slip was available in January 1955, Cammell Laird’s No. 4/5 slip, available in June 1955, and Harland and Wolff’s No. 14 slip, available in June 1953 but earmarked for a liner. Important criteria in the choice of contractor would have been the availability of electricians and the attitude to welding in the yard. There would also have been problems in manufacturing the machinery, for had the ship been built with the aim of completing her in 1958, it would have had to have been ordered in October 1952, which was clearly impossible.

By April 1953 doubts were being expressed about whether building the large fleet carrier, two of which were included in the long-term programme, could be justified, and it was agreed to aim for smaller carriers. The cost of each ship was said to be £26 million. The end finally came in July 1953 when the ship was cancelled as part of an evolving Radical Review. However, development of the machinery – by now designated Y300 with each unit now expected to produce 45,000shp – continued at the request of the Engineer-in-Chief, who clearly had future projects in mind. The design had reached the Sketch Staff Requirement stage when it was abandoned. The dimensions were unchanged apart from the beam where the width on the waterline had been increased to 116ft. The deep draught was 33ft 6in with the deep displacement now 53,150 tons. There were two catapults, one with a 200ft stroke, the second with a 150ft stroke. The maximum aircraft take off weight was to be 60,000lbs with a maximum landing weight of 45,000lbs. The aircraft complement was undecided but calculations were based on a complement of 12 strike aircraft × 33,000lbs, 33 fighters × 22,000lbs and 8 anti-submarine aircraft × 16,500lbs. The hangar height was the standard 17ft 6in, and the main anti-aircraft armament was six 3in/70 cal. twin mountings. Protection of both the hangar deck and sides was 2in NC with 3½in NC armour for the magazines and steering compartment. Group weights were:

	Tons
Hull structure	18,460
Hull fittings etc	9855
Armour and protection	4665
Equipment	2479
Aircraft equipment, weapons and fuel	5725
Armament	987
Machinery	4125
Reserve feed water	280
FFO and DIESO	6400
Margin	174
Deep Displacement	53,150 tons.4

The 1954 Medium Fleet Aircraft Carrier

The demise of the large fleet carrier did not mean that interest waned in the provision of new ships. As early as May 1953 the possibility of constructing cheaper carriers was raised, with thoughts that a ship of some 20,000 tons could be produced. By February 1954 it was found to be difficult to accommodate the necessary requirements within a 24,000-ton hull. The Director of Naval Construction commented that a larger carrier would give a steadier flight deck, a more flexible layout of aircraft equipment, better aircraft control arrangements and greater scope in making allowances for future aircraft development. Nevertheless, in November 1954 a 28,000-ton design was included in the book of studies produced for the Sea Lords. The design had a similar capability to Hermes and was able to operate 38 aircraft which could include 12 Scimitars (N.113), 12 Sea Vixens (DH.110), 5 Gannets, 4 airborne early-warning aircraft and 2 search-and-rescue helicopters. The deck was fully angled. The defensive armament had to be twin Bofors with MRS3 directors as it was impossible to accommodate the 3in/70 cal. mounting. Machinery consisted of a two-shaft arrangement with 50,000shp per shaft, which gave a speed of 28.4kts ‘deep and dirty’. Endurance was 5500 miles at 20kts under operational conditions. However, the Director of Naval Construction did not consider the design to be a balanced one, particularly as regards the defensive armament. On 22 December 1954 the Sea Lords concluded that the ship seemed too small for a big carrier and too big for a small carrier. The project then died.⁵

CVA-01, also known as Project 35. The drawing illustrates the design in March 1963. There were many modifications made but the basic layout does not seem to have changed. The deck plans show the angled and parallel deck layouts as at December 1962. The parallel layout was adopted.

(Drawing by John Roberts from original in NMM ADM 138/888)

Contemporaneously with the smaller carrier studies, consideration was being given to the design and construction of a larger 35,000-ton ship. By May 1954 one ship was included in the ongoing amended £1610 Million Plan – a figure first settled upon in the 1953–4 Estimates – with the aim of producing Staff Requirements in the autumn of 1954, laying the ship down in August 1957 with completion in May 1962. A second ship was also envisaged. The cost of each new carrier was very approximately placed at £18 million. One interesting aim was embodying suitable characteristics to enable the ships to be adapted for the operation of vertical take-off aircraft – a far-sighted ambition included as a result of his first visit to Bath by Lord Louis Mountbatten, the new First Sea Lord. The design was duly included in the Book of Studies prepared for the Sea Lords, the ship being considered the smallest carrier that would operate modern aircraft in reasonable numbers, being regarded as ‘in effect a general purpose carrier which while not being so large as to be wasted in the trade protection role, could carry a considerable strike force as an alternative when required’.

She could operate 47 aircraft, a typical mixture of types including 12 Scimitars, 12 Sea Vixens, 8 Gannets, 9 Buccaneers, 4 airborne early-warning aircraft and 2 search-and-rescue helicopters. The defensive armament consisted of four twin 3in/70 cal. with MRS3 directors and a secondary Bofors armament provided below the flight deck on the transom. Some 2700 tons of protection was worked into the design, the hangar being protected at the top by 1¾in plate, the sides being 1¼Ain. There was 3in side armour by way of a citadel, whilst the top of the citadel and vital compartments in the island benefited from 1½in protection. The ship had an angled deck and two catapults. The machinery was to be a three-shaft arrangement with 45,000shp on each shaft which produced a speed of 29.9kts ‘deep and dirty’. Endurance was 5000 miles under operational conditions. The design was still evolving at this stage, with the armament and the machinery subject to discussion. In the latter case a twin-shaft arrangement was being considered, each unit having greater power. It was expected that weight would be saved. The ship would have accommodated a crew of 300 officers and 2100 ratings.⁶

