Small fast boats with torpedos (or other explosives) have always been a threat to large warships. One of the weapons the British Royal Navy adopted to counter that threat was the Hotchkiss Model 1886 "Quick Fire" gun. This meant that it was a breech-loaded gun that used self-contained cartridge ammunition, instead of separate powder bags and projectiles. Mounted on a recoil-adsorbing soft mount with a wide range of movement and steep depression angle, guns like this could fire at small mobile torpedo boats that a capital ship's main armament couldn't handle.

This particular model is a 47mm bore, or 3-pounder as described in British service. It uses a vertically-traveling breech block, and more than 3,000 or them were acquired by the British. Two of them were employed as part of the Falkland Islands coastal defenses at one time. This example is one of two brought down from Gibraltar fairly recently and refurbished for ceremonial use on the Islands. Thanks to the FIDF for setting it up on its mount so I could film it for you!