The gun was based on the barrel of the QF 4-inch Mk V and the breech mechanism of the BL 4-inch Mk VIII and was first introduced in World War I on capital ships as secondary armament in triple-gun mountings, intended to provide rapid concentrated fire.
This turned out to be unworkable in practice.
Jane's Fighting Ships of 1919 commented, "4-inch triples are clumsy and not liked.
They are not mounted in one sleeve; have separate breech mechanism, a gun crew of 23 to each triple".
Guns were thereafter used in single-gun mountings, typically on smaller ships as the main armament.
The gun was based on the barrel of the QF 4-inch Mk V and the breech mechanism of the BL 4-inch Mk VIII and was first introduced in World War I on capital ships as secondary armament in triple-gun mountings, intended to provide rapid concentrated fire. This turned out to be unworkable in practice. Jane's Fighting Ships of 1919 commented, "4-inch triples are clumsy and not liked. They are not mounted in one sleeve; have separate breech mechanism, a gun crew of 23 to each triple". Guns were thereafter used in single-gun mountings, typically on smaller ships as the main armament.
BL 4-inch Mk IX naval gun