Development of the design continued throughout 1955 with Staff Requirements being discussed and as late as 1956 outline drawings of a fleet carrier were shown at a meeting in Bath. How the project evolved thereafter is not known but three 45,000-ton aircraft carriers were included in the 1959–60 Long Term Costing. They were to complete in the 1970–1, 1971–2 and 1972–3 financial years. This project was, however, succeeded by CVA-01.⁷

The Fleet Carrier – CVA-01

In November 1958 the Director of Naval Construction drew attention to the age of the aircraft carrier force. At that time they were expected to end their lives in: 1972 (Victorious), 1973 (Eagle and Centaur), 1974 (Albion), 1975 (Ark Royal) and 1980 (Hermes). Little seems to have been done immediately but by January 1960 the Fleet Requirements Committee was giving consideration to the size of the ship. A displacement in the range 45,000–50,000 tons was envisaged. The issue was also discussed on 19 January by the Board of Admiralty, where the First Sea Lord expressed the view that the Government of the day would feel able to afford no more than four new carriers. By June 1960 the Ship Characteristics Committee had drawn up a timetable of the approach required; an abbreviated version is set out below:

Staff Requirement approval needed – end of 1961.

Approval of the Sketch Design – end 1962.

Provisional order including main machinery – early 1963.

Approve building drawings and complete specification – early 1965.

Confirm order – 1965.

Lay down ship – mid-1965.

Launch ship – mid-1967.

Ship in service – mid-1970.

Operational – mid-1971.

By November 1960 the Fleet Requirements Committee were considering a range of six studies with deep displacements between 42,000 tons and 68,000 tons. A fleet of four 42,000-ton ships was estimated to cost £180 million, whilst four 55,000-ton carriers were estimated at £240 million, but these figures were regarded as very tentative. There were key advantages in size, for the 55,000-ton ship had an aircraft capacity which was 80 per cent greater than the smaller vessel, and was expected to be suffer less interference to flying operations due to weather and have a lower aircraft accident rate. Doubts were expressed about the value of the smaller carrier which could accommodate 27 Buccaneer or Sea Vixen aircraft as opposed to 38 in the 48,000-ton ship or 49 in the 55,000-ton carrier. The Board of Admiralty concluded in January 1961 that a ship of at least 48,000 tons would be needed. The aircraft complement indicated two main roles for the ship: firstly to act as a strike carrier, a function which included attacking enemy airfields; and secondly to provide air defence for the fleet. Other functions included supporting radar early-warning aircraft and, a later addition, the embarkation of anti-submarine helicopters.⁸

Discussions between the Naval Staff Divisions duly proceeded on the basis that the ship would displace about 50,000 tons. Some forty design studies were made, whilst the Forrestal of the United States Navy and the Foch of the French Navy were also considered. The former had to be ruled out as too expensive, whilst the latter was thought to be unstable and too small to carry enough aircraft to make the ship worthwhile. A design study known as ‘A1/1D’ emerged early in 1962. Length overall was 890ft, beam at the waterline 118ft, the maximum width of the flight deck being 177ft with displacement 50,000 tons deep. On 2 April 1962 the Board of Admiralty considered the merits of the design in some detail. They decided that a quick study be made of a carrier of up to 60,000 tons capable of embarking more aircraft (including the possibility of carrying more aircraft on deck), the types of aircraft which the carrier could carry, and a comparison between the new ship and the modernised Eagle. The implication of using commercial docks in the early life of the ship was also considered.

Artist’s impressions of CVA-01 as the design appeared in the summer of 1965. Note the slight angle (3½°) of the flight deck, Type 988 Anglo-Dutch radar, deck-edge lift, opening to hangar aft, and Sea Dart launcher on the quarterdeck. The aircraft are Phantoms and Buccaneers, with a Sea King helicopter parked aft.

(Author’s collection)

By May 1962 another series of five design studies emerged in response to the Board Minute, with deep displacements ranging from 50,000 tons to 58,000 tons. The studies were presented to the Board of Admiralty, who after deliberation decided that ‘Design 53’ should be developed as the replacement for Victorious as the best compromise available in the circumstances. The cost of the ship was constrained to £55–60 million at current prices, with the added proviso that no additional equipment could be added which increased this cost. There was, however, one dissenting voice, namely the Civil Lord of the Admiralty, Lord Carrington. He suggested that the Board give serious consideration to a design of about 40,000 tons carrying 24 aircraft costing around £43 million, an ominous portent for the future. The new design displaced 53,000 tons and carried 35 aircraft and 5 anti-submarine helicopters. Length overall was 920ft, beam at the waterline 120/122ft, the maximum width of the flight deck being 180ft.⁹

Development of the design now proceeded, but complications due to a stretched budget soon emerged. By May 1963 there were still four ships in the Long Term Programme, but CVA-01 had been put back 10 months with her planned sister-ships all delayed by 6 months. The main cause was the addition to the building programme of four Polaris ballistic missile submarines ordered in April 1963. Expenditure of £1.6 million had been agreed to fund development of the design, but from October 1962 difficulty was experienced in getting the Treasury to approve individual projects within this ceiling, creating problems in maintaining the design effort as a result of this parsimony. By July 1963 the Sketch Design had been developed sufficiently for it to be placed before the Board of Admiralty. The length of the ship had increased from 870ft to 890ft at the water-line, the overall width of the flight deck rising from 180ft to 189ft. The ship had three shafts with the machinery developing 135,000shp, which gave a speed of 28kts and an endurance of 6000 miles at 20kts ‘deep and dirty’.

