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.
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.