Engineering:K VIII-class submarine

Dutch submarine K X, in Surabaya, Dutch East Indies
Class overview
Name:	K VIII class
Builders:	Koninklijke Maatschappij De Schelde, Vlissingen, Netherlands
Operators:	Royal Netherlands Navy Royal Australian Navy
Preceded by:	K V class
Succeeded by:	K XI class
Built:	1917–1923
In commission:	1922–1944
Completed:	3
Retired:	3
General characteristics
Type:	Patrol submarine
Displacement:	Surfaced: 520 long tons (528 t) standard 583 long tons (592 t) full load Submerged: 715 long tons (726 t) standard 810 long tons (823 t) full load
Length:	64.41 m (211 ft 4 in)
Beam:	5.6 m (18 ft 4 in)
Draught:	3.55 m (11 ft 8 in)
Propulsion:	K VIII 2 × 900 hp (671 kW) 8-cylinder MAN 2-stroke diesel engines K IX & K X 2 × 775 hp (578 kW) 6-cylinder Sulzer 2-stroke diesel engines All 2 × 200 hp (149 kW) electric motors 2 shafts
Speed:	K VIII 16 kn (30 km/h) surfaced 8 kn (15 km/h) submerged K IX & K X 15 kn (28 km/h) surfaced 8 kn (15 km/h) submerged
Range:	3,500 nmi (6,500 km) at 11 kn (20 km/h) surfaced 25 nmi (46 km) at 8 kn (15 km/h) submerged
Test depth:	50 m (160 ft)
Complement:	31
Armament:	4 × 450 mm (17.7 in) torpedo tubes (2 bow, 2 stern) 10 × Type III 45cm torpedoes 1 × 88 mm (3.5 in) deck gun 1 × 12.7 mm machine gun

The K VIII-class submarine was a three boat class of submarines of the Koninklijke Marine (Royal Netherlands Navy). The class varied from K V-class submarine due to the removal of two external torpedo tubes, which were removed to reduce the boats' vulnerability to depth charging. The boat had a diving depth of 50 metres (160 ft). K VIII-class submarine was built after the John Philip Holland design.

All ships were still in service at the start of World War II. During the war K IX was transferred to the Royal Australian Navy and renamed K9.

Boats

Name	Laid down	Launched	Commissioned	Decommissioned
K VIII	31 October 1917	28 March 1922	15 September 1922	15 July 1942
K IX Renamed: HMAS K9	1 March 1919	23 December 1922	21 June 1923 (Dutch navy) 22 June 1943 (Australian navy)	15 July 1942 (Dutch navy) 31 March 1944 (Australian navy)
K X	1 November 1919	2 May 1923	24 September 1923	2 March 1942