The aircraft complement was 30 strike and fighter aircraft, which initially would be the Buccaneer and Sea Vixen with the planned variable-geometry (‘swing-wing’) aircraft being designed to meet Operational Requirement 346 being embarked later. Four early warning aircraft, 2 search and rescue helicopters and 5 anti-submarine helicopters were also to be part of the complement. Aircraft weighing up to 70,000lbs could be operated, with two 250ft catapults and two lifts (70ft · 32ft) installed. The angled deck in ‘Study 53’ was originally 7°, while the sketch design had a parallel deck with an angle of 4°. The 3D surveillance radar, originally to be two systems, was reduced to one because of space and interference problems. Electrical power output was increased from a planned 18,000 kW to 20,200 kW. Both designs had a defensive armament of one Ikara anti-submarine system and one CF299 Sea Dart anti-aircraft missile launcher. With an eye to the future there were four take-off positions for VSTOL aircraft. On 17 July 1963 the Board of Admiralty approved the Sketch Design and Staff requirements and decided that a price of £58 million should be shown in the long-term costings. On 30 July the Cabinet agreed that the aircraft carrier fleet be maintained at three vessels in the 1970s, a reduction of one ship from the earlier planned levels and that the new aircraft carrier should be built to replace the Ark Royal.

Pressure on the project was intense throughout the early months of 1963, with the Chief of the Defence Staff, Admiral of the Fleet The Earl Mountbatten of Burma, attempting to resolve the now bitter dispute between the Admiralty and Air Ministry over the planned new aircraft carriers. The project survived but various ideas were explored which investigated how the Royal Navy would operate without aircraft carriers. One option, a 20,000-ton offshore support ship, was considered to the extent that Draft Staff Requirements were drawn up, but the idea was not considered practical.¹⁰

Building a new aircraft carrier of this size and complexity was not going to be a straightforward operation. There was, firstly, the physical problem at the shipyards, where there were no berths which could meet requirements without expenditure on widening and/or dredging fitting-out berths. There was also a perceived technical problem to resolve, for one-third of the structure was to be built with QT35 steel which required specially-trained welders. This steel was used in nuclear submarines and here work was said to have been placed with subcontractors because the shipbuilders could not find welders of the right quality. In practice, it was found that a 2-week training course was all that was needed to develop the necessary skills. Subcontractors could well have been used to make up a numerical shortage of welders. It was also believed that all work with QT35 had to be done under cover. In fact early nuclear submarines with this steel were built in the open.

Another problem was that none of the shipyards possessed sufficient drawing office capacity and even combining the staffs of two shipyards such as John Brown and Fairfield meant that virtually all the draughtsmen employed in the hull and engineering sections would be needed, and there was still a shortfall in electrical draughtsmen. When it came to construction there were again going to be difficulties. The worst area was the provision of electrical fitters, where the requirement was estimated to be 800 men whereas in late 1964 the largest number employed in any one yard was 338 at Harland & Wolff. There were also worries about the quality of the management at the shipyards where better planning, inspection and quality control was deemed necessary. Another requirement was a new dry dock to take the ship at Portsmouth where planning was progressing but there was no approval to take it forward beyond this stage.¹¹

The project progressed and in April 1964 there were even thoughts that the Royal Australian Navy would buy one of the class. Had this occurred the draft programme would have been to order CVA-01 and the Australian ship in the last quarter of 1966, with the completions seen in the third and fourth quarters of 1973, CVA-02 being ordered in late 1969. Changes to the design inevitably occurred. The Ikara system was deleted in February 1965 when a role as a commando ship was also considered. At that time there were long-term plans to build three commando ships to replace and enhance the capacity currently provided by the converted aircraft carriers Albion and Bulwark.¹²

The design of CVA-01 incorporated many novel features. She has been described as a ‘furniture van’ with a novel light structure and until very late in the day had no armour, not even over the magazines, but she did possess new, effective torpedo protection based on work at the Naval Construction Research Establishment. The power needed to achieve 27–28kts was thought to be too much for a two-shaft layout in Bath (but not by the propeller designers at Haslar), so three shafts were chosen in spite of worries about vibration. This arrangement enabled one unit to be shut down for maintenance while maintaining a fairly high speed on the other two engines. The steam plant was novel, operating at 1000psi at 1000°F. The electrical distribution system was at 3.3 kV with step-down transformers, also new to the Royal Navy. The steam catapults were longer than in existing carriers and required as much steam as the propulsion plant. Bigger boilers were therefore needed. New hydraulic arrester gear and a scissors lift were incorporated. The flight deck layout was another new feature, the small angle finally being 3½°. Outboard of the island on the starboard side was a wide passage for moving aircraft aft. There were also doors at the after end of the hangar opening on to a quarterdeck to enable aircraft engines to be run in the hangar. The size of the island proved a difficult problem to solve, for early studies incorporated two surveillance radars. The matter was resolved when one Anglo-Dutch ‘Broomstick’ Type 988 radar was specified.

