QF 3-pounder Hotchkiss

QF 3-pounder Hotchkiss
Typical Royal Navy deck mounting, 1915
Type	Naval gun Coast-defence gun
Place of origin	France
Service history
In service	1886 - 1950s
Used by	French Navy Royal Navy Regia Marina United States Navy Imperial Russian Navy
Wars	World War I World War II
Production history
Designed	1885
Manufacturer	Hotchkiss et Cie
No. built	2,950 (UK)
Specifications
Barrel length	74.06 inch (1.88 m) bore (40 cal)
Shell	Fixed QF. Shell 3.3 lb (1.5 kg), steel shell, common lyddite
Calibre	47-millimetre (1.850 in)
Breech	vertical sliding wedge
Elevation	Dependent on Mounting: Mk I, Mk I* +25° Mk V +70° Mk VI +60°
Rate of fire	30 / minute
Muzzle velocity	1,873 ft/s (571 m/s)
Maximum firing range	4,000 yards (3,657 m)

The QF 3-pounder Hotchkiss or in French use Canon Hotchkiss à tir rapide de 47 mm (47mm / L40) was a light 47-mm naval gun introduced in 1886 to defend against new small fast vessels such as torpedo boats, and later submarines. It was also used ashore as a coast defense gun and later occasionally as an anti-aircraft gun.

In 1886 this gun was the first of the modern QF artillery to be adopted by the Royal Navy as the "Ordnance QF 3 pounder Hotchkiss", built under licence by Elswick Ordnance Company.

By the middle of World War I the Hotchkiss gun had become obsolescent, and was gradually replaced in its class by the more powerful Ordnance QF 3 pounder Vickers gun. Of the 2,950 produced it is estimated that 1,948 were still available in 1939 for RN use. The gun's availability, simplicity and light weight resulted in its continued use in small vessels, and many were later brought back into service on merchant vessels used for auxiliary duties in World War II, or as saluting guns and sub-calibre guns for gunnery practice until the 1950s. Early in WWII it was also pressed into service in ports around the British Empire, to defend against possible incursions by motor torpedo boats until the modern QF 6 pounder 10 cwt gun became available in numbers for that purpose.

A 3-pounder Hotchkiss was used on an improvised mounting in a battle that resulted in Australia's first prisoners of World War 2 being captured in 1940 near Berbera.

The guns are now used in a Three Pound Saluting Gun Battery at the Garden Island Naval Base.

Russia adopted the Hotchkiss 5-barrel Gatling-type 3-pounder revolver cannon in the 1880s, and later adopted the less complicated single-barrel quick-firing weapon. The 5-barrel guns were equipped on the Ekaterina II-class battleships commissioned in 1889, but by 1892 the battleship Dvenadsat Apostolov and her successors had single-barrel weapons. 47 mm Hotchkiss guns were used during the Russo-Japanese war and were ineffective against Japanese torpedo boats, so they were removed from first-line warships following that war. New Russian battleships ceased carrying the weapon with the Evstafi class, commissioned in 1910. However, they were subsequently fitted to patrol vessels and river craft during World War I, and at least 62 weapons were converted to anti-aircraft guns by 1917.