Tiger-class cruiser

By 1944, the Minotaur class were widely viewed as obsolete. The added weight caused by the necessary addition of anti-aircraft guns, radar, electronics and the crew required to operate these, meant that they would exceed structural strength and deep-water stability limits. The design also lacked the speed and size of required for service in the Pacific or Arctic.

HMS Minotaur itself and the Crown Colony-class Uganda were gifted to Canada in April 1944. The Royal Navy's last wartime-built cruiser, Minotaur, was handed over on schedule to the RCN in June 1945. It was the first British cruiser with both Type 275/274 "lock and follow", air- and surface- fire control and quadruple 40mm Bofors guns.

A proposal to sell two updated Tiger-class cruisers to the Royal Australian Navy (RAN) was approved by Winston Churchill in 1944.[2] On 4 April 1944, Australia's war cabinet approved construction or acquisition of a cruiser and destroyer, for £6.5 million, to replace HMAS Sydney and HMAS Hobart. Despite the opposition of Australian shipbuilders and the Royal Australian Air Force, the Australian prime minister John Curtin agreed (on 18–21 May 1944, while visiting the UK) to the transfer of new RN ships, provided sufficient RAN crews were available to man them.[3] Had the ships entered Australian service, they would have operated as part of British Pacific Fleet carrier groups. The RAN ships would have been re-armed with twin 5.25-inch (133 mm) gun turrets[4] or triple 5.25-inch turrets (a 1942 design option for RAN cruisers).[5][6] [7] While the RAN strongly supported the purchase, elements of the Australian government perceived that they were being sold ships unwanted by the RN and preferred to support and expand local shipbuilding capacity. In addition, the Allied Supreme Commander, South West Pacific Area, US General Douglas MacArthur, recommended that Australia should prioritise air defence of its existing bases and continue to rely on the wartime protection provided by the US Navy, rather than expanding the RAN fleet. Nevertheless, in February 1945, the Australian government's Defence Committee reaffirmed acceptance of two Tiger-class cruisers.

Unlike the Canadian transfer, the UK Treasury was not going to gift the cruisers to Australia. By mid-1945, the UK was facing severe constraints caused by Lend-Lease payments. Among other effects, this led in September 1945 to the cancellation of a batch of 25, US-built, Mk 37 Type 275 radar-assisted gunnery systems, and this affected ships including the Tiger class. Nevertheless, the UK still wanted payment for the two Tiger vessels, or an equivalent writing-off of repairs on RN ships in Australian dockyards. On 11 April 1945, the UK priced the two ships at £9 million.[8] In June 1945 the Australian government cancelled the transfer of payments for Defence and Blake, on the grounds that neither ship was ready and that it had insufficient crews for the cruisers because it was also acquiring British aircraft carriers and destroyers. The RAN was then offered the temporary transfer of a Town and a Crown Colony-class cruiser, until the Tiger-class were ready. This proposal was also rejected on the basis of redundancy, as the two County-class heavy cruisers already in Australian service,[lower-alpha 2] were deemed to have at least five years service life remaining.[9][10] The Tiger-class was thus never adopted by the RAN.

In 1944–45, the RN had hoped that the new large Battle-class and Daring-class destroyers would be developed as substitutes for cruisers in many roles, but the First Sea Lord, Andrew Cunningham, realised that the UK budget could not support increasing the destroyer's size from 2,800 to 3,500 tons required for a three-turret ship with adequate anti-aircraft and anti-surface fire control. With the Neptune class scrapped, the suspended ships were the only cruiser hull option and worth considering for rearmament. By 1946, nine Mk24dc turrets were 75–80% complete with three further turrets partially complete for use with either the Tiger or Neptune-class cruisers. These turrets were a more advanced version of the wartime Mk 23 triple 6-inch (150 mm). The new Mk 24 6-inch mounts were interim electric turrets with remote power-control and power-worked breech. The heavier Mk 24 offered a dual purpose gun with 60-degree elevation.[lower-alpha 3]

The Tiger design had a broader 64 ft (20 m) beam than Superb on which to accommodate the larger turrets. But it was preferred to complete Superb with the older Mk 23 turrets in 1945, a 64 ft beam Swiftsure. The 1942 Tiger design was redesigned with better protection and internal division to take advantage of a three turret design with four 40 mm "Stabilized tachymetric anti-aircraft gun" mounts (STAAG) for close defence with Type 262 radar, Action Information centre, more pumps and generators.