Another problem was the lack of staff in Ship Department: the number required was 30 rising up to 80, but the maximum number employed was 45, with inevitable penalties. Very late in the day it was decided to incorporate better protection. This ranged in thickness from 2½in at the magazine sides, 2in at the Sea Dart magazine sides and ends, to 1½in at the ship’s sides, with lin protection being given to the hangar. The result was an increase in displacement from the constrained 53,000 tons to 54,500 tons. The ship was, however, still said to displace 53,000 tons in ‘average action condition’. The Project Managers were J C Lawrence (1958–62) and L J Rydill (1962–7), and the latter was particularly concerned about the extent of the new features and equipment incorporated in the design. Not only new features and equipment were specified but also weapons such as the untried and developing Sea Dart missile and aircraft such as the new variable-geometry project. A particular problem was the association of displacement with cost, which was proving a fallacy as complex (and expensive) solutions were accepted to save weight to keep the ship within the agreed displacement of 53,000 tons.¹³

The first ship was to be named Queen Elizabeth, with Duke of Edinburgh being reserved for the second member of the class. The Board of Admiralty approved the final design of CVA-01 on 27 January 1966, at the same time warmly congratulating the DG Ships and his staff who were responsible for the design. A Legend had been drawn up in December 1965. There were no changes to the length of the hull but the length overall including the bridle arrester boom was 963ft 3in. The extreme breadth of the ship was 231ft 4in. The weight of the hull and the protection were quoted as one item at 33,900 tons. The aircraft complement was now 36 Buccaneers or Phantoms, 4 early warning aircraft, 5 anti-submarine helicopters and 2 search-and-rescue helicopters. Orders for long-lead items costing £3.5 million had been placed in spite of Treasury procrastination, of which £1.5 million would be nugatory expenditure if the project did not go ahead. Less than a month later, with detailed plans ready for dispatch to the shipbuilders, the aircraft carrier was cancelled. The event was traumatic, and the whole structure of the Royal Navy came under review with the formation of the Future Fleet Working Party. Although desirable, this class of aircraft carriers was more than the nation could afford, since building the ships was but 20 per cent of the through-life cost of operating the vessels.¹⁴

The Escort Cruiser

The first studies for a new helicopter ship to carry 22 helicopters were probably completed in 1959–60. The result was a series of designs, the largest being a vessel displacing 19,000 tons. Clearly it was going to be impossible to build such a ship within existing budgets, so the requirement was scaled back to a ship capable of operating 6 (later 8) helicopters. Studies in 1960 now concentrated on ships with speeds of 26kts ‘deep and dirty’ and armed variously with a twin 3in/70 cal., US Tartar or British Sea Slug missiles. Three series were produced.

In Series 6 ‘Study 6C’ displaced 5400 tons deep with a waterline length of 430ft, carrying 8 Wessex helicopters and armed with a twin 3in/70 cal. mounting. ‘Study 6D’ substituted a Tartar missile system for the gun mounting. The complement of both ships was 50 officers and 400 men. ‘Study 6E’ was equipped as ‘6C’ and ‘6F’ as ‘6D’ but the ships were fitted as guided-missile destroyer style flagships. The crew increased to 61 officers and 534 men, with the result that the length of both studies increased to 460ft and displacement to 5900 tons.

1960 Escort Cruiser. This early Series 9 study illustrates the design with a twin Sea Slug launcher placed forward of the bridge structure. The flight deck is located aft of the superstructure with the hangar for helicopters located in the hull of the ship.

(Drawing by John Roberts)

1960/61 Escort Cruiser. In this later Series 21 study a through-deck layout has been adopted and the Sea Slug launcher moved aft. A twin 4.5in Mark VI mounting is situated on the ‘island’ and the hangar is located within the hull.

(Drawing by John Roberts)

The Series 9 studies were larger ships armed with 28 Sea Slug missiles, 12 ready for use and 16 stowed broken-down. ‘Study 9C’ was 485ft long with a displacement of 6400 tons. The twin-shaft turbine machinery produced 36,000shp. The hangar height was 16ft 6in with the decks capable of handling an all-up weight of 12,600lbs. In ‘Study 9D’ the hangar height was increased to 18ft 6in with the strength of the deck increased to take a 22,0001b helicopter. In ‘Study 9E’ the superstructure was placed to starboard as an island, with the flight deck extended to port by means of a sponson. Displacement increased to 6730 tons. Four helicopters could be operated simultaneously. Series 6 and 9 were designed to destroyer standards for maintenance, complements and endurance.

Flagship cruiser variants were produced in Series 21. ‘Study 2 ID’ had an armament as in Series 9 but was fitted with some splinter protection. Length was 535ft, the machinery produced 40,000shp and displacement was 8350 tons. ‘Study 21H2’ had an island structure, a twin 4.5in Mark VI sited above the flight deck facing aft, and an increase in freeboard forward to ensure maximum dry-ness for the Sea Slug launcher. The missile stowage was increased to 12 ready-use and 32 broken-down missiles. Displacement was 9500 tons. ‘Study 21J2’ had two twin 4.5in mountings facing aft, displacement rising to 9700 tons. In ‘Study 2IK’ the guns were mounted forward and the Sea Slug launcher aft. Length increased to 560ft and deep displacement to 9860 tons. Missile stowage, however, dropped to 28 rounds and the arrangements were regarded as awkward. The final variant, ‘Study 21L2’, was the same as ‘Study 21J2’ with an island superstructure but with machinery power increased to 60,000shp to give 28.5kts ‘deep and dirty’. Displacement rose to 10,250 tons, with the waterline length being 550ft. All the cruiser studies had an endurance of 4500 miles at 20kts.¹⁵

The largest cruiser study was developed, for by December 1961 the First Sea Lord was presenting details of the latest design to the Chiefs of Staff Committee. The ship now displaced 13,250 tons, with length at the waterline was 610ft and beam 73ft. Machinery producing 60,000shp gave the ship a speed of 28kts whilst endurance was 5000 miles at 12kts. The main armament remained Sea Slug with an outfit of 28 missiles. There were also two Sea Cat short-range missile launchers and a twin 4.5in Mark VI. Nine helicopters were operated. The complement was 106 officers and 970 ratings. Cost was in the order of £19.25 million, with the first ship to be ordered early in 1964 and completed by mid-1967. The ships were required for the effective deployment of anti-submarine helicopters and guided-missile air defence. They also had the ability to operate as fleet units or independently for long periods. Four ships were placed in the long-term programme, part of the cost being found by deleting the last two units of the ‘County’ class (DLG 09 and 10). Two of the Tiger class cruisers were also to be replaced.

