Tiger-class cruiser


The Tiger class were a class of three British warships of the 20th century and the last all-gun cruisers of the Royal Navy. Construction of three cruisers began during World War II but, due to post-war austerity, the Korean War and focus on the Royal Air Force over the surface fleet, the hulls remained unfinished. Against a background of changing priorities and financial constraints, approval to complete them to a modified design was given in November 1954 and the three ships –, and – entered service from March 1959.
In January 1964, due to postponement of the Escort Cruiser programme, the cruisers were approved for conversion into helicopter-carrying cruisers. At first they were intended to carry four Westland Wessex helicopters for amphibious operations and anti-submarine protection operating "East of Suez" then four Westland Sea Kings for anti-submarine work. The conversion of Blake and Tiger, carried out between 1965 and 1972, was more expensive and time-consuming than expected and, with the UK Treasury opposing each cruiser's conversion, the conversion of Lion was cancelled and she was scrapped in 1975, having been used for spares for her sister ships.
Described in one book as "hideous and useless hybrids" after conversion and with limited manpower, resources, and better ships available, Tiger and Blake were decommissioned in the late 1970s and placed in reserve. Blake was scrapped in 1982 and Tiger in 1986.

Design and commissioning

The three light cruisers that become the Tiger class came out of an order for eight 64-foot broad beam Modified and Improved Fiji-class cruisers as an immediate response to the Japanese attack on Pearl Harbor and the invasions of Siam and of British Malaya in December 1941. The order was part of the Royal Navy 1941 supplementary shipbuilding programme and 1942 estimates in April 1942 They were slightly improved models of the Ceylon sub-group of the Fiji-class ordered in late 1939 and the 63-foot beam Minotaur group ordered in the 1941 Royal Navy programme. HMS Defence, Bellerophon, Blake and Hawke were begun as Minotaur-class cruisers in 1941–43 with three triple 6-inch gun turrets in 1944. Production of the 1942 Design Light Fleet Carriers was given priority from August 1942 by the Future Building Committee and in August 1942, four unnamed Minotaur cruisers were cancelled and their machinery, builders and building slips reallocated to light fleet carriers. Bellerophon had been ordered in May 1941 and the keel laid down at with Swiftsure and Minotaur in October 1941. Blakes keel was started at Fairfields in August 1942. While the building schedules of Minotaur, Swiftsure and Defence were unaffected; construction of Blake and Tiger slowed; Hawke was not laid down until July 1943 and the eighth was never started. The priority of the light fleet carriers, anti-submarine escorts, the battleship Vanguard at Browns, and the large fleet carrier HMS Africa, ordered from Fairfield effectively suspended work on Bellerophon and Blake from March 1944 to July 1945. Work on Defence was delayed by industrial relations, strikes, conditions, sub-standard facilities and low quality steel at Scotts, Greenock. The problems at Scotts and concern over the delay to Defence and the Tiger-class led the Director of Naval Construction to visit Scotts' yard in August 1943 with work stopped by striking riveters, carpenters and shipwrights It was planned to launch Defence in April 1944 to complete in July 1945, for Hawke to launch in 1944 and commission mid-1945, with Blake and Tiger commissioning mid-1946. However only Minotaur, Swiftsure and were completed by late 1945. Defence, well advanced in construction, was placed in reserve without armament fitted and spent eight years moored offshore in Gareloch.

Design changes

In March 1943 it was decided to upgrade the main armament from the Mk XXIII triple 6-inch turret to the dual purpose electrically-powered Mk XXIV triple 6-inch on five cruisers ordered or under construction: Blake, Hawke, Tiger, Defence and Bellerophon. The guns in the new Mk 24 turret could reach a maximum of 60 degrees of elevation giving some anti-aircraft capability. The three more complete Minotaur cruisers, HMS Minotaur, Swiftsure and Superb would complete with the Mk 23 turret. In January 1943 it was decided to increase the beam of Bellerophon to.
By late 1943 the effective defeat of German surface forces and the large American cruiser construction programme made the cruiser requirement less urgent. The planned delivery of fleet carriers, the light fleet carriers, escort carriers and the new Battle-class destroyers in 1944-45 made limiting the manpower requirements and future building programme an absolute priority for Churchill by October–December 1943 The RN had more cruisers and refitted cruisers than it had crew for and as a result two new classes of 5.25-inch gun cruisers - five 7,000 ton with three twin 5.25-inch turrets and the N2 class - were cancelled by February 1944. Tiger-class construction was slowed and periodically suspended and new class of large Neptune-class cruisers were delayed. Two new cruisers were passed to the RCN as Canada was seen as the UK's vital wartime ally; HMS Minotaur and the cruiser were gifted to Canada in April 1944 and Minotaur was handed over on schedule to the RCN in June 1945.
A proposal was made in 1944 and again in February 1945 for two new cruisers and two light aircraft carriers to be delivered to the Royal Australian Navy; the UK offering HMS Defence and Blake. The offer was delayed because Australia also had a manpower problem; by mid-1945 the manpower issue had not resolved and the Allies had overwhelming naval superiority and the idea was dropped. The RAN determined the service life of its two County-class heavy cruisers could be extended to 1950-54.
In 1944–45, the RN, CNS and government thought the merging of the cruiser and destroyer categories was too early, expensive and radical. With the planned cancelled, the suspended ships were the only cruiser hulls available and worth considering for rearmament. By 1946, nine Mk 24 turrets were 75–80% complete with three further turrets partially complete for use with the Tiger cruisers. These turrets were a more advanced version of the wartime Mk 23 triple. The new Mk 24 6-inch mounts were interim electric turrets with remote power-control and power-worked breech. The Tiger design, like Superb, had a broader beam - a foot wider at beam - than Swiftsure on which to accommodate the larger turrets though it was preferred to complete Superb with the older Mk 23 turrets in 1945.
It was decided to mothball the three incomplete Tigers in November 1947 as the aircraft carriers Eagle and Centaur had priority. The Tigers were maintained as in some ways they were newer hulls with better internal and underwater protection, subdivision and compartments taking advantage of the removal of the hangar and X turret, Action Information centre, more light AA, pumps and electric generating capacity.
Another two Tiger-class cruisers were cancelled. Hawke was laid down in July 1943, and Bellerophon possibly had a keel laid down. Work on all the cruisers other than Superb stopped after mid-1944..Hawke was suspended in January 1945, and broken up in 1947 in the Portsmouth dockyard although her boilers and machinery were complete, and her new 6-inch guns close to completion.

