O/P class destroyers (1941)

The O and P class were wartime destroyers of the British Royal Navy ordered in 1939, and first ships in the War Emergency Programme. The O was the first, and the P-class, the second Emergency Flotilla, to act as convoy escorts. Postwar, some were also converted as ASW frigates (second-rate) as well (Type 16). The O and P class were a near-repeat of the J class although they were smaller, and had more sheer forward as well as were the first using the Fuze Keeping Clock HA Fire Control Computer. They also diverged greatly by their simpler armament, from three twin to four or five single mounts, sometimes combining 4.7-in low angle and 4-in HA mounts. Four O-class were also delivered as minelayers.

Development

The first so-called “Intermediate destroyers” in concept went back to Admiralty discussions in 1938. These new destroyers would find a place and intermediate position between the large fleet destroyers of the Tribal class, financially unsustainable, and small escort destroyers made for pure escorts work, the Hunt class. These destroyer would be simplified in construction and armament to be built more quickly and cheaply, to replace the now outdated legacy “V” and “Modified W” classes of 1918-19.

The starting point were the recent “J” class destroyer which already were a reaction to the Tribals, being smaller and cheaper. The same hull and machinery was retaken almost without changes albeit slightly modified dimensions and a better forecastle shape, with a reworked sheer and slope forward to regain seaworthiness as the J class had a tendency to “plough” in heavy weather. This class was also planned to use alternaitve armaments, due to weapons manufactiring bottlenecks:

They were planned to use both single and twin 120mm mounts. However for simplification, the latter was abandoned. In this ultimate “intermediate” destroyer, displacement was toned down to 1500t with an economical armament of four single 120mm mounts, pompom, quadruple Vickers 12.7mm MGs and quadruple TT, and larger DC stowage. Of course by the time they were completed in 1942, this dramatically changed again.

An order for 8 ships of first “O” class in two batches was passed the very same day Britain declared war on Germany, on 03 September 1939. This was the very first naval entry of the new “Emergency war program” and thus, the O class became the “1st emergency flotilla”. Later another order for a repeat of eight ships was passed a month later; These became the “Р” class or “2nd emergency flotilla”.

War experience however soon posed the question of the adequacy of the AA armament, so already by the summer of 1940 specifications changed: One torpedo tubes bank was dropped and replacved by a twin 4-in HA (102mm) AA gun mount and the Vickers quad was later dropped and replaced when completed in 1942 by single 20 mm Oerlikon A guns. Some even wanted to rearm half these ships by twin 102mm mounts. By February 1941 eight of these ships, six of the “Р” class and two of the “O” class interchanged names when rearmed from 120mm to 102mm AA guns. Since these were lighter, this gave margin to reinforce their anti-submarine armament.

By March 1941 it has been decided to complete four “O” class as minelayers and their artillery was changed from 4.7-in (120mm) to lighter single 4-in, from seven to four, the second torpedo tubes bank back in place, and rails for 60 mines mounted at the stern deck, runing from the aft funnel. There was still the provision to mount more mines, removing the TT bank once more and a 102mm gun to compensate.

Design of the O class

The O-class were laid down in two groups of four, the first coming with 4.7 inch guns on single low-angle mounts elevating to 40 degrees, but one of their TT banks (the aftermost) was replaced by a single 4-inch anti-aircraft gun for AA defence. The second group had instead 4-inch (102 mm) guns in single high-angle mounts as dual-purpose while being fitted in addition as minelayers and thus they differed by their flat “beaver tail” stern to better drop mines, but the rails were only optionally mounted.

Indeed, if they had these mines, the weight penalty forced the landing of their “Y” (aftermost) main gun, all well as their remaining torpedo tubes banks and depth charges. The anti-aircraft armament as designed for both groups was the same, one quadruple QF 2-pounder “pom pom” and two quadruple 0.5-inch Vickers A/A machine guns. The latter was clearly outdated in 1942, so their were replaced by 20 mm Oerlikon guns when available, six installed total including two in th former platforms for the Vickers quad, abaft the bridge.

The O class all survived the war whereas five took part in the Battle of the Barents Sea, in which Onslow being damaged but survived. After it, they all received upgrades ad radar refit for which they traded their tripod masts for lattice masts, which had greater strenght.

