QF 12 pounder 18 cwt naval gun

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.

QF 12 pounder 18 cwt naval gun
Class Vehicle
Type Towed Artillery
Manufacturer Elswick Ordnance Company
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1906
Country Name Operational Year Retirement Year
United Kingdom - UK (Great Britain) 1906 View
ManufacturerName Production From Production To Quantity
Elswick Ordnance Company View

Royal Navy service

Guns were mounted in:

  • HMS Dreadnought commissioned 1906
  • The last three King Edward VII-class battleships—HMS Britannia, HMS Africa, and HMS Hibernia, commissioned 1906–1907
  • Lord Nelson-class battleships commissioned 1908
  • Minotaur-class armoured cruisers commissioned 1908–1909
  • The gun was superseded in the anti-torpedo boat role on new capital ships from 1909 onwards by the far more powerful BL 4-inch Mk VII gun.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

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.

Fourteen of these guns were mounted in coast defence batteries in the 'Middle Line' of the defences of the Firth of Forth when it was established in 1915 (the batteries on Inchcolm (8 guns), Inchmickery (4) and Cramond Island (2). During the general revision of the defences in 1916/17 two of the guns were removed to store, four moved to other batteries (Hound Point and Downing Point). The document setting out the armaments of the Forth differentiate clearly between the 12cwt and 18cwt types, both of which were in use in the fortress.

Type Naval gun
Place of origin United Kingdom
Service history
In service 1906–192?
Used by Royal Navy
Wars World War I
Production history
Designer Elswick Ordnance Company
Designed 189?
Weight Gun & breech: 2,016 lb (914 kg)
Barrel length Bore: 150 inch (3.81 m) (50calibres)
Shell Separate QF 12.5 lb (5.66 kg)
Calibre 3 in (76 mm)
Rate of fire 20 rd/min
Muzzle velocity 2,600 ft/s (790 m/s)
Effective firing range 9,300 yards @ +20°
(8,500 m @ +20°)

End notes