Shipbucket

From Wiki:

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 later converted to fast second-rate anti-submarine frigates in the 1950s.

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.

O class



The O-class ships were built in two groups of four. The first group had 4.7 in guns. They were in low-angle mounts which could elevate to only 40 degrees, and were additionally fitted with a 4 in anti-aircraft gun in place of one set of torpedo tubes. The second group had 4-inch (102 mm) guns in high-angle mounts and were fitted to act as minelayers; they could be recognised 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 The latter proved to be outdated, and were replaced by 20 mm Oerlikon guns as they became available, with a total of six single mounts eventually being carried.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 in 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.

Length: 345 ft overall
Beam: 35 ft (11 m)
Draught: 11 ft 4.5 in (3.467 m) mean
Propulsion: Steam turbines, 40,000 shp (29,828 kW)
Speed: 37 knots (43 mph; 69 km/h)
Range: 497 tons of fuel oil
Complement: 176

(Krakatoa - I have doubts about the 37 knot speed, more likely 34-35 knots)


O class

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



4.7 inch-armed ships

Displacement: 1,610 tons (1,636 tonnes)
2,270 tons (2,306 tonnes) full load
Complement: 176 (217 in leader)
Armament: 4 x QF 4.7-inch (120-mm) Mk IX guns, single mounts CP Mk.XVIII
1 x QF 4 in Mk.V (102 mm L/45), mount HA Mk.III
4 x QF 2 pdr Mk.VIII (40 mm L/39), quad mount Mk.VII
Up to 6 x QF 20 mm Oerlikon, single mount P Mk.III
4 (1x4) tubes for 21 in torpedoes Mk.IX

Onslow * (ex-Pakenham), built by John Brown & Company, Clydebank, to Pakistan 1949 as Tippu Sultan, sold out
Offa, built by Fairfield Shipbuilding & Engineering Company, Govan, to Pakistan 1949 as Tariq, sold for scrap in 1959
Onslaught (ex-Pathfinder), built by Fairfield, to Pakistan 1951 as Tughril, sold out
Oribi (ex-Observer), built by Fairfield, to Turkey 1946 as Gayret, sold out

4 inch-armed ships

Displacement: 1,540 tons (1,564 tonnes)
2,220 tons (2,255 tonnes) full load
Armament: 4 x QF 4 in Mk.V (102 mm L/45), single mount HA Mk.III
4 x QF 2 pdr Mk.VIII (40 mm L/39), quad mount Mk.VII
Up to 6 x QF 20 mm Oerlikon, single mount P Mk.III
8 (2x4) tubes for 21 in torpedoes Mk.IX
Up to 60 mines (where fitted-for)

Obdurate †, built by William Denny & Brothers, Dumbarton, sold for scrap in 1964 at J Cashmore's, Newport, Monmouthshire
Obedient †, built by Denny, sold for scrap - 1964
Opportune †, built by John I. Thornycroft & Company, Woolston, sold for scrap - 1955
Orwell †, built by Thornycroft, converted to Type 16 frigate 1952, sold for scrap - 1965

* = flotilla leader, † = fitted for minelaying


P class

Displacement: 1,570 long tons (1,595 t) standard
2,175 long tons (2,210 t) full load
Armament: 4 × 4 inch guns,
1 × single QF 2 pdr "pom-pom" Mk. II
4 x 20 mm Oerlikon
2 × 4 21 in (530 mm) torpedo tubes
100 depth charges delivered from two stern traps and four throwers