They were built at the following yards:

John Brown: Acasta, Achates, Basisisk, Beagle (all with Brown_Curtiss turbines instead of Parsons)
Thornycroft: Acheron, and the two Canadian ones, HMCS Saguenay and Skeena.
Hawthorne Leslie: Active, Antelope, Blanche, Boadicea
Scotts: Anthony, Ardent
Vickers-Armstrong: Arrow, Keith
Palmers: Boreas, Brazen
Swan Hunter: Brillant, Bulldog

Hull and general design

The O/P class were indentical with thelselves and the J-class. As often in a wartime emergency, repeats were the easiest way to produce a design without much delays. The modifications only concerned some modularity in the gun mounts designs fore and aft to accept either 4.7 or 4 inches/45 HA QF depending on the batch. The previous J-class (K and N as well) had three twin BL 4.7 inches/45 Mark XII that were quite heavy and the overall design was seen as overweight, despite being a reaction to the Tribal class.

Emergency was thus also in the armament. Just for the sheer number of hulls needed, to replace all vintage V-W destroyers, the design opted for a return to single mounts, more available and lighter, with just a swap option between ships. Some would have the 4.7 inches Mark IX, others the dual purpose 4-in/45 Mark V HA, but all would have their pair of quadruple TT banks, alsthough this was later change. The AA and depht charge provision did not change much.

The new destroyers displaced 1,690 tons (1,717 tonnes) standard or 1,640 tons (1,666 tonnes) depending on the batch and on average 2,250 tons (2,286 tonnes) full load. This was less than the J/K class. They ended shorter as well at 345 ft (105 m) overall versus 356 ft 6 in (108.5 m), for a reduced beam as well, down to 35 ft (10.7 m) instead of 35 ft 9 in and a draught much reduced to 9 ft (2.7 m) versus 12 ft 6 in or 3.8 m. The O class equipped with the 4.7-in guns displaced 1,610 tons (1,636 tonnes) standard and 2,270 tons (2,306 tonnes) full load. The P class were even rated at 1,540 tons (1,564 tonnes) standard and 2,220 tons (2,255 tonnes) full load.

The general hull outlook was overall similar, albeit the forward sloped deck was redesigned as well as the forecastle bow flare for better seakeeping. This, cimbined with a return to lighter single mounts made a considerable difference in service. When the J/K/N were nose-heavy
and ploughed in heavy weather, the O/P class remained well-buoyant and “dry”, facilitating the work of the gunners and clearning out the bridge from massive splashes.

On that note, the O/P class had the same general superstructure design as for the K/K/N except for the mounts. Their racy profile had the same semi-clipper bow style, a rounded bow and near-constant beam. The single funnel was raked and placed just at the break of the forecastle, and the bridge was of the same wedge type standardized much earlier. The two TT banks were placed aft amidship with an intermeduate platform hosting a searchlight, small mast (to which was flew the main battle pennant) and to which were attached the wireless radio cables. On either side were located the Vickers quad HMGs. The single 40 mm pompom was located on a bandstand immediately aft of the funnel. Normal Complement was 176 officers and ratings, but the two leaders, Onslow and Pakenham, had an extra staff crew with the flotilla captain(D) plus extra accomodations for a crew of 217. Otherwise, the leaders were just the same as regular destroyers in their own class.

Powerplant

Propulsion was essentially a repeat of the J/K/N class, with two shaft propellers, 3-bladed bropnze, fixed-picth, driven by Parsons geared steam turbines, in turn fed by steam coming from two large Admiralty three-drum water-tube boilers for a total output of 40,000 shp. This procured the O/P class a top speed in excess of 36.75 kt. Some reached 38 knots on sea trials. In regular service, 35 knots was the norm.
Range was about the same as before at 3,850 nmi at 20 knots cruise speed based on fuel tanks capacity of 472 tonnes. Both O and P classes had not noted differences in performances despite diverging displacements.

Armament

The “baseline” armament for the O-class, notably for the firs batch of four (Obdurate, Obedient, Opportune, Orwell), was essentially the same as for the next eight ships of the P-class with four QF 4 in Mk.V (102 mm L/45), all single mounts HA Mk.III. Four were placed in superfiring positions fore and aft like earlier classes. The had their two twin quadruple TT banks, and a squat stern for laying mines, being equipped with rails on either side of the deck.

The second batch (Offa, Onslaught, Onslow, Oribi) had a fifth gun installed in place of the aft TT bank, leaving just one forward. In addition to this “B” 4-in Mk.V (102 mm L/45) mount HA Mk.III aft amidship, the four superfiring positions were swapped to the QF 4.7-inch (120-mm) Mk IX guns on single mounts CP Mk.XVIII with box-like masks. These low elevation mounts were intended for A/S work only. This second batch of O-class also only had a single TT bank to make room for the extra 4-in/45 HA. The P-class were like the early O class batch but with an extra 4-in/45 QF Mk V instead of the aft TT bank like the second O-class batch.

