HMS B4

History
United Kingdom
Name	HMS B4
Builder	Vickers
Launched	14 November 1905
Completed	28 January 1906
Fate	Sold for scrap, 1 April 1919
General characteristics
Class & type	B-class submarine
Displacement	287 long tons (292 t) surfaced 316 long tons (321 t) submerged
Length	142 ft 3 in (43.4 m)
Beam	12 ft 7 in (3.8 m)
Draught	11 ft 2 in (3.4 m)
Installed power	600  bhp (450 kW) petrol 180 hp (130 kW) electric
Propulsion	1 × 16-cylinder Vickers petrol engine 1 × electric motor
Speed	12  kn (22 km/h; 14 mph) surfaced 6.5 kn (12.0 km/h; 7.5 mph) submerged
Range	1,000  nmi (1,900 km; 1,200 mi) at 8.7 kn (16.1 km/h; 10.0 mph) on the surface
Test depth	100 feet (30.5 m)
Complement	2 officers and 13 ratings
Armament	2 × 18 in (450 mm) bow torpedo tubes

HMS B4 was one of 11 B-class submarines built for the Royal Navy in the first decade of the 20th century. The boat survived the First World War and was sold for scrap in 1919.

Design and description

The B class was an enlarged and improved version of the preceding A class. The submarines had a length of 142 feet 3 inches (43.4 m) overall, a beam of 12 feet 7 inches (3.8 m) and a mean draft of 11 feet 2 inches (3.4 m). They displaced 287 long tons (292 t) on the surface and 316 long tons (321 t) submerged. The B-class submarines had a crew of two officers and thirteen ratings. ^[1]

For surface running, the boats were powered by a single 16-cylinder 600- brake-horsepower (447 kW) Vickers petrol engine that drove one propeller shaft. When submerged the propeller was driven by a 180-horsepower (134 kW) electric motor. They could reach 12 knots (22 km/h; 14 mph) on the surface and 6.5 knots (12.0 km/h; 7.5 mph) underwater. ^[1] On the surface, the B class had a range of 1,000 nautical miles (1,900 km; 1,200 mi) at 8.7 knots (16.1 km/h; 10.0 mph). ^[2]

The boats were armed with two 18-inch (450 mm) torpedo tubes in the bow. They could carry a pair of reload torpedoes, but generally did not as they would have to remove an equal weight of fuel in compensation. ^[3]

Construction and career

B4 was built by Vickers at their Barrow-in-Furness shipyard, launched on 14 November 1905 and completed on 28 January 1906. ^[4]

B4 collided with a dredger when entering Portsmouth harbour on 21 July 1906 and was badly damaged as a result, having to be beached before being taken into dry dock for repair. ^[5] When the war began in 1914, the boat was assigned to defend the Straits of Dover. B4 was sold for breaking up on 1 April 1919 to the Ardrossan Dry Dock Co.

Notes

1. Gardiner & Gray, p. 87
2. Akermann, p. 123
3. Harrison, Chapter 27
4. Harrison, A. N. (2018) [1979, London: Ministry of Defence]. "Appendix I: List of RN Submarines in the 1901 to 1936 Programmes" (PDF). BR3043: The Development of British Submarines: From Holland No. 1 (1901) to HMS Porpoise (1930). RN Subs: Website of the Barrow Submariners Association. Retrieved 25 March 2018.
5. "Naval Matters—Past and Prospective: Portsmouth Dockyard". The Marine Engineer and Naval Architect. Vol. 29. 1 September 1906. p. 41.

References

• Akermann, Paul (2002). Encyclopaedia of British Submarines 1901–1955 (reprint of the 1989 ed.). Penzance, Cornwall: Periscope Publishing. ISBN   1-904381-05-7.
• Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN   0-85177-245-5.
• Harrison, A. N. (January 1979). "The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043)". United Kingdom Ministry of Defence. Retrieved 16 September 2019– via RN Subs.
• Kemp, Paul & Jung, Peter (1989). "Five Broken Down B Boats: British Submarine Operations in the Northern Adriatic 1915–1917". Warship International. XXVI (1): 10–29. ISSN   0043-0374.
• Wilson, Michael (1981). "The British 'B' Class Submarine". In Roberts, John (ed.). Warship Volume V. London: Conway Maritime Press. pp. 38–44, 74–79. ISBN   0-85177-244-7.