BL 5.5-inch Mk I naval gun

BL 5.5-inch Mark I
BL 5.5-inch Mark I
	One of HMS Chester's 5.5-inch guns at the Imperial War Museum, London
Type	Naval gun, Coastal defence
Place of origin	UK
Service history
In service	1913–1954
Wars	World War One; World War Two
Production history
Designer	Coventry Ordnance Works
Designed	1913
Manufacturer	Coventry Ordnance Works
No. built	81
Specifications
Mass	13,955 lbs (6,330 kg)
Length	6.985 metres (275.0 in) bore (50 cal)
Shell	82 pounds (37.19 kg)
Calibre	5.5-inch (140 mm)
Breech	Welin breech block with Holmstrom mechanism
Elevation	-7 degrees to +30 degrees depending on mount
Rate of fire	12 rounds per minute
Muzzle velocity	2,790 f/s (850 m/s)
Effective firing range	16,250 m at 30-degree elevation

The Breech Loading 5.5-inch Mk I was a naval gun used by the British Royal Navy during both World Wars.

Naval history

This weapon was developed by Coventry Ordnance Works in 1913 and offered to the Greek Navy as main armament for two new cruisers building at Cammell Laird. On the outbreak Of World War I the two ships were purchased by Britain as HMS Chester and HMS Birkenhead. The RN was happy with the performance of the gun as it was significantly lighter than the standard 6 inch gun and fired an 82 lb shell rather than the 100 lb shell of the 6 inch weapon. It therefore had a higher rate of fire with little loss in hitting power. The British ordered more guns as secondary armament for HMS Furious and HMS Hood. A total of 81 guns were made and were used on the following ships: HMS Chester, HMS Birkenhead, HMS Furious, HMS Hood, and HMS Hermes.

Guns removed from Chester, Birkenhead and Furious were used to arm Armed Merchant cruisers: HMS Laurentic and HMS Montclare.

Coast defence gun

In 1940, the 5.5 inch guns were removed from HMS Hood in a refit. Two were installed in Hood Battery on Ascension Island and remain there today. A pair were installed in specially built casemates on the roof of Coalhouse Fort in Essex, overlooking the Thames.^[4] Guns from the Hood also went to Bognor Regis, Pevensey, North Foreland, Dover and Folkestone.^[5]

Notable actions

The gun Jack Cornwell served in his Victoria Cross action on the forecastle of HMS *Chester*

Boy Seaman First Class Jack Cornwell was posthumously awarded the Victoria Cross for heroism in serving his gun on HMS Chester during the Battle of Jutland on 31 May 1916.

Surviving examples

The gun served by Jack Cornwell VC is preserved in the Imperial War Museum in London.^[1]
Fort Bedford, Cross Hill, Ascension Island has two guns from HMS Hood
Fort Skansin, Tórshavn, Streymoy Island, Faroe Islands, has two guns from HMS Furious

Notes

^ ^a ^b Imperial War Museum (2012). "Naval BL 5.5 in Mk I Gun with Mk I pedestal mount". Imperial War Museum Collections Search. Retrieved 6 February 2012.
^ ^a ^b ^c Campbell, Naval Weapons of WWII, p.40.
^ Di Giulian
^ English Heritage (2008). "PastScape: Coalhouse Fort". National Monuments Record: PastScape. English Heritage. Archived from the original on 2 November 2013. Retrieved 10 February 2012. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
^ HMS Hood Association (4 April 2010). "HMS Hood Technical Specifications & Armament Information: Secondary/Dual Purpose Guns". Retrieved 10 February 2012.

References

Tony DiGiulian, British 5.5"/50 (14 cm) BL Mark I

Bibliography

Campbell, John (1985). Naval Weapons of World War Two. Naval Institute Press. ISBN 0-87021-459-4.

External links

[iwm-1] Imperial War Museum (2012). "Naval BL 5.5 in Mk I Gun with Mk I pedestal mount". Imperial War Museum Collections Search. Retrieved 6 February 2012.

[Campbell,_p.40-2] Campbell, Naval Weapons of WWII, p.40.

[3] Di Giulian

[4] English Heritage (2008). "PastScape: Coalhouse Fort". National Monuments Record: PastScape. English Heritage. Archived from the original on 2 November 2013. Retrieved 10 February 2012. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)

[5] HMS Hood Association (4 April 2010). "HMS Hood Technical Specifications & Armament Information: Secondary/Dual Purpose Guns". Retrieved 10 February 2012.

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v t e British Empire naval weapons of the First World War
Monitor guns	BL 9.2-inch Mk VI BL 9.2-inch Mk VIII BL 9.2-inch Mk X BL 9.2-inch Mk XII BL 12-inch Mk VIII BL 14-inch Mk II (US built) BL 15-inch Mk I BL 18-inch Mk I
Capital ship main armament	Vickers 10-inch 45 cal. EOC 10-inch 45 cal. BL 12-inch Mk VIII BL 12-inch Mk IX BL 12-inch Mk X BL 12-inch Mk XI & XII EOC 12-inch 45 cal. Mk XIII BL 13.5-inch Mk I – IV BL 13.5-inch Mk V BL 13.5-inch Mk VI EOC 14-inch 45 cal. Mk I BL 15-inch Mk I
Armoured cruiser main armament	BL 7.5-inch Mk I BL 9.2-inch Mk X BL 9.2-inch Mk XI
Secondary armament and light cruiser main armament	QF 12-pounder 18 cwt QF 14-pounder Maxim-Nordenfelt QF 14-pounder Mk I & II QF 4-inch Mk III BL 4-inch Mk VII QF 4-inch Mk V BL 4-inch Mk IX BL 5.5-inch Mk I QF 6-inch Mk I – III BL 6-inch Mk VII BL 6-inch Mk XI BL 6-inch Mk XII BL 6-inch Mk XIII-XVIII BL 7.5-inch Mk II – Mk V
Destroyer and small cruiser armament	QF 12-pounder 12 cwt Mk II QF 4-inch Mk III BL 4-inch Mk VIII QF 4-inch Mk IV BL 4.7-inch Mk I
Merchant ship armament	QF 4.7-inch Mk I – IV QF 4.7-inch Mk V*
Submarine guns	BL 4-inch Mk XI QF 4-inch Mk XII
Anti-aircraft guns	QF 2-pounder "pom-pom" Mk II QF 3-inch 20 cwt QF 4-inch Mk V
Light weapons	.303 Vickers machine gun QF 3-pounder Hotchkiss QF 3-pounder Vickers QF 6-pounder Hotchkiss
Torpedoes	18-inch Mk V – VIII 21-inch Mk II 21-inch Mk IV
Mines	Spherical Mk I, II and III Vickers Elia mine Type H mine
Anti-submarine weapons	Type A Depth charge Type B Depth charge Type C Depth charge Type D Depth charge Type E Depth charge Type F Depth charge Type G Depth charge Cruiser Mine 7.5-inch howitzer
Landing guns	QF 12-pounder 8 cwt