HMSR4

R-class submarine
History
United Kingdom
Name	HMSR4
Builder	Chatham Dockyard,Kent
Laid down	4 March 1917
Launched	8 June 1918
Commissioned	23 August 1919
Nickname(s)	"The Slug"
Fate	Sold, 26 May 1934
General characteristics
Class and type	R-class submarine
Displacement	410 long tons (417 t) surfaced 503 long tons (511 t) submerged
Length	163 ft 9 in (49.91 m)
Beam	15 ft 3 in (4.65 m)
Draught	11 ft 6 in (3.51 m)
Installed power	240bhp(180 kW) (diesel) 1,200 hp (890 kW) (electric)
Propulsion	1 ×diesel engine 1 ×electric motor
Speed	9.5knots(17.6 km/h; 10.9 mph) surfaced 15 knots (28 km/h; 17 mph) submerged
Range	2,400nmi(4,400 km; 2,800 mi) at 9 knots (17 km/h; 10 mph) surfaced; 60 nmi (110 km; 69 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged
Test depth	150 feet (45.7 m)
Complement	2 officers and 20ratings
Sensors and processing systems	Bowhydrophonearray
Armament	6 × bow18-inch (45 cm)torpedo tubes

HMSR4was one of 10R-class submarinebuilt for theRoyal Navyduring the First World War. The boat was not completed before the end of the war and was sold forscrapin 1934.

Design and description

The R-class submarine was designed to meet anAdmiraltyrequirement for a specialisedhunter-killer submarinewith an emphasis on submerged performance. The boats had a length of 163 feet 9 inches (49.9 m)overall,abeamof 15 feet 3 inches (4.6 m) and a meandraftof 11 feet 6 inches (3.5 m). Theydisplaced410 long tons (420 t) on the surface and 503 long tons (511 t) submerged. The R-class submarines had a crew of 2 officers and 20ratings.They had a diving depth of 150 feet (45.7 m).

For surface running, the boats were powered by a single eight-cylinder240-brake-horsepower(179 kW)diesel enginethat drove the singlepropeller shaft.When submerged it was driven by a 1,200-horsepower (895 kW)electric motor.They could reach 9.5knots(17.6 km/h; 10.9 mph) on the surface and 15 knots (28 km/h; 17 mph) underwater. On the surface, the R class had a range of 2,400nautical miles(4,400 km; 2,800 mi) at 9 knots (17 km/h; 10 mph) and 60nmi(110 km; 69 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged.

The boats were armed with six18-inch (45 cm)torpedo tubesin the bow. They carried six reload torpedoes for a grand total of a dozen torpedoes. They were equipped with an array of fivehydrophonesin the bow to allow them to locate and engage targets while submerged.

Construction and career

HMSR4was laid down on 4 March 1917 atChatham Dockyard,launchedon 8 June 1918 and commissioned on 23 August 1919. She came too late to see any combat inWorld War I,like most of the other R-class submarines. Her shape resulted in her being nicknamed "The Slug".

On 1 November 1926,R4ran aground atExmouth,Devon,England.She was refloated 10½ hours later.

R4was the only boat to survive through to the 1930s. Additions to her casing produced slightly better sea keeping at the cost of a reduced speed from 15 knots submerged to 13 knots. She was used as a fast underwater target at thePortlandanti-submarine school until 1934, then sold on 26 May 1934 to Young, Sunderland.

References

• Akermann, Paul (2002).Encyclopaedia of British Submarines 1901–1955(reprint of the 1989 ed.). Penzance, Cornwall: Periscope Publishing.ISBN1-904381-05-7.
• Colledge, J. J.;Warlow, Ben (2006) [1969].Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy(Rev. ed.). London: Chatham Publishing.ISBN978-1-86176-281-8.
• Gardiner, Robert & Gray, Randal, eds. (1985).Conway's All the World's Fighting Ships 1906–1921.Annapolis, Maryland: Naval Institute Press.ISBN0-85177-245-5.
• Harrison, A. N. (January 1979)."The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043)".RN Subs.Retrieved27 September2022.