Russian 12 inch 40 caliber naval gun The 12 inch 40 caliber naval gun was the standard main weapon of the pre - dreadnought battleship s of the Imperial Russian Navy . Sixty - eight guns of the first production run were built in 1895 – 1906 by the Obukhov Works in Saint Petersburg . They were installed on seventeen battleships starting with " Sissoi Veliky " and " Tri Sviatitelia " and ending with the " Andrei Pervozvanny " class . A second production run was ordered to Russian and British gunmakers during World War I . History . In 1886 the Imperial Russian Navy adopted the 12 inch 35 caliber Krupp gun . The first batch of six German - made guns was installed on " Chesma " . Local production of the modified Krupp gun began in 1891 . Eleven Obukhov guns were installed on " Navarin " , " Chesma " and " Georgii Pobedonosets " . Low firing rate of these guns made them a temporary , intermediate weapon . In the same 1891 the Naval Technical Committee ordered the Obukhov Works to design a new gun with improved range and firing rate , employing smokeless powder . In May 1892 the Navy issued a firm contract for the guns and turrets of " Tri Sviatitelia " , followed by " Sissoi Veliky " and the " Petropavlovsk " class in May 1893 . Obukhov presented the first 12 inch 40 caliber gun for trials in March 1895 , thus the new gun was also unofficially called " Model 1895 " . Development of the 12 inch 40 caliber gun coincided with the beginning of the 1892 Franco - Russian Alliance . The Russian Navy abandoned German artillery models in favor of Canet and Schneider et Cie . designs , but the Krupp legacy persisted in the Navy ' s largest guns . The 12 inch 40 caliber became the Navy ' s standard main gun and was employed on all its pre - dreadnought battleship s starting with " Sissoi Veliky " of the Baltic Fleet and " Tri Sviatitelia " of the Black Sea Fleet . The seventeen battleships employing these guns had turrets of six distinct types . The earliest turrets of " Tri Sviatitelia " , " Sissoi Veliky " , " Pobeda " and " Petropavlovsk " were powered with hydraulic machinery and their firing rate was on par with the 12 inch 35 caliber guns mounted in electrified turrets . " Retvizan " became the first battleship with 12 inch 40 caliber guns in electrified turrets . Designers of the " Borodino " - class battleships increased firing rate to 90 seconds from shot to shot . The range of all these guns was limited by their modest vertical firing angle of 15° . " Potemkin " , designed to fight the Turkish defenses in The Straits , had its firing angle increased to 35° but required four minutes from shot to shot . The two " Andrei Pervozvanny " - class battleship s , built in 1904 – 1911 , were the last ships to receive the 12 inch 40 caliber guns ( in 1907 the Navy adopted the long - range 12 inch 52 caliber guns designed for the " Gangut " - class dreadnought s ) . The turrets of " Andrei Pervozvanny " allowed firing two broadsides per minute and allowed firing angles of up to 35° . The Navy planned to install similar turrets on the obsolete " Chesma " but the conversion was canceled . In the beginning of World War I the Imperial Navy ordered a second production run of the 12 inch 40 caliber model to replace the worn - out guns of the surviving pre - dreadnoughts . By the end of 1916 thirty new guns , produced at Obukhov Works and in England , were stockpiled in Saint Petersburg , Kronstadt and Sevastopol . The planned refit of the old battleships was interrupted by the 1917 Revolution . In the 1930s these guns were installed in coastal defence batteries and on TM - 2 - 12 railway gun platforms serving in the Far East . See also . Ships armed with the 12 inch 40 caliber guns : Equivalent guns of other countries :