By July 1962 the ships had been redesigned. The alterations were substantial, for 4 Chinook-type helicopters were to be carried. The weapons were also modified, with two launchers for the new Sea Dart (CF299) guided missile and the Ikara anti-submarine weapon system installed. There was also to be accommodation to enable 700 troops to be embarked in an emergency. The displacement was reduced to 10,000 tons and the cost to £16.5 million.¹⁶ The decision to purchase the four Polaris submarines, however, resulted in the deferment of the escort cruisers but not their deletion from the long-term plans. The cause was not only financial but also inevitable design delays due to resources being concentrated on the new carrier and the Polaris SSBNs. The plan was now to bring them into service 10 years after conversion of the Tiger class, which was authorised when the escort cruiser programme was delayed.¹⁷

This new class was destined not to be built, for in February 1966 the new aircraft carrier CVA-01 was cancelled and it was decided to review the whole structure of the fleet. Nevertheless, they did have an influence on the studies undertaken by the Future Fleet Working Party. One lesson learned from this affair is that constraints on size do not necessarily lead to a reduction in cost. The new aircraft carriers being designed in the first decade of the twenty-first century are being made bigger to help ‘reduce’ the price of the ships.

The Invincible Class

The cancellation of CVA-01 and ultimately the decision to abandon conventional fixed-wing aircraft flying from carriers in the Royal Navy was to lead to a major reappraisal of the make-up of the fleet. Early in 1966 the Future Fleet Working Party was formed to consider the problem and provide the Board of Admiralty and the Government with recommendations.

The studies included a commando cruiser, initially described as an escort cruiser/commando ship. The design probably owed some of its characteristics to the earlier escort cruiser designs, which had remained in the long-term construction programme up to the time of the review. The primary tasks of the new design were ASW helicopter operation, the transport and loading of an embarked force, the provision of a self-contained air strike/reconnaissance capability, some fighter defence and, lastly, command and control of a naval task force or an amphibious operation. In June 1966 there was talk of producing six ships, the first vessel being accepted in June 1975. Studies were produced with the superstructure forward, the superstructure aft and a conventional aircraft carrier arrangement. It was concluded that the traditional arrangement was clearly superior to the alternatives. The helicopters carried would have been the Sea King for both the ASW and commando roles, whilst the fighter requirement was to be met by the VSTOL Kestrel, the immediate ancestor of the Harrier and Sea Harrier. It was envisaged that gas turbine propulsion would be provided. The main weapons were the Sea Dart and PX430 (later named Sea Wolf) anti-aircraft missiles. The big Anglo-Dutch ‘Broomstick’ Type 988 radar was to be installed. By August 1966 an increased complement was being called for in the 16,000-ton design, the numbers being increased from 1390 to 1712 officers and men. The effect of this demand was that length increased by 30ft, the beam by 1ft, draught by 6in, displacement by 1500 tons and cost by £1.5 million to £31.5 million.¹⁸

Opposite: Illustrious on 23 February 1983, with the full normal complement of Harrier aircraft and Sea King helicopters on deck. The Sea Dart installation, with its blast deflector, is prominent forward, with the Vulcan Phalanx CIWS to starboard.

(D K Brown collection)

Future Fleet Working Party 1966 – Large Ship Studies.

Eight studies were produced of cruiser carriers, cruisers and a commando ship. Features will have appeared earlier in the escort cruisers, which were still in the forward programme in 1966. They were also an influence on the Invincible design but only indirectly as the design of this ship started afresh. (PRO DEFE 24/238)

Cruiser Carrier – Study No 1. Design capable of operating helicopters and V/STOL aircraft with full command and control facilities. The ship had a commando capability.

Cruiser Carrier – Study No 2. Design has limitations effecting the operation of both helicopters and V/STOL aircraft. Ship has full command and control facilities and a commando capability but there is less accommodation.

Cruiser Carrier – Study No 3. General capabilities as Studies Nos 1 and 2 but poor layout for operating helicopters and V/STOL aircraft. Hangar arrangement was bad because doors would have needed an air lock. Machinery arrangement was not satisfactory because machinery and gearing could not have been placed in line.

Commando Ship – Study No 4. A ‘cheap’ ship constructed to merchant standards. Internal volume comparable with USS Iwo Jima.

Cruiser – Study No 5. A ship intended to operate 6 SH3D (Sea King) helicopters with full command and control facilities.

Cruiser – Study No 6. A ship intended to operate 9 V/STOL aircraft with full command and control facilities.

Cruiser – Study No 7. A ship capable of operating 9 SH3D helicopters and 4 V/STOL aircraft, with full command and control facilities.

Cruiser Carrier – Study No 8. As study No 1 but with commando capability removed.

