The I-class ships were improved versions of the preceding H-class. They displaced 1370LT at standard load and 1888LT at deep load. The ships had an overall length of 323feet, a beam of 33feet and a draught of 12feet. They were powered by two Parsons geared steam turbines, each driving one propeller shaft, using steam provided by three Admiralty three-drum boilers. The turbines developed a total of 34000shp and were intended to give a maximum speed of 35.5kn. Imogen only reached a speed of from during her sea trials.[1] The ships carried enough fuel oil to give them a range of 5500nmi at . Their crew numbered 145 officers and ratings.[2]
The ships mounted four 4.7-inch (120 mm) Mark IX guns in single mounts, designated 'A', 'B', 'X' and 'Y' from bow to stern. For anti-aircraft (AA) defence, they had two quadruple mounts for the 0.5 inch Vickers Mark III machine gun. The I class was fitted with two above-water quintuple torpedo tube mounts amidships for 21inches torpedoes.[3] One depth charge rack and two throwers were fitted; 16 depth charges were originally carried,[2] but this increased to 35 shortly after the war began.[4] The I-class ships were fitted with the ASDIC sound detection system to locate submarines underwater.[5]
The ship was ordered on 30 October 1935 from Hawthorn Leslie at Hebburn under the 1935 Naval Programme. She was laid down on 18 January 1936, launched on 30 December 1936, as the seventh Royal Navy ship to carry this name,[6] and completed on 2 June 1937, at a contract price of £256,917, excluding items supplied by Admiralty such as armaments and communications equipment.[7]
Imogen was assigned to the 3rd Destroyer Flotilla of the Mediterranean Fleet upon commissioning and was initially based in Malta. Transferred to Gibraltar, she patrolled Spanish waters enforcing the policies of the Non-Intervention Committee during 1938. The ship was given a brief refit in Malta from 17 October–28 November 1938 and another at Sheerness Dockyard in August 1939.[8]
At the beginning of the Second World War Imogen returned to the Mediterranean on 3 September, but she was transferred to the Western Approaches Command for convoy escort duties two days later when Italy did not enter the war.
Together with the entire 3rd Destroyer Flotilla, the ship was transferred to the Home Fleet in October.
Off Duncansby Head during the night of 16 July 1940, Imogen collided with the light cruiser in thick fog in the North Sea whilst bound for Scapa Flow. She was badly damaged, caught fire, and sank at position 58.5667°N -56°W. Glasgow rescued 10 officers and 125 ratings; 19 men were killed in the collision.[8]
. Henry Trevor Lenton. British & Empire Warships of the Second World War. Naval Institute Press. Annapolis, Maryland. 1998. 1-55750-048-7.