The Arethusa-class cruisers were a class of eight oil-fired light cruisers of the Royal Navy all ordered in September 1912, primarily for service in the North Sea. They had three funnels with the middle one somewhat larger in diameter than the others. All served in the First World War. They were found to be very cramped internally. Design and description The earlier scout cruisers were too slow to accomplish their intended duties of working with destroyer flotillas and defending the fleet against attacks by enemy destroyers. The primary emphasis of the Arethusa-class cruisers was a design speed of , to allow them to lead destroyers in combat. In support of this goal, they were the first cruisers to use destroyer-type high-speed steam turbines and oil-fired boilers were chosen to save weight and increase their power to meet the specification. They retained the side protection introduced in the later ships of the previous , but reverted to a mixed main armament that was a feature of the earlier ships of that class. The ships were long overall, with a beam of and a deep draught of . Displacement was at normal and at full load. The Arethusa class were powered by four direct-drive steam turbines, each driving one propeller shaft, which produced a total of and gave a speed of about . The six ships that used Parsons turbines were equipped with cruising turbines on the outer shafts, but the two ships that used Brown-Curtis turbines were not so fitted. The turbines used steam generated by eight Yarrow boilers at a working pressure of . They carried tons of fuel oil that gave the ships with cruising turbines a range of and for those without, both at . The main armament of the Arethusa-class ships was two BL 6-inch (152 mm) Mk XII guns that were mounted on the centreline fore and aft of the superstructure and six QF 4-inch Mk V guns in waist mountings. They were also fitted with a single QF 3-pounder anti-aircraft gun and four torpedo tubes in two twin mounts. Ships , built by Chatham Dockyard, laid down 28 October 1912, launched 25 October 1913, and completed August 1914. She was sunk by mine off Felixstowe on 11 February 1916. , built by Devonport Dockyard, laid down 24 October 1912, launched 30 September 1913, and completed September 1914. She took part in the sinking of the