The results of these deliberations were produced in a report for the Board of Admiralty entitled ‘Ship Design Recommendations and Studies’ which duly appeared in August 1966. Included were four cruiser carrier studies, three cruiser studies and a commando ship. Other details and drawings appear in Chapter 6.¹⁹

The Board of Admiralty discussed the Future Fleet Working Party report in October and November 1966. The idea of a combined cruiser and commando ship was rejected, the intention now being that the cruiser should be kept to the smallest size consistent with its primary function of command and control. It was estimated that the displacement of the ship would be about 10,000 tons. There was also opposition to the inclusion of Kestrel VSTOL capability with the majority of the Board regarding this option as not cost effective. The Deputy Chief of the Naval Staff, however, had reservations on this point. In his view the cruiser required a better offensive capability against surface ships and an increase to 13,000 tons would not only keep the option open but would also provide a better potential to exploit any future VSTOL developments. Final decisions were not taken, with Dennis Healey, the Minister of Defence, who was present at the meeting indicating that further consultations were necessary.²⁰

The Cruiser. These three studies produced in 1968 were the first options considered to meet a requirement that was to lead eventually to the Invincible class. Study 21 was a half-deck solution with the hangar in the superstructure. Studies 22 and 23 were through-deck ships with an internal hangar. Study 23 included provision for a ‘bottom bounce’ sonar, hence the slight increase in dimensions. Study 23 was chosen for development with the provision of V/STOL capability being investigated.

(Drawing by John Roberts from original in PRO DEFE 24/388)

The attitude of the Treasury at this time was far more supportive of the plans then envisaged than compared to the attitude shown to the big aircraft carrier. The deliberations of the Future Fleet Working Party were regarded as sensible at this juncture and there were still six cruisers envisaged in the long-term costings. These were now being seen as a development of the Type 82 destroyer, with command facilities and helicopters but no Ikara ASW system, displacing around 10,000 tons and costing £30 million. The first ship was expected to enter service at the end of 1975.²¹

By July 1967 Ministers had approved that planning of the fleet of the 1970s and beyond should be based on three new classes of warship: a frigate to succeed the Leander class, a destroyer to carry Sea Dart, and a cruiser to succeed the converted Tigers. Capabilities of the cruiser were to be force command, control of shore-based aircraft, and contributions to area ASW defence and to area air defence. Based on these requirements, the Staff Target was produced and endorsed by the Operational Requirements Committee in December 1967 (NST 7097). The Director of Naval Construction duly produced a series of three studies in January 1968:

It was decided that the Naval Staff requirement should be based on ‘Study 23’. Also decided was that a VSTOL capability should be investigated within a total mix of 12 aircraft and that the cost bracket of the studies should be within the range of £32 million to £38 million. The design was still very much in its early stages and there were many problems to solve. Propulsion options were either four Olympus gas turbines on two shafts, two Olympus and two Ruston diesels, four boilers and two sets of steam turbines, or four Ruston diesels with two on each shaft. The number of Sea Dart missiles to be carried was debated and here it was concluded that 22 would be an acceptable minimum. Other issues to be resolved included helicopter numbers, the provision for future aircraft, the avionic and weapon fit, speed and endurance. Performance in the ranges 24–28kts, 5000–7500 miles at 18–20kts was debated. Further matters to resolve were hull configuration, provision of a high grade hull-mounted sonar, degree of self-support including storing intervals, plus the possible provision of an admiral’s bridge.²²

The Sketch Design was completed by the end of 1970 and then refined over 18 months, after which an invitation to tender was placed with industry. The design team was lead by A A Austin and some 5 million man-hours were spent on design work alone. The final result – now described as a command cruiser (CCH) – was no longer based on any earlier design of completed warships, having departed from the aircraft carrier Centaur and the command cruiser Tiger which were both an influence on the early studies. Comparisons with Centaur show just how the relationship between volume and displacement had changed. Internal volume of Centaur was 92,000ft² with a full load displacement of 28,500 tons. By comparison the new CCH had a volume of 90,000ft² and a full load displacement of 19,500 tons. The complement was halved, from 2000 in Centaur to 1000 in the CCH. Displacement was now a poor guide to size, a process which began with the post-war frigate designs. The reasons were the replacement of guns by guided missiles, sophisticated sensors making demands on space, the demand for improvements in accommodation, the replacement of heavy steam boilers and machinery with lighter gas turbines, upkeep by exchange and structural design refinement which enabled some lighter steelwork to be used. The deployment of helicopters plus the necessary maintenance and stores backup also lead to a demand for space.

All these factors produced a voluminous ship with a small draught (6.4m against Centaurs 8.5m) and a high beam-to-draught ratio to maintain stability. The large exhausts from the gas turbines meant extensive trunking and this plus a substantial communications and radar suite resulted in a long island structure. The trunking also impacted on the hangar deck with the result of some loss of space. The provision of gas turbines for propulsion (Olympus TM3B) reduced the engineering complement by half compared with Centaur. However, more senior and skilled grades were required. Provision was also made to enable a gas turbine to be removed from the ship via the trunking, a massive advantage over steam practices. The ship’s high freeboard and the provision of two pairs of non-retractable stabilisers resulted in a very seaworthy design with little water being shipped over the bow.

Illustrious arriving at Portsmouth on 27 January 1983. Note the Vulcan Phalanx CIWS right aft on the starboard side, an emergency fit for the Falklands deployment, since replaced by the Goalkeeper system in the CVLs.

