Danae - class cruiser The " Danae " or " D " - class was a class of light cruiser built for the Royal Navy at the end of World War I and that survived to see service in World War II . Design . The " Danaes " were based on the design of the preceding C class series , but were lengthened by to allow a sixth gun to be worked in between the bridge and the forefunnel . This gave an ' A ' , ' B ' , ' P ' , ' Q ' , ' X ' , ' Y ' arrangement . Additionally , the twin torpedo tubes in the C class were replaced by triples , giving the " Danaes " a total of twelve tubes , the heaviest torpedo armament for a cruiser at the time . Machinery and general layout was otherwise the same as the " Ceres " group of C class cruisers . However , " Danae " , " Dauntless " and " Dragon " were ordered before the " Capetown " group , and therefore did not incorporate the improved bow design of the latter ; the C class were " very " wet forwards , and in the " Capetowns " sheer was increased forwards into a knuckled " trawler bow " . Such was the success of the knuckled bow that it was incorporated into all subsequent British cruisers ( except of 1935 which was completed without ) . " Despatch " and " Diomede " had their beam increased by ½ foot to increase stability and " Dragon " and " Dauntless " were completed with a hangar for a floatplane built into the bridge , the compass platform being on top . " Delhi " , " Dunedin " , " Durban " , " Despatch " and " Diomede " were provided with flying - off platforms for a wheeled aircraft aft . " Despatch " and " Diomede " were completed with 4 inch anti - aircraft ( A / A ) guns " vis " 12 pounder ( 3 inch ) guns in their sisters and " Diomede " had ' A ' gun shipped in a weatherproof housing CP Mark XVI , an encouraging development for gun crews hitherto exposed to the worst of the elements on the fo ' c ' sle . Modifications . The lessons of the Battle of Jutland were applied and protection was improved in detail . Additional torpedo tubes were installed and depth charge throwers were also included . The Mk XII gun was retained but , in " Diomede " , a new prototype gun house ( allowing greater elevation ) was used and found to be most satisfactory . Inter - war , all ships had their anti - aircraft armament standardised as three QF 4 inch Mark V guns on mountings HA Mark III , with a QF 2 pdr Mk . II gun in each bridge wing . All aircraft arrangements were also removed , and " Dragon " and " Dauntless " had their bridges rebuilt along the lines of the rest of the class . Early modifications in World War II included the addition of Radar Type 286 air warning at the foremast head and , later , Type 273 centimetric target indication set on the searchlight platform amidships . Between 6 and 8 20 mm Oerlikon guns were generally added , replacing the old 2 pounder guns in the bridge wings , on either side of ' P ' and ' Q ' guns and on the quarterdeck . In 1942 , " Dauntless " ( and in 1943 , " Danae " ) had the aft 4 inch A / A gun replaced by a quadruple mounting Mark VII for the 2 pounder Mark VIII gun and in 1943 , " Danae " and " Dragon " had ' P ' gun and the forward pair of guns replaced by two such mountings and their Radar Type 282 equipped directors . " Dragon " and " Danae " were taken in hand again in 1943 and had the aft 4 inch / 2 pounder mountings replaced by a twin Mounting Mark XIX for the QF 4 inch Mark XVI gun . " Danae " also received twin in lieu of single Oerlikon mounts and later received a pair of single Bofors 40 mm gun s . " Diomede " landed her torpedo tubes in 1943 and received one twin mount " " Hazemeyer " Mark IV and two single mounts Mark III for Bofors guns . Between 1941 and 1942 , " Delhi " was rebuilt in the United States as an anti - aircraft vessel . All armaments were removed , and five 5 inch L / 38 Mark 12 guns in Mark 30 single mountings were added , controlled by a pair of Mark 37 Fire Control Systems . The guns were in all but the former ' P ' position . She carried a new bridge and stepped light tripod masts fore and aft , carrying Radar Type 291 air warning . Sets Type 273 target indication was added amidships and Type 285 on the Mark 37 FCS for target ranging and bearings . The light armament consisted of two quadruple 2 pounder mounts Mark VII and their directors with Radar Type 282 , a pair of twin Oerlikon mounts Mark V in the bridge wings and six single Mark III Oerlikon pedestal mounts . " Dragon " and " Durban " were expended as breakwaters in support of the Normandy landings in June 1944 , " Dragon " being replaced in Polish service by the " Danae " ( as ORP " Conrad " ) and " Despatch " was disarmed as a depot ship . Ships . Three ships were ordered in September 1916 under the War Emergency Programme : Three more ships were ordered in July 1917 under the War Emergency Programme : Finally , six more ships were ordered in March 1918 under the War Emergency Programme :