They served mainly in the Mediterranean, where four ships were lost.
Pakenham * (ex-Onslow), built by Hawthorn Leslie & Company, Hebburn, damaged by gunfire from Italian Navy torpedo boats Cassiopea and Cigno off Marsala 1943-04-16, abandoned and sunk by sister ship HMS Paladin (see Battle of the Cigno Convoy)
Paladin, built by John Brown, converted to Type 16 frigate 1954, sold for scrap in 1962
Panther, built by Fairfield, bombed and sunk by German aircraft in Scarpanto Strait on 10 September 1943
Partridge, built by Fairfield, torpedoed by German Submarine U-565 off Oran, 18 December 1942
Pathfinder (ex-Onslaught), built by Hawthorn Leslie, On 11 February 1945, Pathfinder was hit by a Japanese bomber plane off Ramree, and was taken out of service. and used as an aircraft target, sold for scrap in 1948
Penn, built by Vickers Armstrongs, Walker, sold for scrap - 1949
Petard (ex-Persistent), built by Vickers Armstrongs, converted to Type 16 frigate, sold for scrap 1967
Porcupine, built by Vickers Armstrongs, torpedoed by German submarine U-602 in Mediterranean 9 December 1942 and broke in two; never repaired and hulked as Pork and Pine, sold for scrap - 1947

* = flotilla leader

As can be seen I have posted the drawings without their COA's, if someone would like to claim them and do them for me, it would be greatly appreciated.

If you wonder why Novice keeps getting credited on these drawings, I continue to use his underwater hull that was on the J-N's as well. (Copy/Paste is quicker) why reinvent the wheel.

VERY nice work!

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MS State Guard - 08 March 2014 - 28 January 2023

The Official IJN Ships & Planes List

#FJB

Great work Krakatoa!

Excellent work Nigel.
You might want to clarify the name changes though
HMS Petard was also re armed with 2 twin 4" (102mm) guns for better AA use, a modification it was intended for all of the class, but money and the end of the war put an end to the idea.
Also note that the hull of the O and P was a slightly shorter version of the hull of the pre war J, K and N classes, hence the higher bow, to keep A gun dry. The succeeding classes the Q class reverted to the original dimensions of the pre war ships.

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Thank you Kim for the crest

"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"

Thanks for the comments guys.

Novice, I did use the dimensions posted in Wiki for O&P class ships when I resized the original drawing. The drawings are shorter than the J series I did. They are much like the JB1 pre-J class design.

I used the Petard name because I knew it had been re-armed at some stage, but I have not yet been able to find a decent enough photo and/or drawing that I can do an SB drawing from. I have a photo from astern where I can see the twin 4" in B and X positions, but I can not see what is now in A and Y positions. I am picking a Hedgehog in A position and extra DC's in Y position. But need proof before I draw it.

After having such success with the O&P 4" ships it seems strange that the RN builders went back to the low angle 4.7" for the following Q-V classes. Single or twin 4" would certainly have been better. Once the 4.5" DP gun is available the destroyers armed with those become much more useful. Those same 4.5" removed from the ships refitted to Frigates end up arming the later Tribal class frigates.

Nigel I did not meant, in my comment about the ships length to imply that you have made a mistake, just as a remark for general knowledge.
The Petard was indeed, like you said, armed with the guns in B and X positions (in fact much like the later Type 16 frigates conversion with Squid in X position instead of a gun mounting. The use of the 4.7" low angle in the Q to W classes (the Z class and subsequent classes had the 4.5" gun), was to give surface fire power to the destroyers force, as they were regarded as anti-shipping force, in that big "fleet action" that the Admiralty had in mind during the inter-wars period. The RN had the 4.7" guns while likely enemies had even bigger guns (German destroyers had 5" guns, Japanese destroyers also had 5" guns and so on).

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Thank you Kim for the crest

"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"

Novice, no offence taken. My comment was for general interest as well. The 4.7" O's are very like the JB1 drawing I did, main changes are the 4" AA and the quad torpedoes in place of the quintuples, also the quad 2pdr is mounted higher for better angles of fire. As noted, the bow is better laid out. I actually think Wiki might have wrong dimensions, the J-N's are listed as 356ft, and the O/P class are supposed to be shorter, my drawing is 345ft, while Wiki says 362ft which is the Q+ classes length. Strangely enough under HMS Onslow in Wiki it gives 345ft, while under the O class heading it gives 362ft.

My take on how it looks like the Petard was with the twin 4" upgrade.

Excellent work on all of these Krakatoa.
Doubtless there are many more versions that could be drawn too given the extensive service these ships saw!

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