(D K Brown collection)

Construction was not always straightforward, for there was some buckling problems during building which were overcome by the use of horizontal stiffen-ers. Damage control requirements meant that the communal deck below the hangar deck included the main passageway in the ship, no through passages being permitted below this level. There were no longitudinal bulkheads within the hull. Fresh air filters also had to be worked into the design for use if there was a nuclear, biological or chemical attack. The flight deck was angled slightly to port to clear the Sea Dart launcher. Six helicopter spots and four run-up points for Sea Harriers were incorporated. A further innovation was the aircraft lift. In previous designs this structure involved the use of heavy chains and balance weights, but in this case a new system involving hydraulic rams, probably evolved from that specified for CVA-01, was produced by MacTaggart Scott, achieving a considerable weight-saving. Another innovation was the ‘Ski Jump’ ramp designed by D R Taylor in the early 1970s which result in the disposable load on an aircraft being increased by 30 per cent and the deck run reduced, leaving more space for Sea King operations, a massive increase in effectiveness.²³

The first ship, Invincible, was ordered from the lead yard Vickers, Barrow in 1972 and completed in 1980, being followed by Illustrious and Ark Royal, which were both built by Swan Hunter and delivered in 1982 and 1985. They were described as a ‘new beginning’ when first delivered and ultimately came to be known as aircraft carriers, an immensely politically sensitive term following the cancellation of CVA-01 in 1966. Invincible cost £184.5 million at 1980 prices, the original estimate in the early 1970s being £60 million. They have proved of immense value to the Royal Navy, having operated as commando ships on occasion and, now that they can also operate RAF Harriers, have become effective small attack carriers, a tribute to their flexibility.²⁴

Invincible on 31 October 1980 undertaking first launching of a Sea Harrier using 6½° ski jump.

(D K Brown collection)

¹ ADM 138/818: 1952 Fleet Carrier – New Design (NMM). The merits of the options considered in the Malta design are outlined in D K Brown, Nelson to Vanguard, pp53–6.

² ADM 1/24145: 1952 New Design Aircraft Carrier (PRO). The ‘Skew’ landing deck was soon being described as an ‘Angled’ deck.

³ ADM 1/24508: 1952 New Design Fleet Aircraft Carrier. When the Malta design was approved by the Board of Admiralty in August 1945 the only Admiralty-controlled dock in the British Isles capable of handling the ship – and then only with difficulty – was AFD 11 then located at Portsmouth Dockyard (ADM 167/124, PRO). The building slip at Devonport was extended to 1000ft with the aim of constructing large carriers. Land was also purchased which would have enabled the slip to be extended to 1500ft (information from D K Brown).

⁴ ADM 13/818: 1952 Fleet Carrier – New Design (NMM). The machinery order requirement is recorded in ADM 1/24508 (PRO). A meeting of the Sea Lords in April 1953 which discussed the ‘Shape and Size of the Fleet after 1960’ and concluded that the new Fleet Carrier was too large is recorded in the First Sea Lord’s Records held in ADM 205/102 (PRO). See also ADM 205/163: 1947 – 1960 Size and Shape of the Navy (PRO). The final set of particulars are recorded in a note produced by G Bryant on 15 January 1960, which is held in Ship’s Cover ADM 138/888: CVA-01. There is an excellent discussion of the 1952 Fleet Aircraft Carrier in Norman Friedman, British Carrier Aviation.

⁵ ADM 1/25149:1953–54 Design of cheapest possible Aircraft Carriers to operate modern fighters: proposals (PRO). Details of the 28,000-ton Aircraft Carrier were recorded in a book of studies presented to the Sea Lords on 30 November 1954. The description but not the drawing is held in ADM 138/789: Guided Weapon Ships 1 (NMM). The minutes of the meeting which rejected the 28,000-ton design are held in the First Sea Lord’s Records in ADM 205/106 (PRO).

⁶ ADM 205/97 contains the Amended £1610 Million Plan – New Construction Programme dated May 1954 (PRO). The cost of Medium Carriers is recorded in a memorandum by the Director of Plans dated 15 September 1954 held in ADM 205/102 (PRO). A description of the design is held in ADM 138/789: Guided Weapon Ships 1 (NMM). No drawings of the design have been found and the dimensions are not known. ADM 205/170 includes an extract from a Sea Lords’ meeting dated 8 October 1957. The First Sea Lord’s first visit to Bath is said to be in 1955, but it was actually in 1954. In addition to wanting aircraft carriers designed to accommodate VSTOL aircraft, he also wanted them to have a guided-missile armament. This idea was, it seems, adopted and guided missiles were also incorporated at Mountbatten’s suggestion in the new escort destroyer design which evolved into the ‘County’ class.

⁷ ADM 138/888: SCC Project 35 (CVA-01) (NMM). The three planned 45,000-ton ships are recorded in DEFE 13/186: 1957–1960 New Construction Programme (PRO). A note on the table indicates that they were previously described as ‘Guided Weapon Carriers’. Note how the displacement has escalated.

⁸ ADM 138/888 (NMM); and ADM 167/159: 1961 Admiralty Board Memoranda (PRO). Six studies were presented: ‘Study 27’ (42,000 tons), ‘Study 23D’ and ‘23E’ (48,000 tons), ‘Study 29’ (50,000 tons),‘Study 24’ (55,000 tons) and ‘Study 30’ (68,000 tons). All would have carried the American Tartar missile with the exception of ‘Study 27’, which carried Sea Cat. The main radar outfits in all options were Type 985, a 3D radar which was later abandoned, and Type 978. Sonar types fitted were 182 and 184. The project was designated SCC 35 by the Ship Characteristics Committee. A full list of projects as at September 1962 is held in DEFE 24/90 (PRO).

⁹ ADM 167/160: 1962 Admiralty Board Minutes, and ADM 167/154: 1962 Admiralty Board Memorandum (PRO). According to a Treasury minute the displacement of the design studies ranged between 25,000 tons and 68,000 tons. T225/2788: MOD Navy Department – Replacement and Modernisation of the present generation of Aircraft Carriers (PRO). The five studies presented to the Board were ‘Study 50’ (50,000 tons), ‘Study 52’ (52,000 tons), ‘Study 53’ (53,000 tons), ‘Study 55’ (55,000 tons) and ‘Study 58’ (58,000 tons).

