QF 12 pounder 18 cwt naval gun

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Ordnance QF 12 pounder 18 cwt
QF 12 pdr 18 cwt guns for HMS Shannon Vickers Works LOC ggbain 19618.jpg
On roof of BL 7.5 inch gun turret for HMS Shannon under construction at the Vickers works, Barrow
Type Naval gun
Place of origin United Kingdom United Kingdom
Service history
In service 1906–192?
Used by Royal Navy
Wars World War I
Production history
Designer Elswick Ordnance Company
Designed 189?
Specifications
Weight Gun & breech: 2,016 lb (914 kg)
Barrel length Bore: 150 inch (3.81 m) (50 calibres)

Shell Separate QF 12.5 lb (5.66 kg)
Calibre 3 in (76 mm)
Rate of fire 20 rd/min[1]
Muzzle velocity 2,600 ft/s (790 m/s)[2]
Effective firing range 9,300 yards @ +20°
(8,500 m @ +20°)

The QF 12 pounder 18 cwt gun was a 3 inch high-velocity naval gun used to equip larger British warships such as battleships for defence against torpedo boats. 18 cwt referred to the weight of gun and breech (18 × 112 lb = 2,016 lb or 914 kg), to differentiate the gun from others that also fired the "12 pound" (actually 12.5 lb or 5.7 kg) shell.

Service[edit]

Royal Navy service[edit]

Two guns mounted on roof of "X" turret, HMS Dreadnought
Front view, on roof of one of Dreadnought's turrets

Guns were mounted in:[3]

The gun was superseded in the anti-torpedo boat role on new capital ships from 1909 onwards by the far more powerful BL 4-inch Mk VII gun.

World War I land service[edit]

East Africa, circa 1916

In World War I four guns were landed for service in the East Africa campaign, on 10 February 1916, and were used until September. They constituted the 9th Field Battery manned by Royal Marines. They were originally towed by oxen and later by Napier lorries.[4]

Ammunition[edit]

The gun fired the same 12.5 lb 3-inch (76 mm) shells as the other British "QF 12 pounder" guns, but used its own larger separate cartridge case to accommodate a larger quantity of cordite propellant.

QF12pdr18cwtCartridge2lb12ozMkIIN.jpg
QF12&14pdrCPMkIIShellDiagram.jpg
QF12pdrLydditeShellMkIIMkIII.jpg
12pdrCommonLydditeMkIVShellDiagram.jpg
QF12pdrShrapnelMkIXShell1918.jpg
2 lb 12 oz (1.25 kg) cordite Cartridge Mk II, 1914
Mk II common pointed shell
Mk II & Mk III Common Lyddite shell
Mk IV Common Lyddite shell with internal night tracer, 1914
Mk IX Shrapnel shell, 1918

See also[edit]

Notes[edit]

  1. ^ 20 rounds per minute is quoted in Elswick gun tables of 1901, and may be considered optimistic
  2. ^ 2600 ft/s: Range Tables for His Majesty's Fleet, 1910 February, 1911 with 2 lb 12 oz (1.25 kg) cordite MD propellant. The gun first appears in Elswick gun Tables as quoted in Brasseys Naval Annual 1901 with a maximum muzzle velocity 2800 ft/s with "battering" charge of 3 lb cordite (Mk I), but this is not the charge adopted for British service.
  3. ^ The Sight Manual 1916
  4. ^ Farndale 1988, pages 316, 391. Farndale, quoting from the Official History, states they were from HMS Pegasus, but it did not carry these guns.

References[edit]

External links[edit]