J-, K- and N-class destroyer

HMS Javelin in 1941
Class overview
Operators	Royal Navy  Royal Australian Navy  Polish Navy  Royal Netherlands Navy  Indonesian Navy
Preceded by	Tribal class
Succeeded by	L and M class
Subclasses	J, K, N
Built	1937–1941
Planned	25
Completed	24
Cancelled	1
Lost	13
Scrapped	11
General characteristics (J and K classes as built)
Type	Destroyer
Displacement	1,690 long tons (1,720 t) (standard) 2,330 long tons (2,370 t) (deep load)
Length	356 ft 6 in (108.7 m) o/a
Beam	35 ft 9 in (10.9 m)
Draught	12 ft 6 in (3.8 m) (deep)
Installed power	2 × Admiralty 3-drum boilers 44,000 shp (33,000 kW)
Propulsion	2 × shafts; 2 × geared steam turbines
Speed	36 knots (67 km/h; 41 mph)
Range	5,500 nmi (10,200 km; 6,300 mi) at 15 knots (28 km/h; 17 mph)
Complement	183 (218 for flotilla leaders)
Sensors and processing systems	ASDIC
Armament	3 × twin 4.7 in (120 mm) guns 1 × quadruple 2 pdr (40 mm (1.6 in) AA guns 2 × quadruple 0.5 in (12.7 mm) anti-aircraft machineguns 2 × quintuple 21 in (533 mm) torpedo tubes 1 × rack, 2 × throwers for depth charges
General characteristics (N class where different)
Displacement	1,773 long tons (1,801 t) (standard) 2,384 long tons (2,422 t) (deep load)
Armament	1 × single 4 in (102 mm) AA gun 4 × single 20 mm (0.8 in) Oerlikon AA guns 2 × twin 0.5 in anti-aircraft machineguns 1 × quintuple 21 in torpedo tubes 1 × rack, 2 × throwers for depth charges

The J, K and N class consisted of 24 destroyers built for the Royal Navy beginning in 1938. They were a return to a smaller vessel, with a heavier torpedo armament, after the Tribal class that emphasised guns over torpedoes. The ships were built in three flotillas or groups, each consisting of eight ships with names beginning with "J", "K" and "N". The flag superior of the pennant numbers changed from "F" to "G" in 1940.

The ships were modified throughout their wartime service, particularly their anti-aircraft (AA) guns; they were also fitted with radar.