320 mm Model 1934 naval gun
From Wikipedia, the free encyclopedia
| Cannone navale da 320 | |
|---|---|
 This photo shows the typical fore-and-aft installation of a twin turret superfiring over a triple turret. | |
| Type | Naval gun |
| Place of origin | Italy |
| Service history | |
| In service | 1937 – 1956[1] |
| Used by |
|
| Wars | Second World War |
| Specifications | |
| Mass | 64 tonnes[2] |
| Barrel length | 14 meters (550 inches)[2] |
| Shell | 525 kilograms (1,160 lb)[2] |
| Caliber | 320 mm (12.6 in)[2] |
| Muzzle velocity | 830 meters per second (2,700 ft/sec)[2] |
| Maximum firing range | 30 kilometres (19 mi)[2] |
The 320 mm naval gun was the main battery gun used to modernize Italy's World War I battleships for service during World War II.[1] The guns were manufactured by boring out and relining the battleships' original 12"/46 (30 cm) built-up guns and modifying the turrets to increase elevation above the original 20° maximum. Each ship carried two 548-tonne twin turrets and two 745-tonne triple turrets. All guns used pneumatically operated side-swing Welin breech blocks. Each barrel could fire two rounds per minute.[2]
In service these guns chronically suffered of great horizontal dispersion, both from the worsened thermodynamic performance of the guns themselves and from the unequal quality of the shells fired.[3]
The Conte di Cavour-class battleships Conte di Cavour and Giulio Cesare originally mounted 13 guns as built in 1915 and 1914. These ships were rebuilt between 1933 and 1937 by removing the Q triple turret amidships and replacing guns in triple A turret, twin B and X turrets, and triple Y turret. Conte di Cavour carried Vickers Mk G guns while Giulio Cesare carried Pattern T guns built by Elswick Ordnance Company. Odero Terni Orlando (OTO) re-bored the Vickers guns while the Elswick guns were re-bored by Gio. Ansaldo & C. Maximum gun elevation was increased to 27°.[2]
M1936 guns
The Andrea Doria-class battleships Andrea Doria and Duilio originally mounted 13 guns as built in 1916 and 1915. These ships were similarly rebuilt between 1937 and 1940 by removing Q turret and replacing guns in A, B, X, and Y turrets. Pattern T guns aboard Duilio were similarly rebuilt by Ansaldo while Mk G guns aboard Andrea Doria were rebuilt by OTO. Maximum gun elevation was increased to 30°.[2]