BL 4-inch Mk VIII naval gun
Appearance
Ordnance BL-4-inch Mk VIII naval gun | |
---|---|
![]() Forward gun of HMS Defender | |
Type | Naval gun |
Service history | |
In service | 1908–1945 |
Used by | United Kingdom Australia |
Wars | World War I – World War II |
Production history | |
Designed | 1904[1] |
No. built | Mk VIII: 246 Mk XI: 30[1] |
Variants | Mk VIII – Mk XI[1] |
Specifications | |
Mass | 2,912 pounds (1,320 kg) (barrel & breech)[2] |
Barrel length | 159.2 inches (4.044 m) bore (40 calibres)[2] |
Shell | 31 pounds (14.06 kg) Common pointed, Common lyddite[2] |
Calibre | 4 inches (101.6 mm) |
Breech | Welin, single-motion screw[2] |
Elevation | -10° to +20°[1] |
Rate of fire | 6-8 RPM[1] |
Muzzle velocity | 2,287 feet per second (697 m/s)[3] |
Maximum firing range | 10,210 yards (9,340 m)[1] |
The BL 4-inch Mark VIII naval gun[note 1] was a British medium-velocity wire-wound naval gun introduced in 1908 as an anti-torpedo boat gun in smaller ships whose decks could not support the strain of the heavier and more powerful Mk VII gun.[2]
Mk VIII history
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/c8/BL_4_inch_Mk_VIII_gun_breech_closeup_HMAS_Huon_1919_AWM_EN0319.jpg/220px-BL_4_inch_Mk_VIII_gun_breech_closeup_HMAS_Huon_1919_AWM_EN0319.jpg)
Breech of gun on HMAS Huon in March 1919
The gun succeeded the QF 4-inch Mk III, whose 25-pound (11 kg) shell had been considered insufficiently powerful for its intended role. The BL Mk VIII fired a 31-pound (14 kg) shell. It armed the following warships :
- HMS Swift laid down 1905
- Tribal-class destroyers from HMS Saracen (1908) onwards.
- Beagle-class destroyer of 1909
- Acorn-class destroyers of 1910
- Acheron-class destroyers of 1910
- River-class torpedo-boat destroyers (Australia) of 1910.
The gun was succeeded in its class from 1911 by the QF 4-inch Mk IV.
In World War II many guns were used to arm merchant ships.
Mk XI submarine gun
[edit]A Mark XI-variant was adapted to arm the K-class submarines laid down 1915.
See also
[edit]- List of naval guns
- German 10.5 cm SK L/40 naval gun – firing slightly heavier shell
Notes
[edit]- ^ Mark VIII = Mark 8. Mark XI = Mark 11. Britain used Roman numerals to denote marks (models) of ordnance until after World War II. This was the eighth model of British BL 4-inch gun.
References
[edit]Sources
[edit]External links
[edit]![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
Wikimedia Commons has media related to BL 4 inch Mk VIII naval gun.
- Tony DiGiulian, British 4"/40 (10.2 cm) BL Mark VIII and Mark XI