Minotaur-class cruiser (1947)

The Minotaur class, or Design Z, was a proposed class of light cruisers planned for the British Royal Navy shortly after the Second World War. Design Z had several proposed configurations with differing armament and propulsion arrangements. The designs were large ships that were planned to be armed with ten 6 in quick-firing dual purpose guns and an extensive array of 3 in secondary guns. Six ships of the class were planned in 1947 but they were ultimately cancelled before construction could begin, owing to the economic difficulties of the United Kingdom and shifting naval priorities.

Development and design
The Design Z proposals for light cruisers were evolutions of the Design Y proposals, also known as the, that were planned during the final years of the Second World War. Design Z was borne from increased crew size and habitability standards which demanded a larger ship than Neptune. The Director Gunnery and Anti-Air Division (DGD) further proposed to have future cruisers armed with dual-purpose 6 in and 3 in guns as on the American. In 1946, following orders from Deputy First Sea Lord to redesign existing cruiser design for improved habitability, the Director Naval Construction (DNC) developed a series of designs that would mount the new twin 6 in Mk 26 mounts; these designs were designated as different versions of Design Z.

In a June 1946 meeting that compared the Neptune design with the various Design Z versions, the First Sea Lord deemed the version D with five twin 6 in Mk 26 mounts and eight twin 3 in to be acceptable; the design had three superfiring Mk 26 mounts forward and two aft. This design was then given the name Minotaur to distinguish it from the Neptune designs and replaced the latter in the building programme. The Minotaur design would displace 15280 LT standard and 18415 LT deep load.

In 1947, the DNC compared the Minotaur design with Worcester; the comparison file also included several Design Z alternatives and refinements to Minotaur. Design Z4C combined engine and boiler rooms, while designs ZA and ZB were two smaller alternatives with the same general combat characteristics such as armament, protection, and speed, but with reduced space. Design ZA also had the front two turrets mounted at the same level and reduced the overall length, which then required an increase in propulsive power from 100000 shp to 110000 shp to make the required 31.5 kn.

The cruiser programme, which consisted of the new Minotaur class and completion of the Tigers, was suspended in 1947 due to lack of immediate threat, the austerity budget imposed by the Labour government and to allow reconsideration of cruiser design. It was thought that a RN 'cruiser/destroyer', similar to and derived from the US Mitscher-class Destroyer Leaders of about 3750 tons (a concept which, in 1949-51, the RN envisaged as potentially armed with three US Mk 54 single 5-inch and two twin 3-inch 50-cals) might be sufficient to meet the limited interim threat perceived from Soviet gun cruisers. Design work, however, continued on the Minotaur class in the meantime.

The Korean War, along with the arrival of the 20,000 ton Soviet Sverdlov design, saw the Naval staff once again put cruiser options before the UK Cabinet in 1951. The options were; (1) A fully designed Minotaur (1951) cruiser with 5 twin Mk 26 6 inch turrets but (halved) 4 twin 3-inch/70 AA armament ; (2) Mk 3 broad beam Dido cruiser with 4 twin Mk 6 4.5 turrets and; (3) Immediate restarted Tiger class with Mk 24 turrets in A & B and Mk 6 4.5 twins in X and Y positions - probably similar to the final offer to complete the class for the RAN in mid 1945. The decision was, however, to complete the Tiger to a 1948-9 design, with Mk 26 twin 6-inch and 3-inch/70 armament.

The options for a new cruiser alternative to the Tiger in November 1954 were; the C17, small cruiser of 10,000 ton light with 3 twin Mk 26 6 inch and four Mk 11 L/70 or; a new Tiger sized cruiser with a 'cruiser/destroyer' armament of two twin 5/56 (in large turrets sized for the cruiser) and two twin L70, with cruiser armour and AD/AW processing. The evident difficulty of developing rapid fire 5 inch guns of acceptable weight & reliability meant, however, that in 1955 it was decided to limit gun options for missile cruisers to the new twin 6 inch a 3/70. This resulted in the several missile cruiser designs that received staff approval in 1956/7 being similar in dimensions to the proposals of 1947 & 1951 for the Minotaur, with two twin Mk 26 6 inch in A and B position, 2-4 twin 3/70 turrets and L/70 light AA.

A Minotaur size hull and armour was seen by naval staff as necessary for major Pacific and Indian Ocean carrier escorts with long range endurance, stores & workshops, as well as modern guns & missiles combining surface and AA guns, 3D 984 radar and a viable large Seaslug armoured magazine for 48 Seaslug missiles with 16 of these as nuclear missiles (RAF Bloodhound & USN Terrier AA missiles had special variants). However, First Lord Earl Mountbatten, following the Suez 'debacle' in 1956, saw 'no use' for Cruisers and closed the RN cruiser design department in April 1957 Mountbatten had always favoured smaller guided missile destroyers to carry Seaslug and vetoed nuclear weapons as impractical for anti-aircraft duties, on political and escalation grounds. The cruiser department became the new nuclear submarine design unit.

Armament
The main gun armament was to be ten 6 in quick-fire (QF) Mark V dual-purpose guns in Mk 26 dual mounts. The new Mk 26 mounts had full remote power control (RPC) and featured automatic loading that gave each gun a designed rate of fire of 15-20 rounds per minute, considerably faster than the 6-8 rounds per minute of the older Mk 24 mounts. The guns were individually sleeved and fired a 129.75 lb shell out to 25000 yard. While the Minotaur-class cruisers were canceled, the guns and mountings were eventually fitted onto the, whose hulls were laid down during the Second World War and was later redesigned to accommodate these mounts.

The secondary armament consisted of rapid fire 3 in guns in eight twin mountings that would replace the 4.5 in secondary guns as well as the 40 mm and 20 mm anti-aircraft guns of previous cruiser designs. The DNC considered the 3 in shell to be the smallest that could accommodate a proximity fuse, which made it more ideal for high angle anti-aircraft fire. The Director Naval Ordnance (DNO) also adopted this caliber in order to achieve commonality with the United States Navy which was also developing a twin 3"/70 mount at the time.

Construction programme
A total of six Minotaur-class cruisers were planned over a ten-year period by the Royal Navy, with the same planned names as the preceding Neptune-class cruiser design: Minotaur, Neptune, Centurion, Edgar, Mars, and Bellerophon. The plan involved laying down two cruisers in 1951, 1952, and 1953 with completion in 1954, 1955, and 1956 respectively. Due to cost and the emphasis on aircraft carriers and anti-submarine warfare after the Second World War, this plan ultimately never materialized.