¹⁰ ADM 167/161: 1963 Admiralty Board Memoranda (PRO); and ADM 138/888 (NMM). Many of the early studies did not carry anti-submarine helicopters as this task was to be performed by the new escort cruisers developed from c1959. The extent of the conflict between the Royal Navy and the Royal Air Force over the aircraft carrier project is illustrated by a forthright memorandum dated 16 January 1963 sent by the First Sea Lord, Admiral of the Fleet Sir Casper John to the Chief of the Defence Staff which is held in ADM 205/197 (PRO). Other ideas for coping without large fleet carriers were guided-missile cruisers with long range surface-to-air guided weapons, more escort cruisers and 15,000-ton aircraft carriers. All were quickly dismissed. See ADM 205/201: 1963 The Navy without Carriers (PRO).

¹¹ ADM 138/888 (NMM). The cost of the dock in October 1964 was said to be £5 million. T225/2788: 1964–65 Replacement and Modernisation of the present generation of Aircraft Carriers (PRO).

¹² ADM 138/888 (NMM). Had two aircraft carriers been ordered simultaneously it was estimated that £2 million would have been ‘saved’ (ADM 167/164: 1964 Admiralty Board Minutes, PRO).

¹³ D K Brown, A Century of Naval Construction. The last Legend was drawn up in December 1965 and is held in the Ship’s Cover. It does not indicate a tonnage figure for protection. D K Brown worked on problems associated with the propeller arrangements at Haslar. There were worries about the uneven flow into the central propeller, which could cause longitudinal vibration in the shaft. This could wreck the thrust block, which occurred in Illustrious in 1945, and also lead to an early onset of cavitation noise.

¹⁴ ADM 1/29044: Proposed Name for CVA-01 (PRO). The name of CVA-01 was approved by the Queen in May 1964. The design approval and subsequent cancellation are recorded in the 1966 Minutes of the Board of Admiralty held in ADM 167/166 (PRO). The Legend of CVA-01 (SCC Project 35) is held in the Ship’s Cover ADM 138/888 (NMM).

¹⁵ ADM 1/27685: 1960–61 Case for the Helicopter Carrier/Escort Cruiser (PRO). This series of studies illustrates the impact of requirements such as increased speed and increased complement.

¹⁶ ADM 205/193: 1961–1963 Naval Staff Presentations and Studies on Carriers, Escort Cruisers and Nuclear Submarines (PRO). The initial logic behind developing the escort cruisers was to enable the aircraft carriers to concentrate on the operation of fixed wing aircraft, adding to efficiency. In July 1962 Escort Cruiser EC 01 was to replace Tiger, EC 02 was to replace Blake. Lion was to remain in commission after a long refit in 1967–8. The redesign with the CF299 missile (later Sea Dart) caused delay. EC 01 was now due to complete in 1969, EC 02 in 1970 with EC 03 and EC 04 completing in 1971. A fifth ship was also now wanted. The CF299 version was designated SCC 36A by the Ship Characteristics Committee. The earlier studies were presumably designated SCC 36.

¹⁷ ADM 167/162: 1963 Admiralty Board Minutes, and ADM 167/163: 1964 Admiralty Board Minutes (PRO). There had been no intention to convert the Tiger class cruisers until the escort cruisers had to be postponed.

¹⁸ DEFE 24/234: 1966 Future Fleet Working Party – Papers (PRO). Forward-facing hangar doors were ruled out; when open there was too much wind inside the structure.

¹⁹ DEFE 24/238: 1966 Future Fleet Working Party – Report (PRO). Note that the Commando Cruiser was now styled as a Cruiser Carrier.

²⁰ ADM 167/166: 1966 Admiralty Board Minutes (PRO).

²¹ T 225/2963: 1966–68 Future Shape of the Fleet following the Report of the Future Fleet Working Party 1966. A Treasury official, J A Patterson, considered it highly unlikely that all six ships would be built.

²² DEFE 24/385–388: The Command Cruiser. By July 1969 there were three ships in the programme. The target timetable was for the Admiralty Board to approve the Sketch Design in October 1970 with the lead ship ordered in February 1972, the ship being accepted in November 1976 and then operational in May 1978. The second and third ships were to follow at about yearly intervals. According to a Treasury memorandum dated 21 October 1969 it was concluded that the original concept of a £30 million cruiser providing for six Sea King helicopters did not provide a big enough capability to be worth the money. (T225/3200: 1967–1969 Design and Construction of a new Command Cruiser for the Royal Navy, PRO).

²³ A F Honnor RCNC and D J Andrews RCNC, ‘HMS Invincible: The First of a New Genus of Aircraft Carrying Ships’, The Naval Architect (January 1982). It seems likely that a group of four Exocet SSM launchers was originally specified, space being provided forward in the vicinity of the Sea Dart launcher. The design of the ship always made provision for operation of the Sea Harrier, but it was to be May 1975 before the politicians formally approved incorporation and an order for the aircraft. D R Taylor is reported to have claimed that Ship Department was opposed to the Ski Jump. This was not so. The problem was that the Treasury had forbidden Ship Department from altering the contract as this had proved a loophole for cost escalation in the past. As a consequence it was necessary for Ship Department to ‘play hard to get’ until a separate contract was negotiated.

²⁴ Ark Royal was originally to be named Indomitable. The cost of Invincible is quoted in Jane’s Fighting Ships 1986–87.