French 100 mm naval gun Modern French 100 mm naval guns are multipurpose artillery pieces ( anti - air , anti - ship , ground ) , capable of a high rate of fire . Most modern French warships are equipped with one of its versions . History . At the end of the Second World War , the French Navy was equipped with numerous calibres , most of which were due for decommissioning . In 1953 , the STCAN of Paris , under engineer Tonnelé , drafted the design of a polyvalent 100 mm gun . The gun was designed to be effective for The first turret of the family , " modèle 53 " , was tested at sea on the escort " Le Brestois " in 1958 and the escort aviso " Victor Schoelcher " in 1961 . Description . The most common version , " modèle 68 " , features a completely automatic action and control . The ammunition is stored in a magazine underneath the turret , and fed to the gun by a lift regularly manned by two crewmen . A flexible pipe allows feeding the gun under any orientation . Rounds of ammunition are fed automatically ; empty shell is ejected through an evacuation door on the front of the turret after firing . Cooling is provided by water circulating in layers of steel around the tube of the gun , and by an injection of air and water after every shot . The turret can be used in three modes : In manual mode , two crewmen serve the turret : the gunner , at the left of the gun , uses a joystick to point the gun , and optic ranging and aiming instruments to direct the fire ; the observer monitors the operations from the back of the turret . Aiming is performed by two electric motors , one for the elevation ( left of the turret ) and the other for the traverse ( right of the turret ) . Two hydraulic systems feed the gun . The gun can also be moved manually for maintenance . Since it is usually installed on the bow deck of warships , these turrets are often exposed to breaking waves and humidity . To prevent corrosion and mechanical problems , the turret is made water - tight by rubber joints . The gun itself is sealed by a rubber tampion , which can be shot through in case of emergency . The plexiglas viewbay used to manually aim the gun is usually protected by a steel cover . Versions . Over the years , the 100 mm turret went through several improvements , notably bringing more reliable operation and increased firing rate , new ammunition optimized to shoot down missiles , and compatibility with modern firing computers . Three main versions of French 100mm guns can be cited : Usage . The 100 mm gun has been used in the French navy on most warships equal or greater than aviso s ( the A69 especially , built and exported in 20 units ) . The " Charles de Gaulle " , with her MBDA Aster - only defence , is the main exception . Also , the future Horizon CNGF frigates should be equipped with the 76 mm Oto - Breda gun . It is not yet known whether this is a general tendency to abandon the 100 mm gun , or only a special case for certain specialized vessels . The 100 mm has been sold abroad , and is used by the navies of Argentina , Belgium , China , Portugal , Turkey , Brazil , Saudi Arabia , Bulgaria & Germany ( Mounted on " Köln " class frigates and " Hamburg " class destroyers . Both classes were already retired ) , and others . Belgian Wielingen class frigate s using the gun were sold to Bulgaria in 2004 - 2008 .