TM-3-12 Railway Artillery Mount

The TM-3-12 is a heavy railway artillery mount carrying a 304.8 mm naval gun. Only three such mounts were built: the project began in 1935, and production in Nikolaev was completed on 1 January 1939. In firing position the mount weighs 340 tonnes, its crew numbers 50, and the gun can fire in any direction, traversing through 360°.

The barrels for the mounts were originally taken from the battleship Imperatritsa Mariya, lost at Sevastopol in 1916. During the Soviet–Finnish War the battery shelled Vyborg, and from September 1940 it was stationed on the Hanko Peninsula. In December 1941, before the garrison was evacuated, the mounts were disabled. In 1942–1943 a Finnish repair team partially restored them, using guns of the same type from the battleship Imperator Aleksandr III. After the armistice of 1944 the mounts were returned to the USSR, and until 1961 they served with the separate railway battery No. 294 at Baltiysk.

The 15.85-metre barrel rests on a massive body carried by multi-axle railway bogies with red wheels, and a lattice boom rises above the rear. According to the catalogue, the structure is made of metal and wood.