What did not change on all these three sub-variants was the AA provision, made of a single quadruple QF 2 pdr Mk.VIII (40 mm L/39) mount Mk.VII on a bandstand just aft of the funnel. If initially two quad Vickers 0.5 inches AA were planned, installed on the platform between the two TT banks (or A-bank and B-4-in/45 mount), they were removed at completion in 1942 and swapped for two single QF 20 mm Oerlikon on single mount P Mk.III and later during the war, to two twin, with the remaining four single mounts located on the bridge’s wings and lokely aft, close to “X” mount. The quad torpedo tubes were for torpedoes Mk.IX. The four throwers and two racks were for 70 depth charges.
The minelayers of the seocnd batch had squat sterns and up to 60 mines, if mounted.

BL 4.7 inches/45 QF Mark IX

The prototype was mounted on HMS Mackay. It was installed onn the A through I, O and Q through W destroyer classes as well as the ex-Brazilian (H class) and ex-Turkish (I class). The Mark XII were the twon mounts unique to the J/K/N. They had a wide and roomy gun shield, albeit the rear was open to the elements and enemy fire. It was much lighter than the twin mounts.

Specifications 4.7-in/45 QF Mark IX

Gun weight 2.963 – 2.984 tons (3,011 – 3,032 kg), 220.62 in (5.604 m), bore 212.6 in (5.400 m).
Rate Of Fire on the CPXXII single Mounting was 10 – 12 rounds per minute with trained gunners.
Shell: HE 50 lbs. (22.68 kg) or SAP 15 in (38 cm), same weight.
Muzzle Velocity 2,650 fps (808 mps). Typically these destoryers carried 200 SAP rounds and 50 HE rounds plus 50 star shell per ship.

BL 4 inches/45 HA Mark V

The base model existed from 1914 and overall 944 were manufactured. The Mark V was the last evolution in WWI, also used in WW2. Its main difference was new shells, replacing the 31 (3 c.r.h.) by the 4.38/6 c.r.h. Muzzle velocity was the same at 2,350 ft/s (720 m/s) but the range was imprpved from 28,750 ft (8,760 m) to 31,000 ft (9,400 m). Flying time to 15,000 ft or 4600m at 55° was 12.3 seconds, making the fuze setting quite important for accuracy. The four mounts had light shields enabling an elevation up to 80°, and the single “B” mounst aft amidship had none. The mount gave them a range of 31,000 ft or 9,450m. Agains ships at 44° they could hit targets at up to 16,430 yards (15,020 m).

Specifications 4-in (101.6 mm)/45 Mark V

Mass, barrel & breech 4,890 lb (2,220 kg), 15 ft 8 in (4.8 m) oa, Bore 15 ft (4.6 m) 45 cal.
Shell: 31 lb (14.1 kg) fixed QF or Separate-loading QF, HE 53.5 lbs. (24.26 kg), SAP 56 lbs. (25.4 kg) and Shrapnel
Breech horizontal sliding-block, hydro-pneumatic/hydro-spring recoil 15 inches (380 mm)
Muzzle velocity: 2,350 ft/s (716 m/s). Filling Lyddite, Amatol 5 pounds (2.27 kg).

2-pdr/39 Pompom QF Mk VIII

Specs:

Shell: 2 lb. (980 g) or 1.8 lb. (820 g) HV
Performances: 115 rpm fully automatic at 2,040 ft/s (622 m/s) or 2400 ft/s (732 m/s) for HV
Effective Range: 3,800 yards (3,475 m) or 5,000 yards (4,572 m) HV, Ceiling HV: 13,300 feet (3,960 m)

21-inches torpedo tubes

The greater change was going from triple to quadruple torpedo tubes banks. This really set apart the interwar British destroyers from all those prior and setup a new standard.
They were placed on a deck top plaform, reloadable thanks to cranes. The model used for the A and B class destroyers were relatively old. It’s unlikely oters were fitted as in WW2, these tubes were removed, first the aft bank, then the amidship one to make room for extra AA and ASW. The long range mode was so slow it made the torpedoes unusable against anything but old battleships and civilian vessels. The 40 knots mode however obliged to close the target to less than 5000 yards to be of use, a dangerous proposition unless in heavy weather and fog/night.