Delay and redesign

The second Churchill government, elected in 1951, favoured the RAF and reduced the naval budget. With the RN priority being anti-submarine frigates, the restart of work on the Tiger cruisers was delayed by three years to 1954. The original decision to delay the Tigers in the late 1940s had been to reassess cruiser design and the provision of effective anti-aircraft fire-control to engage jet aircraft which was beyond UK industrial capability at the time. Consequently, higher priority was given to the battleship, the Battle-class destroyers and the two new aircraft carriers for allocation of 26 US-supplied medium-range anti-aircraft gun directors The US version of the Type 275 High Altitude/Low Altitude DCT were stabilised and could track multiple air targets of Mach 1.5+. These US directors were superior to the British built Type 275 which was the only medium-range AA fire control until 1955 and could barely distinguish transonic targets at Mach 0.8. The 1947–49 period saw a peace dividend, and frigate construction became the priority in the Korean War.
By 1949 two alternative fits for the Tigers had been drawn up, one as anti-aircraft cruisers with six twin 3-inch 70 calibre and one with two twin QF 6-inch Mark N5 guns and three twin 3-inch/70s. Both were designed primarily for high-level anti-aircraft defence and largely intended as a replacement for the 5.25-inch and 4.5-inch turrets on battleships and old fleet carriers. The rapid-fire automatic twin 3-inch and 6-inch were designed on a post-war philosophy that the first 20 seconds of anti-jet aircraft and anti-missile engagement were critical and that the twin 3-inch firing at 240 rounds per minute would successfully engage six air targets in 20-second bursts. Sustained fire capability for naval gunfire support of ground forces was not a design requirement. The automatic twin 6-inch guns for the secondary role of defence of and attack on trade also had some very high level anti-aircraft capability. In historical terms it represented a light armament and similar US weapons introduced on had experienced considerable problems with jamming and had performed below expectation. A third lower-cost option of fitting two Mk XXIV turrets in 'A' and 'B' positions, two semi-automatic Mk 6 twin 4.5-inch in 'X' and 'Y' positions and a twin or single 4.5-inch on each flank was considered at the start of the Korean War. This could not have been completed before 1953 as an immediate surface fighting response to a Soviet Sverdlov-class cruiser and would have required a crew of 900+. Further the RN 4.5-inch DP gun was not a good postwar AA weapon., the six Mk 24 DC-powered turrets were unfinished and complex DC wiring had been removed from the Tiger class in 1948 and so the Mk 24 was not suitable for fast completion of the class. There was a strong desire that the new cruisers should have AC power, not DC or dual systems.
There was great doubt of the merits of completing the Tigers, given that Soviet Tupolev Tu-95 "Bear" turboprop and Tupolev Tu-16 "Badger" jet bombers flew faster and higher than anticipated which added to the argument for missile equipped-ships for anti-aircraft defence. The with 6.9-inch thick armour, speed and range also outclassed the Tigers. Even six-inch bombardment was increasingly unacceptable to the Royal Navy after Korea and was allowed only on the first day of Operation Musketeer after strong political opposition. The RN staff were completely divided over the development of new AA guns larger than 4-inch post war. Charles Lillicrap, the Director of Naval Construction in 1946, saw the new automatic 3-inch/70 as eliminating the need for the new Mk 26 DP 6-inch guns, as the guns fulfilled the AA requirement. That and the fact the new twin 3-inch/70 and twin Mk 26 6-inch were six years from being tested led to both Tigers and Minotaurs being suspended in 1947 and slowed work on the new 6-inch guns. The proven Mk 23 seemed more than adequate and its efficiency was improved in the 1950s.