The delivery of these weapons was greatly delayed, the average being over one year later than planned. For Cavour, this delay would have been even longer, but guns intended for Doria were used when her construction was delayed.
In the 1930s many of these guns were bored out to 32 cm (12.6") for the reconstructed Cesare and Duilio class battleships, but some were retained in their original caliber and used in coastal artillery batteries.
Mark "G" was a fully wire-wound type with inner A, A, B tubes, jacket and breech ring. Pattern "T" had an inner A tube, A tube in two parts joined by screwed collar, B tube and half-length wire, jacket and short breech ring. A pneumatically operated Welin breech block was used for both.
Battleship Dante Alighieri
|Designation||12"/46 (30.5 cm) Model 1909|
|Ship Class Used On||Dante Alighieri, Conte di Cavour and Caio Duilio Classes|
|Date Of Design||1909|
|Date In Service||1913|
|Gun Weight||62.5 tons (63.5 mt)|
|Gun Length oa||about 571 in (14.500 m)|
|Bore Length||552.0 in (14.021 m)|
|Rate Of Fire||2 rounds per minute|
|Projectile Types and Weights||APC - 997 lbs. (452 kg)|
|Muzzle Velocity||2,758 fps (840 mps)|
|Approximate Barrel Life||N/A|
|Ammunition stowage per gun
|Dante Alighieri: N/A
Conte di Cavour and Caio Duilio: 100 rounds
|Note: Normal outfit for Conte di Cavour and Caio Duilio was 40 rounds AP and 30 rounds HE fragmentation shells but there was space for 100 rounds.|
|Elevation||With 997 lbs. (452 kg) AP shell|
|Range @ 20 degrees||26,240 yards (24,000 m)|
Conte di Cavour (2) and Caio Duilio (2)
about 500 tons (508 mt)
|Elevation||-5 / +20 degrees|
(see Note 1)
|Conte di Cavour class
A and X turrets: +150 / -150 degrees
B and Y turrets: +155 / -155 degrees
Q turret: 360 degrees
Caio Duilio class
|Loading Angle||Any angle|
1) Please note that although Q turret on these ships could train a full 360 degrees, it could not fire directly forward or aft without striking the superstructure of the ship.
2) Ammunition supply was hydraulically powered while the elevation machinery was an electrical-hydraulic system.
02 May 2008 - Benchmark
26 May 2012 - Added mounting notes