Specs 21 inches Mark V (1918)

Weight: 3,828 lbs. (1,736 kg)
Length: 23 ft 3 in (7.086 m)
Explosive Charge: Unknown, c600 Ibs. or 250 kgs TNT
Range and Speed settings: 5,000 yards (4,570 m)/40 knots or 13,500 yards (12,340 m)/25 knots
Power: Wet-heater

Depth Charges

Mark VII depth charge thrower being reloaded.

The usual set comprised from two to four Mark II Depth Charges Throwers (DCT) aft on the poop deck, facing either side, and one to two Depth Charge Racks (DCR) at the stern. Each carried five charges but they were railing to the aft superstructure for a total storage of 40 more DCs. Reload was made by hand, using winches, always a dangerous task with a rolling deck washed by waves. These depht charges were of the standard British type, meaning it was the Mark VII: In entered service in 1939, weighted 420 lbs. (191 kg) and carried a 290 lbs. (132 kg) TNT with a sink Rate or Terminal Velocity of 9.9 fps (3.0 mps) with a max setting at 300 feet (91 m) later 500 feet (182 m).

It’s possible they were later upgraded to the the Mark X (1944) and the Mark X*. The X** was not introduced in service in 1945 despite its great depth (down to 1,500 feet (457 m)). Squid and Hedgehog made them obsolete. There are doubts also if the Mark VII Heavy studied from 1940 and proper to depth charge launchers were used aboard, outside experimentally. Weighting 420 lbs. (191 kg) with a 290 lbs. (130 kg) TNT charge, they had a sink rate/terminal velocity of 16.8 fps (5.1 mps) and a 300 feet (91 m) max setting, helped with a 150 lbs. (68 kg) cast-iron weight attached. The idea was to reach the U-Boat faster, and it was claimed it could split open a 0.875 inch (22 mm) hull at 20 feet (6.1 m), or force to surface at 12 m or more. The game changer was a minol charge (1942) for better results, with a 30% increase.

Fire control: Fuze Keeping Clock HA Fire Control Computer

The Fuze Keeping Clock (FKC) was a simplified version of the High Angle Control System analogue fire control computer. The FKC MkII was installed first on the 1938 Tribal class, later variants on destroyers such as the J/K, L/M, and O/P. The FKC MkII was a non-tachymetric anti-aircraft fire control computer, able to accurately engage targets flying at 250 knots (460 km/h; 290 mph). The Mk V Fuze setting tray was combined with a 4 in (102 mm) anti-aircraft (A/A) round and the fuze timing data was received via electrical signals from the FKC, displayed on a dial. The operator matched these settings on the tray’s own dial, adjusting the clockwork in the A/A warhead to the calculated flight time.

Sensors

Type 271 radar

The Type 271 was a British centimetric (~10 cm/3 GHz) naval surface-search radar introduced in 1941, widely used by Royal Navy escorts to locate surfaced U-boats, even their periscopes (3 miles (4.8 km) U-Boat surfaced, or a periscope at 900 yards (820 m)). It was one of the first practical microwave radars small enough to fit on small escorts.
It was used for short-range surface search and as submarine-hunting radar. A CT could be picked up at a few miles, a periscope at several hundred yards, useful in the night. It improved resolution over older and longer-wavelength radars at night and low-visibility.
Frequency/wavelength: ~2.95–3.0 GHz (~10 cm band).
Pulse repetition: ~500 pps; pulse width commonly 0.7–1.5 µs in various marks.

Power: early sets ~5–7 kW; later “Q/Mark IV” and other upgraded models used much higher magnetron output (tens to hundreds of kW peak), increasing range and stability.
Antenna: small stacked “cheese” (sliced-parabola) antennas in a protective perspex lantern — compact enough for small-ship mounting.

Display: early sets gave range/angle on A-scope; later Q-models added a PPI (plan position indicator) for easier tactical use.
Derived/related sets: Type 272 for destroyers, less successful and Type 273 for cruisers and battleships. Replaced by the Type 276/277.

Type 285 radar

The Type 285 was a fire-control radar, same generation of centimetric radars, transforming naval gunnery and air defense in WW2.
It was used for High-Angle (HA) anti-aircraft directors and installed on the batches armed with 4-in/45 HA mounts as main armament, plus the ones swapping a TT bank for a single mount. It was deployed just as the O-P class were completed. This was an integral part of the High-Angle Control System (HACS), notably combioned with the Fuze Keeping Clock system, being fitted on new destroyers from mid-1941 onward, retrofitted to existing destroyers when possible. Frq 600 MHz, power 25 kw, range 18,000 yd (16,000 m), ceiling 15,000 ft (4,600 m) accuracy 150 yd (140 m). Later variants enable tracking targets at 500 knots (930 km/h; 580 mph), combined with Gyro Rate Units for tachometric capabilities, greatly improving ranging and accuracy.

