The O and P class was a
class of
destroyer
In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort
larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...
s 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
An anti-submarine weapon (ASW) is any one of a number of devices that are intended to act against a submarine and its crew, to destroy (sink) the vessel or reduce its capability as a weapon of war. In its simplest sense, an anti-submarine weapo ...
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.
[Destroyer Weapons of WW2, Hodges/Friedman, ]
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
Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...
gun in place of one set of torpedo tubes. The second group had 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 naval gun, QF 2-pounder "pom pom" and a pair of quadruple Vickers .50 machine gun, 0.5-inch Vickers A/A machine guns. The latter proved to be outdated, and were replaced by Oerlikon 20 mm cannon, 20 mm Oerlikon guns as they became available, with a total of six single mounts eventually being carried.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.
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.
See also
*Type 16 frigate: postwar conversion of some O and P class vessels into second-rate fast anti-submarine frigates.
Notes
References
* ''Destroyers of the Royal Navy, 1893–1981'', Maurice Cocker, Ian Allan,
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External links
{{WWII British ships
Destroyer classes
O and P-class destroyers,
Ship classes of the Royal Navy