Taranto's fixed defences included twenty-one dual-purpose 4-inch guns, eighty-four 20 mm weapons, 109 13.2 mm machine guns and searchlights before the ships' own armament was counted. Half the ships' anti-aircraft mounts were meant to be manned continuously, rising to full secondary-armament readiness at dawn and dusk. The Italian 90 mm gun offered long range, high velocity and accuracy, but its tri-axially stabilised mounting was mechanically complex. If an axis failed or drifted, the mount could move differently from the ship and become harder to aim. That problem mattered less in harbour, although complete breakdown still required manual aiming by crews unused to it. Individual guns and ships could be effective when their equipment worked, so performance was uneven. Repeated nights on duty also encouraged fatigue and reduced alertness, even though crews and ready-use ammunition should have remained close to their guns.
Chapter · 1:12:46-1:18:10
Readiness and complex mounts weaken Italian anti-aircraft fire
Taranto had dense gun coverage and partially manned weapons around the clock, but complicated stabilised mounts and accumulated fatigue made readiness uneven.