Type 286P radar

Type 286: Naval air search radar, first destroyer set, very crude, not rotating. Full data 286P: rotating antenna, better bearing accuracy of 3-5 degrees. The Type 286 was a British naval radar derived from the RAF’s ASV Mark II radar system. Initial versions such as the Type 286M had fixed antennas, so the entire ship was turned to angle the radar beam in any direction.

The Type 286P variant had at last a rotating antenna, improving bearing accuracy to about 3–5°. It worked in the VHF/metric waveband (around 214 MHz), similar to other naval radars of that family. It was used primarily for surface-warning and as target indication rather than fire control. Since it was relatively low in frequency and had broad beamwidths, resolution and detection of small targets was poor. It used beam-switching on the receiving aerial (in earlier Type 286 versions) to help with bearing information. It was replaced in time by the Type 291 (1944-45).

Sonar Type 144

From 1943, range 2500 yards (2300 meters) to 3000 yards (2700 meters), integrated into the fire control and coupled with Hedgehog. 1st with bearing recorder, automatic scanning, turning 5 degrees after each ping, often coupled with the Type 147 “Sword” depth finding sonar with a beam steerable vertically. Also coupled with the Q attachment reducing the under hull blind spot. 60° deep vertical beam, trained with the main Type 144 transducer.

⚙ specifications O class 4.7-in 1941
Displacement	1,610 tons (1,636 tonnes), 2,270 tons (2,306 tonnes) FL
Dimensions	345 x 35 x 9ft (105 x 10.7 x 2.7 m)
Propulsion	2 shafts Adm. 3-drum WT boilers, Parsons GST 40,000 shp
Speed	36.75 knots
Range	3,850 nmi at 20 knots
Armament	4× QF 4.7-in Mk IX, 1× Mk.V L/45, 1×4 2 pdr pompom, 6x 20 mm Oerlikon, 1×4 21-in torpedoes
Sensors	Type 271, 272, 285, 291 radars, type 144 sonar
Crew	176 (217 in leader)

⚙ specifications O class 4-in 1941
Displacement	1,540 tons (1,564 tonnes), 2,220 tons (2,255 tonnes) full load
Armament	4× QF 4 in/45 Mk.V, 1×4 QF 2 pdr, 6x 20 mm Oerlikon, 2×4 21-in torpedoes, 60 mines*

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

Wartime Modifications

In 1943 all the ships having single 20mm/70 abaft the briodge were replaced by twin Mk II/IV.
In 1943-1944 they also all received two more 2 DC Thrower with 60 DCs. They also traded their type 286P radar for a type 290 radar and until 1945 those with the type 286P or type 290 were upgraded again to the type 291 radar. A few also obtanined the type 272 radar. HMS Offa, Onslaught, Onslow lost their aft 4-in/45 HA for the return of their 21-in TT bank.

After the war, Offa, Onslaught and Onslow ended the war with their four 4.7-in/45 CP Mk XVIII, a quad pompom Mk VII, two twin 20mm/70 Mk V and two single 20mm/70 Mk III Oerlikon AA guns, all their torpedo tibes, four DC Throwers and two 2 DC Racks for 60 depht charges. Some possiblu retained their Type 271 and type 272 radars, but the norm was a type 285 and type 291 radar as well as the type 144 sonar.
HMS Oribi kept her 4-in/45 HA Mk III instead of her 21-in TT bank and the same. Obdurate, Obedient, Opportune and Orwell had both TT banks mounted.

Career of the O class

HMS Onslow (Flotilla Leader) laid down as HMS Pakenham at John Brown on 1 July 1940, then swapped for the O-class and renamed, launched on 31 March 1941 and commissioned on 8 October 1941.

Offa G29 Fairfield 15 January 1940 11 March 1941 20 September 1941 To Pakistan 1949 as Tariq, sold for scrap in 1959.

Onslaught (ex-Pathfinder) G04 14 January 1941 9 October 1941 19 June 1942 To Pakistan 1951 as Tughril, sold out.

Oribi (ex-Observer) G66 15 January 1940 14 January 1941 5 July 1941 To Turkey 1946 as Gayret, sold out.

Obdurate G39 Denny 25 April 1940 19 February 1942 3 September 1942 Sold for scrap in 1964 at J Cashmore’s, Newport, Monmouthshire.

