Town-class cruiser (1936)
The Town class consisted of 10 light cruisers built for the Royal Navy during the 1930s. The Towns were designed within the constraints of the London Naval Treaty of 1930. The ships were built in the sub-classes, Southampton, Gloucester and Edinburgh, each sub-class adding more weaponry.
Armament
Like their US and Japanese counterparts, the Town-class cruisers were "light cruisers" in the strict terms of the London Treaty, which defined a "light cruiser" as one having a main armament no greater than calibre. All three naval powers sought to circumvent the limitations on heavy cruiser numbers by building light cruisers that were equal in size and effective power to heavy cruisers. These ships made up for their smaller calibre guns by carrying more of them.All ships of the class carried BL 6-inch Mk XXIII guns in triple turrets, with the centre gun mounted behind the two outer guns to prevent interference between the shells in flight and to give the gunners more room to work in. The turret roofs had cutouts at the front to allow extreme elevation, originally intended to give the guns an anti-aircraft capability. In practice the guns could not be trained or manually loaded quickly enough for continuous anti-aircraft fire, so the Royal Navy designed the Auto Barrage Unit which allowed the guns to be loaded with time-fuzed shells and then fired when the target aircraft reached a set range. These ships were equipped with the HACS AA fire control system for the secondary armament and the Admiralty Fire Control Table for surface fire control of the main armament.
The secondary armament consisted of four twin Mk XIX 4-inch turrets, and two 2-pounder quad pom-poms. Additional light anti-aircraft weapons were added during the war and the 4-inch mounts were converted to Remote Power Control. Postwar and were partially reconstructed in 1949–1951 with enclosed bridges, new lattice masts, improved surface fire control, long range radar and an improved but still unreliable version of the Glasshouse Directors with Type 275 'lock and follow' radar, with flyplane control for the twin 4-inch guns with elevation speed increased to 15–20 degrees per second to engage faster jet aircraft. Similar electronic alterations were made to but it received less structural alteration. was put into reserve in 1952 to preserve it for potential modernisation and had a less extensive refit to allow her to be sent quickly if needed in the Suez crisis of 1956. Birmingham, Newcastle and Sheffield had the pom-pom and 20 mm armament replaced by 40 mm Bofors mounts. Belfast was fitted with MRS 8 HACDT to combine 40 mm and twin 4-inch AA fire and to permit the use of 40 mm proximity fuze ammunition as used by the British Army.
Sub-classes
''Southampton''
In the mid-1930s, the was the Royal Navy's latest light cruiser design, with six vessels to be built. Following the new, heavily armed small cruisers of the United States and Japanese es, the last two planned ships, and, were cancelled and re-ordered as a new, much larger cruiser type, with the new ships named Newcastle and. Based on the initial design chosen in November 1933, the estimated cost of the new ships was £2.1m each compared to an estimated cost of £1.6m each for a cruiser.Initially the class was designated the "M" or "Minotaur" class but was renamed the Town class in November 1934. Uniquely, the final Southampton class cruiser, Birmingham, was built with a fully flared bow and is easily distinguished by the lack of the prominent knuckle found on her sister-ships. This was due to some elements in the Admiralty doubting the benefits offered by the knuckle design. This modification was introduced during construction in March 1935 but was not continued in the follow-on Gloucester class.