O and P-class destroyer explained

The O and P class was a class of destroyers of the British Royal Navy. Ordered in 1939, they were the first ships in the War Emergency Programme, also known as the 1st and 2nd Emergency Flotilla, respectively. They served as convoy escorts in World War II, and some were subsequently converted to fast second-rate anti-submarine frigates in the 1950s.

Design

The O and P class were based on the hull and machinery of the preceding J class, but with more sheer forward to counter the poor riding qualities of the Js. These ships used the Fuze Keeping Clock HA Fire Control Computer.^[1]

O class

The O-class ships were built in two groups of four. The first group had 4.7 inch guns. They were in low-angle mounts which could elevate to only 40 degrees, and were additionally fitted with a 4-inch anti-aircraft gun in place of one set of torpedo tubes. The second group had 4adj=onNaNadj=on guns in high-angle mounts and were fitted to act as minelayers; they could be recognized by the flat "beaver tail" stern over which the mines were dropped.

When carrying mines they had to land Y gun, their torpedo tubes and depth charges. The designed anti-aircraft armament was one quadruple QF 2-pounder "pom pom" and a pair of quadruple 0.5-inch Vickers A/A machine guns. The latter proved to be outdated, and were replaced by 20 mm Oerlikon guns as they became available, with a total of six single mounts eventually being carried.

P class

The P class were repeats of the O class, armed entirely with 4 inch guns, in high-angle mounts fitted with a new tall design of shield which did not require the ships to lose a set of torpedo tubes to take on further AA guns.

Ships

O class

All ships survived the war. Five of them were involved in the Battle of the Barents Sea, Onslow being badly damaged. After the battle, the ships were refitted with tall lattice masts instead of the normal mast.

Construction data for 4.7-inch-armed ships

Name	Pennant number	Builder	Laid down	Launched	Completed	Fate
	G17	John Brown	1 July 1940	31 March 1941	8 October 1941	To Pakistan 1949 as Tippu Sultan, sold out
	G29	Fairfield	15 January 1940	11 March 1941	20 September 1941	To Pakistan 1949 as Tariq, sold for scrap in 1959.
	G04		14 January 1941	9 October 1941	19 June 1942	To Pakistan 1951 as Tughril, sold out.
	G66		15 January 1940	14 January 1941	5 July 1941	To Turkey 1946 as Gayret, sold out.

Construction data for 4-inch-armed ships

Name	Pennant number	Builder	Laid down	Launched	Completed	Fate
	G39	Denny	25 April 1940	19 February 1942	3 September 1942	Sold for scrap in 1964 at J Cashmore's, Newport, Monmouthshire.
	G48		22 May 1940	30 April 1942	30 October 1942	Sold for scrap - 1964.
	G80	Thornycroft	28 March 1940	21 February 1942	14 August 1942	Sold for scrap - 1955.
	G98		20 May 1940	2 April 1942	17 October 1942	Converted to Type 16 frigate 1952, sold for scrap – 1965.

All of the O-class ships with 4-inch armament were fitted for minelaying.

P class

They served mainly in the Mediterranean, where four ships were lost.

Construction data for 4-inch-armed ships

Name	Pennant number	Builder	Laid down	Launched	Completed	Fate
(ex-Onslow)	G06	Hawthorn Leslie	6 February 1940	28 January 1941	4 February 1942	Disabled by gunfire from Italian Navy torpedo boats and off Marsala 16 April 1943 in the Battle of the Cigno Convoy, abandoned and scuttled by sister ship HMS Paladin following the action
	G69	John Brown	22 July 1940	11 June 1941	December 1941	Converted to Type 16 frigate 1954, sold for scrap in 1962
	G41	Fairfield	15 July 1940	28 May 1941	12 December 1941	Bombed and sunk by German Junkers Ju 87 'Stuka' aircraft in Scarpanto Strait on 10 September 1943.
	G30		3 June 1940	5 August 1941	22 February 1942	Torpedoed by German Submarine U-565 off Oran, 18 December 1942.
	G10	Hawthorn Leslie	5 March 1940	10 April 1941	13 April 1942	On 11 February 1945, Pathfinder was hit by a Japanese bomber off Ramree, and was taken out of service. She was used as an aircraft target, sold for scrap in 1948.
	G77	Vickers Armstrongs	26 December 1939	12 February 1941	10 February 1942	Sold for scrap - 1949.
	G56			27 March 1941	15 June 1942	Converted to Type 16 frigate, sold for scrap 1967.
	G93			10 June 1941	31 August 1942	Torpedoed by German submarine in the Mediterranean on 9 December 1942 which broke her in two; she was never repaired, but hulked as Pork and Pine, sold for scrap, 1947.

See also

• Type 16 frigate

postwar conversion of some O and P class vessels into second-rate fast anti-submarine frigates.

References

• Destroyers of the Royal Navy, 1893–1981, Maurice Cocker, Ian Allan,
• Book: Connell. G. G.. Arctic Destroyers: The 17th Flotilla. 1982. William Kimber. London. 0-7183-0428-4.
• Book: English, John. Obdurate to Daring: British Fleet Destroyers 1941–45. World Ship Society. Windsor, UK. 2001. 978-0-9560769-0-8.
• Book: Friedman, Norman. British Destroyers & Frigates: The Second World War and After. Naval Institute Press. Annapolis, Maryland. 2006. 1-86176-137-6.
• Book: Lenton, H. T.. Henry Trevor Lenton. British & Empire Warships of the Second World War. Naval Institute Press. Annapolis, Maryland. 1998. 1-55750-048-7.
• Book: March, Edgar J.. British Destroyers: A History of Development, 1892–1953; Drawn by Admiralty Permission From Official Records & Returns, Ships' Covers & Building Plans. 1966. Seeley Service. London . 164893555.
• Book: Raven. Alan. Roberts. John . War Built Destroyers O to Z Classes. Bivouac Books. London. 1978. 0-85680-010-4.
• Book: Rohwer, Jürgen. Chronology of the War at Sea 1939–1945: The Naval History of World War Two. Naval Institute Press. Annapolis, Maryland. 2005. Third Revised. 1-59114-119-2.
• Book: Whitley, M. J.. Destroyers of World War Two: An International Encyclopedia. Naval Institute Press. 1988. 0-87021-326-1. Annapolis, Maryland. Michael J. Whitley.

Notes and References

1. Destroyer Weapons of WW2, Hodges/Friedman,