|Name||No||Yard No||Builder||Laid down||Launched||Comp||Fate|
|Aurora (RCN 11.1920)||C1, 08||Devonport DYd||24.10.1912||30.9.1913||9.1914||sold for BU 8.1927|
|Arethusa||3C||Chatham DYd||28.10.1912||25.10.1913||8.1914||sunk 11.2.1916|
|Undaunted||2C, A5, 80||495||Fairfield, Govan||21.12.1912||28.4.1914||8/1914||sold for BU 4.1923|
|Galatea||0, 66, 33||513||Beardmore, Dalmuir||9.1.1913||14.5.1914||12.1914||sold for BU 10.1921|
|Inconstant||5A, 73, 77||514||Beardmore, Dalmuir||3.4.1914||6.7.1914||1/1915||sold for BU 6.1922|
|Penelope||8A, 92, 17||443||Vickers, Barrow||1.2.1913||25.8.1914||12/1914||sold for BU 10.1924|
|Phaeton||6A, 93, 45||444||Vickers, Barrow||12.3.1913||21.10.1914||2/1915||sold for BU 1.1923|
|Royalist||4A, 6A, 75||515||Beardmore, Dalmuir||3.6.1913||14.1.1915||3/1915||sold for BU 8.1922|
|Displacement normal, t||
|Displacement full, t||
|No of shafts||
4 Parsons steam turbines, 8 boilers
Arethusa, Undaunted: 4 Brown-Curtis steam turbines, 8 boilers
|Power, h. p.||
|Max speed, kts||
belt: 76 - 25, deck: 25, CT: 76, gun shields: 102
2 x 1 - 152/45 BL Mk XII, 6 x 1 - 102/45 QF Mk V, 1 x 1 - 47/50 3pdr Vickers Mk I, 2 x 2 - 533 TT
276 - 282
The grave shortage of cruisers capable of working with the Fleet was matched by a lack of ships for strengthening the flotillas. By 1911 the speed of destroyers had made it impossible for the 'Scouts' to lead a high-speed dash and that gap would widen with the introduction of what became the 'K' and 'L' classes. To examine the problem a Cruiser Committee was set up by the new First Lord, Churchill, late in 1911. Two basic lines of development were examined: a super-Swift or enlarged destroyer relying only on speed, or a super-Active, an enlarged scout with lower speed but some armour protection and a much heavier armament. As might be expected, Fisher wanted the super-Swift because of its alleged high speed (37kts), but Churchill backed the 'cruiser admirals' on the committee in their preference for an uprated 'Scout'. She would cost £285,000 as against £350,000 for a Dartmouth. By working in the armour as part of the longitudinal strength the DNC was able to increase the armour protection amidships. The E-in-C, Sir Henry Oram, proposed to use fast-running destroyer turbines and boilers to get speed up from 28 to 30 or even 31kts. The higher speed proved illusory as so much extra weight was worked into the design but even so a sea speed of 27.5kts was a great improvement over previous cruisers. Many sources quote the installed power as 30,000shp. This was the designed hp, with an extra 10,000shp load but in practice the load shp came to be used as standard. Proposed armaments were 10 102mm, as in the 'Scouts' or 5 152mm, but ultimately a compromise of 2 152mm and 6 102mm was chosen. When presented to Parliament, Churchill described them as 'light armoured cruisers', to emphasise the protection for they were the smallest British warships to be protected by vertical armour. In practice the Arethusa class proved successful in the North Sea, although very cramped as a result of wartime additions. They would not have been able to replace the 'Towns' on overseas stations, as witness the fact that the Arethusas disappeared very quickly after the war, whereas many of the older 'Towns' were kept on for some years. The mixed armament was not a success, partly because the new pattern semi-automatic 102mm QF Mk.V was prone to jam and partly because in a confused action their shell-splashes could not be distinguished from the 152mm. In 1918 the Galatea, lnconstant, Penelope, Phaeton and Royalist had the after pair of 102mm removed and an extra 152mm installed on the centreline abaft the funnels. Four of the class were the first RN cruisers to take aircraft to sea, when in 1915 they were given a sloping runway over the forecastle to enable them to launch a French monoplane. They were intended to deal with the nuisance of Zeppelins, which kept sighting the Harwich Force, but the aircraft could not gain altitude fast enough to catch the airships and in August 1915 the platforms were removed. In 1917-18 the Galatea, Phaeton, Royalist and Undaunted were fitted with a winch on the quarterdeck for towing a kite balloon, and in 1918 all seven were given flying-off platforms over the forward 152mm gun. Undaunted was completed at the end of August 1914 with her upper-works camouflaged, one of the first RN warships to be disguised in this way.
Armoured belt protected ship at full length, its thickness was 76mm abreast machinery spaces (51mm armour on 25mm plating), 51mm (38mm armour on 13mm plating) aft and 38mm (25mm armour on 13mm plating) fore. Belt was closed by aft 25mm bulkhead near stern. It extended to main deck (and to upper deck abreast machinery). Machinery and steering gear were covered by 25mm deck.
1915, all except Galatea: - 1 x 1 - 47/50; + 1 x 1 - 76/45 20cwt QF Mk I
1915, 4 ships: + flying-off platform and 1 French monoplane aircraft (it was removed from all in August)
1917, Aurora, Galatea, Inconstant, Phaeton, Royalist: + 1 x 1 - 76/45 20cwt QF Mk I
1917, Penelope, Undaunted: + 1 x 1 - 102/45 QF Mk V
1917, all: + 2 x 2 - 533 TT
1917, all except Undaunted: mine rails were fitted (70 - 74 mines).
1917 - 1918, Galatea, Phaeton, Royalist, Undaunted: + winch for towing of kite balloon
1918, Galatea, Inconstant, Penelope, Phaeton, Royalist: - 2 x 1 - 102/45; + 1 x 1 - 152/45 BL Mk XII
1918, all: + flying-off platform and 1 aircraft
Arethusa was badly damaged by gunfire of German ships in action in the Helgoland Bight 28.8.1914. She was badly damaged by mine 11.2.1916 off Felixstowe, taken in tow but ran aground on the Cutler Shoal, stern was broken. Penelope was damaged by torpedo from German submarine UB29 off Norfolk 25.4.1916 (rudder and steering gear wrecked), repaired. Undaunted was seriously damaged in collision with destroyer Landrail in April 1915, she was severely damaged again in collision with cruiser Cleopatra 24.3.1916.
Many thanks to Wolfgang Stöhr for additional information on this page.