Emerald-class cruiser

The E class were based on the preceding Danae class, itself based on the C-class cruiser, but had a very high ratio of length to beam and only one more gun, despite being much bigger and more expensive. Much was sacrificed to achieve 33 knots (61 km/h; 38 mph), the horsepower was doubled and the hull increased by 100 ft (30 m) in length, with a 50% increase in displacement. Only two ships were built, and completed in 1926. Four propellers were necessary for the increased power and were driven from two engine rooms. There were four boiler rooms, nos. 2 and 3 being arranged side-by-side with the exhausts trunked into a common funnel. The magazines were between boiler rooms nos. 2 and 3 and the forward engine room, and between boiler room no. 4 and the after engine room. This led to a bizarre funnel arrangement, accentuated further when in 1935 a longer catapult required the mainmast to be stepped forward of the after funnel, and the funnels were heightened by 5 ft (1.5 m).

In the early 1930s Enterprise was fitted with a prototype twin 6-inch (150 mm) turret in place of her two forward single mounts; and with trials of the turret proving successful it was retained on Enterprise for the rest of her career. The turret design was later installed in the Leander, Amphion and Arethusa classes. The turret installation occupied less space than the superimposed 'A' and 'B' guns of Emerald, therefore the bridge was placed further forward. The bridge was of a new design, being a single block topped by a director tower, rather than the traditional platforms built around the foremast and wheelhouse topped with a spotting top. This design of bridge would appear in the County-class cruisers.

Notwithstanding their age and outlandish appearance these two ships were still the fastest cruisers in the Royal Navy at the outbreak of World War II, Emerald exceeding 32 knots (59 km/h; 37 mph) in a full-power trial at full load in 1939. Both cruisers also carried the heaviest torpedo armament of any Royal Navy cruiser – four quadruple mounts. These cruisers had a long range, unlike the C and Danae-class cruisers, making them valuable for patrolling the sea lanes against Axis merchant raiders. They were also large enough that they could accommodate significant additions to their anti-aircraft armament as well as modern radar suites.

Hawker Osprey K5749 on Enterprise's catapult in May 1936

In the mid-1930s both ships were fitted with a catapult which replaced the out-moded flying-off platform and had HACS Mk.I added for the 4-inch (100 mm) guns, which was fitted amidships between the searchlight platform and the after funnel. The funnels were raised 5 ft (1.5 m) at this time. Later proposals to increase the AA outfit by the addition of twin 4-inch and multiple 2-pounder guns were thwarted by the outbreak of war. Emerald had received two quadruple .5 machine guns before the war, then during refit between August 1942 and April 1943 she landed the after 6 in, two 2 pdr singles and the .5 machine guns to receive instead six power-operated twin 20 mm and two quadruple 2 pdr guns and radars Type 273 (centimetric target indication), 281 (air warning), 282 (pom-pom ranging) and 285 (HACS ranging). In April 1944 six 20 mm single mounts were added and the catapult was removed.

Enterprise landed two 6 in singles in 1941 and had one quadruple 2 pdr fitted. She later had four single 20 mm fitted and then, in the course of a long refit between the end of December 1942 and October 1943, she lost the single 2 pdr and 20 mm weapons, receiving six twin power-operated mountings in lieu. The two 6 in were reinstated and a second quadruple 2 pdr fitted. She was fitted with radars Type 272 (centimetric target indication), 281, 282, 284 (6 inch gun ranging), and 285. In February she had an additional four single 20 mm fitted and the catapult was removed.

Like the Cavendish class, they were mainly employed on the ocean trade routes, also seeing fleet service in the Far East in 1942–43 with the East Indies Fleet. However, unlike almost all of the other older cruisers, both ships had active employment until the last few months of the war, in almost every theatre. Enterprise served in Force H in 1940 when that naval task force attacked the French naval squadron at Mers-el-Kebir in July 1940. Enterprise after her 1942–43 refit served with the Home Fleet where, in company with the cruiser Glasgow, she participated in the successful battle against a well-armed German destroyer and torpedo boat force in December 1943 in the Bay of Biscay.

Emerald supported British forces in their campaign putting down the pro-German revolt in Iraq in the summer of 1941. Both cruisers provided gunfire support off the Normandy Invasion beaches in June 1944. Both cruisers were reduced to reserve by January 1945 though Enterprise was reactivated for use in trooping duties upon the ending of World War II.

• British and Empire Warships of the Second World War, H T Lenton, Greenhill Books, ISBN 1-85367-277-7
• Conway's All the World's Fighting Ships, 1922–1946, Ed. Robert Gardiner, Naval Institute Press, ISBN 0-87021-913-8
• Brown, David K. (1997). "Re: E's and Super Es". Warship International. XXXIV (1): 7–8. ISSN 0043-0374.
• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
• McBride, K. D. (1996). "Es and Super-Es". Warship International. XXXIII (3): 257–278. ISSN 0043-0374.
• Raven, Alan; Roberts, John (1980). British Cruisers of World War Two. Annapolis, MD: Naval Institute Press. ISBN 0-87021-922-7.
• Rohwer, Jürgen (2005). Chronology of the War at Sea 1939–1945: The Naval History of World War Two (Third Revised ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2.
• Whitley, M. J. (1995). Cruisers of World War Two: An International Encyclopedia. London: Cassell. ISBN 1-86019-874-0.
• Woodbridge, W. D. (1997). "Re: E's and Super Es". Warship International. XXXIV (1): 8. ISSN 0043-0374.

Wikimedia Commons has media related to Emerald class cruiser.

• Emerald class at U-boat.net