QF 4.7-inch Mk V naval gun

The QF 4.7 inch Gun Mark V originated as a 4.7 in (120 mm) 45-calibre naval gun designed by the Elswick Ordnance Company for export customers and known as the Pattern Y.^[3]

QF 4.7 inch Gun Mk V
On troopship Orca, March 1919
Type	Naval gun Coast defence gun
Place of origin	United Kingdom Japan
Service history
In service	1900–1945
Used by	British Empire
Wars	World War I World War II
Production history
Designer	Elswick Ordnance
Designed	ca. 1895
Variants	Mark V, Mark V*
Specifications
Mass	Barrel & breech 5,936 pounds (2,693 kg)[1]
Barrel length	212.6 inches (5.40 m) (45 cal)[1]
Shell	Separate loading QF 45 pounds (20.41 kg) Common Pointed, Lyddite
Calibre	4.724 inches (120 mm)
Breech	single motion interrupted screw
Recoil	8 inch[1]
Elevation	-10° to +20°[2]
Rate of fire	Approx. 8-10 rounds per minute[3]
Muzzle velocity	2,350 feet per second (720 m/s)[4]
Maximum firing range	16,500 yards (15,100 m)[1]

United Kingdom service

The Royal Navy did not adopt the gun, but several were adopted by the army as coast defence guns around the United Kingdom from 1900 onwards.^[1] In World War I the UK acquired 620 ^[3] of a version manufactured in Japan, and mounted them as anti-submarine guns on merchant ships and troop ships, under the designation Mark V*. Many of these guns were used again in World War II on defensively armed merchant ships and troop ships.

Notable actions

Main article: Action of 10 March 1917

On 10 March 1917 the crew of a single gun on the refrigerated cargo liner Otaki fought a notable action against the heavily armed German commerce raider SMS Möwe. They managed to set the Möwe on fire and inflicted significant damage before the Otaki was sunk. Otaki's Master Archibald Bisset Smith went down with his ship and was posthumously awarded the Victoria Cross for refusing to surrender his ship.

See also

• Type 3 120 mm 45 caliber naval gun version in service with the Imperial Japanese Navy from 1918
• QF 4.7 inch Gun Mk I – IV 40-calibre version adopted by the Royal Navy
• List of naval guns
• Brixham Battery World War II Emergency Coastal Defence Battery using this gun