By March 1944 Defence and Blake were all but signed off for transfer to the RAN to be completed as 5.25-inch gun cruisers.[11] British production of 5.25 turrets was slow and little work was done on the cruisers other than to launch Defence in September 1944.[11][12][13][14] The fact that they were years from commissioning guaranteed that Australia rejected the deal.

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. It appears that the 1942 programme Hawke and Bellerophon were destroyed in 1944 and reordered as improved Town-class light cruiser and Neptune-class cruisers in February 1944 and February 1945. Janes Fighting Ships 1944–45, states that Hawke was laid down in August 1944[15] as a Tiger. The naval authorities of the time and through the Cold War hold that the Neptune class were under construction, the main and secondary twin 4.5-inch (110 mm) turrets, boilers and machinery for the first three ships ordered and being built in advance of the hull construction, as it was planned to get the first two Lion-class battleships underway.[16] At the end of the war it was thought Bellphoron's hull was already under construction at Newcastle, but Hawke, an Improved Belfast with a 76 m (249 ft) beam or the first Neptune was almost ready to launch in Portsmouth dockyard[17] The more advanced of the two ships, Hawke, was broken up in 1947, a controversial decision as although she was still on the slip in the Portsmouth dockyard her boilers and machinery were complete and her new 6-inch guns close to completion.[18]

The whole class, which was constructed with a tight, cramped, and near impossible to modernise citadel, was nearly superseded by the completely redesigned N2 8500-ton 1944 cruiser, within the same 555 ft × 64 ft (169 m × 20 m) box of the Colony/Minotaur design, which was approved by the Admiralty Board on 16 July 1943.[19][20] The design had four twin automatic 5.25-inch guns, better range, internal space, subdivision and economical 48,000 hp (36,000 kW) machinery for 28 knots (52 km/h; 32 mph). Twenty four of twenty-five leading RN admirals and the Sea Lords favoured the N2 and preferred the lighter dual purpose 5.25 turrets; the incoming new First Sea Lord Cunningham disagreed believing 6-inch guns were essential. By 1944 the 5.25 RP10 was an improved gun and mount, compared with the 1942 version [lower-alpha 4] and development of two prototype automatic 5.25-inch twin turrets continued at Vickers until 1948.[23]

In 1948 the Royal Navy had proposed in "Ships of The Future Navy" to replace 23 cruisers and 58 fleet destroyers with 50 light cruisers with Cruiser/Destroyers - four 5-inch guns, torpedoes, anti-submarine mortar and "good radar" on 4–5,000 tons displacement built to destroyer standards.[24][25] The Admiralty offered the government two such proposals in 1951: a new broad beam Bellona class with four twin Mk 6 4.5-inch guns and an enlarged version of US Mitscher and Forrest Sherman-class destroyers with British machinery and sensors with three single US 5-inch/54 and two twin US 3-inch/50-caliber guns.

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 (as was any further cruiser reconstructions) to 1954. The original decision to delay the Tigers in the late 1940s was to reassess cruiser design and the provision of effective anti-aircraft (AA) fire-control to engage jet aircraft which was beyond UK industrial capability at the time.[26] Consequently, higher priority was given to the battleship HMS Vanguard, the Battle-class destroyers and the two new Audacious-class aircraft carriers (Eagle and Ark Royal) for allocation of the 26 US-supplied medium-range anti-aircraft gun directors (delivered through Lend-Lease in 1944/5)[27] The US supplied version of Type 275 High Altitude/Low Altitude DCT were stabilised and tracked multiple air targets of Mach 1.5+, the US directors were superior to the fragile UK version of Type 275, the only medium-range AA fire control until 1955, which could barely distinguish transonic targets at Mach 0.8.[28] The 1947–49 period saw a peace dividend, and frigate construction became the priority in the Korean War.[29]

