Why the 3-inch gun suited air defence in 1916

The 3-inch gun, also identified here as the 12-pounder or 76 mm gun, offered enough reach and destructive effect to threaten reconnaissance airships. A Zeppelin could report a fleet's position to submarines or the High Seas Fleet without approaching closely. The calibre was also near the upper end at which a rapid-firing mechanism was considered practical. Pom-pom development extended beyond the 1-pounder and 2-pounder to work on 4-pounder and 6-pounder variants, with a 12-pounder considered in theory. How far the largest designs progressed remains uncertain. Existing Royal Navy use against small craft meant that trained crews, ammunition, barrels and maintenance support were already available. Adapting the mounting therefore offered a practical route to an anti-aircraft weapon without establishing an entirely new support system.