I-class destroyer

The flotilla leader Inglefield
Class overview
Name:	I class
Operators:	Royal Navy  Turkish Navy
Preceded by:	G and H class
Succeeded by:	Tribal class
In commission:	1937–60
Completed:	13
Lost:	6
Scrapped:	7
General characteristics (as built)
Type:	Destroyer
Displacement:	1,370 long tons (1,390 t) (standard) 1,888 long tons (1,918 t) (deep load)
Length:	323 ft (98.5 m)
Beam:	33 ft (10.1 m)
Draught:	12 ft 5 in (3.8 m)
Installed power:	34,000 shp (25,000 kW) 3 Admiralty 3-drum boilers
Propulsion:	2 shafts; 2 geared steam turbines
Speed:	36 knots (67 km/h; 41 mph)
Range:	5,530 nmi (10,240 km; 6,360 mi) at 15 knots (28 km/h; 17 mph)
Complement:	137 (peacetime), 145 (wartime)
Sensors and processing systems:	ASDIC
Armament:	4 × single QF 4.7-inch (120 mm) Mk IX guns 2 × quadruple 0.5-inch (12.7 mm) machine guns 2 × quintuple 21-inch (533 mm) torpedo tubes 20 × depth charges, 1 rack and 2 throwers 60 mines (minelayers only)

The I-class destroyers were a group of nine destroyers, including a flotilla leader, built for the Royal Navy during the 1930s. Four similar ships were ordered by the Turkish Navy, of which two were purchased for the Royal Navy, bringing the total number of these ships in that service to 11—although three of the original ships had been lost by the time Inconstant and Ithuriel commissioned. They served in World War II and six were lost, with a seventh ship being written off as a constructive total loss.

Design

The Is were a repeat of the preceding H class, except that they had ten torpedo tubes (two banks of five) instead of eight. They incorporated the new bridge and wheelhouse layout as trialled in Hero and Hereward (except the flotilla leader Inglefield). Inglefield also had a larger tripod foremast, her sisters having pole masts. The extra weight of the torpedo tubes and fitting both minesweeps and depth charge gear (previous vessels carried one or the other) on the same hull as the H class caused a loss of stability, resulting in the need to ballast when bunker levels were low.

All ships were fitted for minesweeping and with depth charges and Asdic for anti-submarine (A/S) work and were capable of conversion to minelayers. For this, they landed 'A' and 'Y' 4.7 inch guns, the torpedo tubes and their minesweeps, allowing carriage of up to 60 mines, however only four ships ever served in this role (see below).

Turkish ships

The Turkish I-class ships were of a similar design to their British counterparts, but shipped only eight torpedoes (two banks of four), like the British H class.

Wartime modifications

Early war modifications involved replacing the after bank of torpedoes with a single QF 12 pounder (3 inch / 76 mm) anti-aircraft (A/A) gun, cutting down the after funnel and mainmast to improve the former weapon's field of fire and adding a pair of QF 20 mm Oerlikon guns in the bridge wings. Radar Type 286, a metric wavelength surface-warning set, was added as it became available, and the ineffective multiple 0.5-inch (13 mm) Vickers machine guns were replaced with further Oerlikons; the central tube was deleted from the torpedo launchers to lessen topweight. Icarus lost 'Y' gun to stow extra depth charges (for a total load of 110) and their mortars. Surviving ships received a third pair of Oerlikons, added abreast the searchlight position, and the 12 pounder gun was deleted to increase depth charge stowage. In some ships, 'A' gun was replaced with a Hedgehog ahead-throwing A/S weapon, but this alteration seems to have been reversed at a later stage. Ilex, Intrepid, Impulsive and Isis had 'B' gun removed and two QF 6 pounder 10 cwt (2.25 inch / 57 mm L/47 ) guns were added, on the twin mounting Mark I* along with a Hedgehog, the former for anti-E boat work.

Inglefield later had the second bank of torpedo tubes re-instated, but like her sisters, the central tube was removed. A 4-inch (100 mm) A/A gun was added in lieu of 'X' gun, and she had a total of six Oerlikons. Radar Type 291 was later added at the foremast head as well as "Huff-Duff" in some ships.

The ex-Turkish ships were modified along similar lines to their I-class sisters. Inconstant later received Radar Type 270, a centimetric wavelength target indication set, in lieu of the director and rangefinder on the bridge. Again, eventually six Oerlikons were carried.

Ships

Pennant number	Ship	Builder	Laid down	Launched	Commissioned	Fate
D03	Icarus †	John Brown & Company, Clydebank	9 March 1936	26 November 1936	3 May 1937	Sold for scrapping 29 October 1946.
D61	Ilex		9 March 1936	28 January 1937	7 July 1937	Sold for scrapping in Sicily 1948.
D44	Imogen	Hawthorn Leslie & Company, Hebburn	18 January 1936	30 October 1936	2 June 1937	Collided with the cruiser Glasgow 16 July 1940 and sunk.
D09	Imperial		29 January 1936	11 December 1936	30 June 1937	Severely damaged by air attack 29 May 1941 in Battle of Crete, sunk by torpedoes from Hotspur
D11	Impulsive †	J. Samuel White, Cowes	9 March 1936	1 March 1936	29 January 1938	Sold for scrapping 22 January 1946.
D02	Inglefield	Cammell Laird & Company, Birkenhead	29 April 1936	15 October 1936	25 June 1937	Sunk by German radio controlled glide bomb off Anzio, 25 February 1944
D10	Intrepid †	J. Samuel White, Cowes	6 January 1936	17 December 1936	29 July 1937	Sunk by German Ju 88 bombers off Leros, 26 September 1943
D87	Isis	Yarrow & Company, Scotstoun	5 February 1936	12 December 1936	2 June 1937	Mined and sunk off Normandy beaches, 20 July 1944.
D16	Ivanhoe †		12 February 1936	11 February 1937	24 August 1937	Mined and sunk off Texel, 1 September 1940

† = fitted as minelayers

Turkish Ships

Four ships were ordered for the Turkish Navy in 1938. Upon the outbreak of war, two were purchased by the British, but two were delivered to Turkey in 1942 as the Sultanhisar and the Demirhisar.

Pennant number	Ship	Builder	Laid down	Launched	Completed	Fate
H49	Inconstant (ex-Muavenet)	Vickers, Barrow	24 May 1939	15 December 1940	24 January 1942	Acquired 14 November 1941, ceded to Turkey 9 March 1946, sold for scrapping 1960.
H05	Ithuriel (ex-Gayret)		24 May 1939	24 February 1941	3 March 1942	Bombed at Bône 28 November 1942 and beached. Written off as constructive total loss 27 February 1943 and hulked. Sold for scrapping 25 August 1945.
H87	Sultanhisar	William Denny, Dumbarton	1939	1941	1942	Delivered to Turkey in 1942, decommissioned 1960
H80	Demirhisar		1939	1941	1942	Delivered to Turkey in 1942, decommissioned 1960

Notes

Bibliography

• English, John (1993). Amazon to Ivanhoe: British Standard Destroyers of the 1930s. Kendal, England: World Ship Society. ISBN 0-905617-64-9.
• Friedman, Norman (2009). British Destroyers From Earliest Days to the Second World War. Annapolis, Maryland: Naval Institute Press. ISBN 978-1-59114-081-8.
• Lenton, H. T. (1998). British & Empire Warships of the Second World War. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-048-7.
• 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. (1988). Destroyers of World War Two: An International Encyclopedia. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-326-1.

External links