Railroad 500mm gun
Railroad 356mm gun
Railroad 305mm gun
12"/52 (30.5 cm) Pattern 1907
305 mm/52 (12") Pattern 1907
These were the most powerful guns ever used on a completed Russian or Soviet warship. They were built to a Russian design and many were also used as coastal artillery and railway guns.
The design of the gun began in 1906 at the Obukhov factory and a prototype was completed in 1907. The Navy initially ordered twenty guns from Obukhov at the end of 1907, with 178 more being ordered in the following years. 126 of these were delivered prior to 1917 (some sources say 144 guns). In 1917-18 an additional 42 guns were delivered, but after that point the Russian Civil War halted production until 1921 when 14 more guns were finished. In 1922 there were 29 guns at the factory at different stages of completion, some of which were subsequently finished. In 1939-40 some guns were converted into a loose liner type.
In the early part of World War II, France decided to transfer the 12 guns to Finland and Norway and three cargo ships were dispatched from Tunis to those nations. The two ships bound for Finland arrived safely and their eight guns were used for coastal batteries and railroad guns. But the Norwegian steamship Nina with her cargo of four guns was captured by the Germans in 1940 during the fighting in Norway. The Germans moved these guns back south and installed them as part of their Atlantic Wall defenses at Le Frie Baton, Guernsey Island, where they were known as Battery Nina (later renamed Battery Mirus after Kapitän zur See Rolf Mirus, killed in November 1941 near Guernsey Island). This battery was active between late 1942 and 1945 and survived the war, with the guns being scrapped sometime later. These guns appeared to have been modified to use standard German 30.5 cm (12") projectiles and propellants. One of the sources below reports that these guns were derated after reliability problems with these projectiles, but this may be a confusion between the much longer range for the "lightweight" Spr.gr. L/3,6 Bdz u. Kz (mhb) of about 56,000 yards (51 km) when compared to that for the "normal weight" Psgr. L/4,9 (mhb) of about 43,000 yards (39 km).
In addition to the Naval version of the gun, there was also a Coast Defense version which differed in having a larger chamber volume and used different ammunition, although it could also fire the naval rounds. By 1927 all of the coast defense guns had been changed over to using only naval ammunition. These were mainly mounted in twin coastal defense turrets that were designed in 1913. A total of 14 of these coastal defense turrets were built. Single open mountings were also produced for the coastal defense fortresses. There were four four-gun batteries around the Baltic, two four-gun batteries around the Black Sea and two five-gun batteries in the Far East. After the battleship Poltava was damaged by fire in 1924, her turrets were removed and then installed as coast defense batteries, two near Vladivostok in the 1930s and two near Sevastopol in the 1950s. Both batteries were in active service until 1996 and the turrets still survive.
Nomenclature note: This weapon is usually referred to as "Model 1910-1914" in western sources.
Constructed of A tube, two B tubes to the muzzle, two C tubes, two D tubes and jacket. The breech bush screwed into the jacket, locking the parts together, and a collar was shrunk on the breech bush and the end of the collar covered by a small ring with a shoulder. Both collar and ring were placed in position when hot. A Welin breech block was used.
The actual bore diameter was 304.8 mm (12.0").