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 (Mark 26 automatic mountings) 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 auto 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 for naval gunfire support (NGS) was not a design requirement. The automatic twin 6-inch guns for the secondary role of defence and attack on trade also provided some very high level (up to 8-mile altitude) anti-aircraft capability. In historical terms, it represented a light armament and similar US weapons introduced on USS Worcester had experienced considerable problems with jamming and had performed below expectation.[30] A third lower-cost option of fitting two Mk 24 turrets in 'A' and 'B' positions and two to four semi-automatic Mk 6 twin 4.5-inch[lower-alpha 5] 'X' and 'Y' turrets and on the flanks was considered during the Korean War [31] as an immediate surface fighting response to Sverdlov. However the 1945 Neptune-class Mk 24 6-inch turrets and Mk 6 4.5-inch mounts required a crew of 900+[32] But like the Colony-class in the 1950s, only one 6-inch turret would have been manned. However, as with the proposed 1951 Bellona Mk 2, the RN 4.5-inch DP was not a good postwar AA weapon.[32] The six Mk 24 DC turrets were unfinished and complex, with two pairs of Type 274 and Type 275 directors. The first UK-sourced reliable 275M directors were fitted in 1956, in Royalist and in Type 12 frigates, 14 years after the introduction of the US Mk 37 DCT.[33] This confirms in late 1951 UK industry could still not build precision bearings or work to the fine tolerances needed for accurate naval AA fire and fire-control box components had to be ordered from the US. By 1953, US Mk 63 directors in the MRS 8 directors for close-in defence had been fitted at US expense in most major RN units and cruisers. Newfoundland was reconstructed to a pattern very similar to that planned for HMS Hawke and the Tigers with 2/274 surface DCTs with the unreliable, UK glasshouse 275 offset. On exercise AA firing Royalist easily outshot Newcastle.[34] DC wiring had been removed from the Tiger class in 1948 and the dated Mk 24 was not suitable for fast completion of the class [35] There was a strong desire that the new cruisers should have AC power, not DC or dual.[36]

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 Sverdlov class 6.9-inch armour and speed and range also outclassed the two turret 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 including Charles Lillicrap, the Director of Naval Construction in 1946 who saw the new 3-inch/70 as eliminating the need for the new Mk 26 directors and advocating suspending cruiser design as much as lack of finance. [37] 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 and proposed new 5-inch guns. The proven Mk 23 seemed more than adequate and its efficiency was improved in the 1950s.[lower-alpha 6]

In 1954 construction of the three ships was approved to the 1948 design mounting new automatic 6-inch and 3-inch guns. This was a controversial decision, made to avoid ordering larger cruisers or new aircraft carriers of questionable utility at immense cost and the apparent Soviet Sverdlov threat. The Tigers lacked the deep water speed and armament to challenge the Russian ships, on paper, while other RN officers thought a couple of Darings or Type 41 frigate anti-aircraft frigates were all that was needed to challenge the inexperienced Russian crews.[38] Cruisers were better deterred and sunk by aircraft carriers operating Hawker Sea Hawk and de Havilland Sea Venom strike aircraft.[39][lower-alpha 7]

The November 1954 cabinet meeting deciding the fate of the Royal Navy took six hours. Churchill was determined to limit the defence budget with a view to developing nuclear weapons and less vulnerable RAF aircraft.[41] The cheaper Tigers were approved in 1954, the Royal Navy estimating completion in three years for £6 million compared with five years and £12m for a new cruiser design.[42] The new automatic twin 6-inch and twin 3-inch dual-purpose guns designed for larger cruisers like the Minotaur were approved for production. The modernised Tigers were an interim measure with the expectation that guided missile equipped ships were "at least ten years away". The 1957 Defence White Paper under Duncan Sandys proposed to reduce the active cruiser fleet[43] the Tigers, Swiftsure and Superb [lower-alpha 8] would enter service as interim anti-aircraft ships, until the County-class destroyers were commissioned and the two Second World War cruisers, HMS Belfast and HMS Bermuda were mothballed.

While outwardly identical, the three Tigers where each very different in their electrics. Blake was essentially an experimental cruiser with all-electric turrets able to engage Mach 2.5 air targets but was put in reserve in 1963 for lack of technical staff.[44][45] Lion had deteriorated after eight years in Gareloch before reconstruction as a Tiger and had to be withdrawn from operations "East of Suez" in 1963 due to boiler, mechanical and armament problems.[46] HMNZS Royalist, with some Royal Navy crew, was reactivated as a surface escort for carrier groups in Southeast Asia in 1964 to deter the threat of the Indonesian Sverdlov and in 1965 to support the amphibious carriers with air defence and general fleet support. By 1966 Royalist, like Blake and Lion, was unsustainable in the year of the confrontation with Indonesia. The large Darings were refitted (from 1961) with MRS3 fire-control to provide a substitute for the Tigers; their three turrets giving them an advantage over the Tiger.