Obedient G48 22 May 1940 30 April 1942 30 October 1942 Sold for scrap – 1964.

Opportune G80 Thornycroft 28 March 1940 21 February 1942 14 August 1942 Sold for scrap – 1955.

Orwell G98 20 May 1940 2 April 1942 17 October 1942 Converted to Type 16 frigate 1952, sold for scrap – 1965.

P class:

The P class were essentially repeats of the O class, and had only the latter batch dual purpose 4 inch guns all in high-angle (HA) mounts and fitted with a new taller but lighter shield. Balance was kept and kept one torpedo tubes bank (B TT bank replaced by a 4-in gun) while having the same upgraded AA, trading their planned quand Vickers 0.5 inches AA heavy machine guns for six 20 mm Oerlikon mounts. The table below only lists true changes.

Displacement	1,690 tons (1,717 tonnes) standard, 2,250 tons (2,286 tonnes) full load
Armament	5× QF 4-in Mk.V, 1×4 QF 2 pdr Mk.VIII pompom, 6x 20 mm Oerlikon, 1×4 21-in TTs, 4 DCT, 2 DCR (70)

Wartime Modifications

In 1943-1944, Paladin, Pathfinder, Penn and Petard had their 4-in (102mm/45) HA swapped for their original quad 21-in(533mm) TT bank.
By late 1944, Petard had a swap of main guns. Instead of four single 4-in(102mm)/45, she received two twin 4-in/45 QF Mk XVI forward, plus two extra 20mm/70 Oerlikon Mk II/IV AA guns.

When the war ended, HMS Paladin and Penn had their four 4-in/45 HA Mk III and quad 40mm/39 Mk VII pompom as well as two twin 20mm/70 Mk V, two single 20mm/70 Mk III Oerlikon AA guns. They retained all their 21-in TT banks as well as their four DC Throwers, two DC Racks (70 depht charges). Their new larttice mast supported probably the type 271, type 272 but also for certain the type 285, type 291 radars and type 144 sonar. HMS Petard still had its two twin Mk XIX, quad 40mm/39 Mk VII pompom, two twin 20mm/70 Mk V, four single 20mm/70 Mk III and the same. The main artillery was the greatets difference as in the J class.

Career of the P class

Pakenham(ex-Onslow) Leader Hawthorn Leslie 6 February 1940 28 January 1941 4 February 1942 Disabled by gunfire from Italian Navy torpedo boats Cassiopea and Cigno off Marsala 16 April 1943 in the Battle of the Cigno Convoy, abandoned and scuttled by sister ship HMS Paladin following the action

Paladin G69 John Brown 22 July 1940 11 June 1941 December 1941 Converted to Type 16 frigate 1954, sold for scrap in 1962

Panther 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.

Partridge G30 3 June 1940 5 August 1941 22 February 1942 Torpedoed by German Submarine U-565 off Oran, 18 December 1942.

Pathfinder 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.

Penn G77 Vickers Armstrongs 26 December 1939 12 February 1941 10 February 1942 Sold for scrap – 1949.

Petard G56 27 March 1941 15 June 1942 Converted to Type 16 frigate, sold for scrap 1967.

Porcupine G93 10 June 1941 31 August 1942 Torpedoed by German submarine U-602 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.

Read More/Src

Books

Destroyers of the Royal Navy, 1893–1981, Maurice Cocker, Ian Allan
Connell, G. G. (1982). Arctic Destroyers: The 17th Flotilla. London: William Kimber.
English, John (2001). Obdurate to Daring: British Fleet Destroyers 1941–45. Windsor, UK: World Ship Society.
Friedman, Norman (2006). British Destroyers & Frigates: The Second World War and After. NIP
Lenton, H. T. (1998). British & Empire Warships of the Second World War. NIP
March, Edgar J. (1966). British Destroyers: A History of Development, 1892–1953. London: Seeley Service
Raven, Alan; Roberts, John (1978). War Built Destroyers O to Z Classes. Bivouac Books.
Rohwer, Jürgen (2005). Chronology of the War at Sea 1939–1945: The Naval History of WW2 NIP
Whitley, M. J. (1988). Destroyers of WW2: An International Encyclopedia. NIP

Links

/uboat.net P class DDs
/uboat.net O class DDs
British Mechanical Computers RN
navypedia.org
en.wikipedia.org
iwm.org.uk

Model Kits

smmlonline.com/reviews
O class DDs
modelwarships.com

3D