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Caio Duilio


Caio Duilio became a rare Italian battleship that saw service in both World Wars and survived into the Cold War period.
Authored By: Staff Writer | Edited: 7/10/2017
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Year: 1915
Ships-in-Class: 2
Named Ships: Andrea Doria; Caio Duilio
Complement: 2033
Length: 577 ft (175.87 m)
Width: 92 ft (28.04 m)
Height: 31 ft (9.45 m)
Displacement (Surface): 25,000 tons
Propulsion: 20 x Boilers feeding 4 x Parsons steam turbines developing 30,000 horsepower to 4 x Shafts.
Speed (Surface): 21 kts (24 mph)
Range: 4,779 nm (5,500 miles; 8,851 km)
Operators: Kingdom of Italy
The Dreadnought Battleship reigned supreme for a time in naval history, the era brought about by the introduction of HMS Dreadnought of the British Royal Navy in 1906. This vessel outshone all others of the period due to its use of an "all-big-gun" main armament arrangement coupled with a steam-based propulsion system. Such a revolution was the warship that all previous models worldwide were rendered obsolete and therefore classed as "Pre-Dreadnoughts".

Prior to the arrival of World War 1 in Europe, the Italian Navy began construction of two dreadnought warships under the Andrea Doria-class name - "Andrea Doria" as the lead ship and her sister "Caio Duilio". The group was scheduled to succeed the Conte di Cavour-class built from 1910 to 1915 and comprising three total warships. The Andrea Doria vessels themselves were built from 1912 to 1916 and entered service in 1915 (World War 1 began in 1914). Caio Duilio saw her keel laid down on February 24th, 1912 and launched on April 24th, 1913. She was completed on May 10th, 1915.

As built, Caio Duilio displaced 27,260 tons (short) and held a length of 577 feet, a beam of 92 feet and a draught of 31 feet. Her propulsion scheme centered on 20 x boilers feeding 4 x Parsons steam turbines developing 30,000 horsepower to 4 x shafts under stern. Speeds reached 21 knots in ideal conditions and range was out to 4,800 nautical miles when making headway at 10 knots. Aboard were 35 officers and 1,998 enlisted personnel.

Armament was the heart of any battleship of the period. Caio Duilio fielded 13 x 12" (305mm) guns as its primary battery, these held in five total turrets, two forward, two aft and one amidships. The furthest forward and aft turrets displayed three guns apiece with the inner pairing showcasing two guns. The center turret was given a three-gunned arrangement. There were 6" (152mm) guns spread about the ship to act as secondary armament, mainly surrounding the forward and aft superstructures.13 x 3" (76mm) guns were also carried for shorter-ranged work. Another 6 x 76mm guns were reserved for point defense against aircraft attacks and, as was customary for warships of the period, 3 x 450mm (18") torpedo tubes were installed.

Armor protection ranged from 10" at the belt to 11" at the primary gun turrets. The deck was protected in nearly 4" of armor and the conning tower carried 11" inches of armor plating.

With the outbreak of war, the Italian Navy would be called to protect Italian and Allied interests across the Mediterranean with a particular eye towards the Austro-Hungarian fleet. However, with the enemy fleet displaying little inclination to leave its protected port, Caio Duilio managed just four wartime patrols and no direct action in the whole of the war.

The warship's next notable service arrived with participation in the Russian Civil War (1917-1923). She sailed the Black Sea in support of the "White Russians" before returning to Taranto. Once there, she was placed in reserve and not reactivated until 1920. In late 1923, one of her No.3 turret magazines detonated forcing repairs at La Spezia and the work kept her laid up until April 1928. From March until June 1930, Caio Duilio was refitted and placed back in reserve during August 1932, made flagship of the Italian Reserve Fleet the following year. She later entered into a reconstruction effort to help modernize the design and this work lasted from March 1937 until July 1940.

World War 2 had befallen Europe and Caio Duilio would prove a critical component to Italian prowess in the Mediterranean. Her first war patrol was on August 31st, 1940 and several attempts to run down a British force failed so she took refuge at Taranto. Caio Duilio was present in the harbor on November 10th - 11t, 1940 when the British fleet launched their surprise attack (Battle of Taranto). She took a torpedo to her side but was saved when the vessel was pushed to shallower ground. She was floated in January 1941 and moved to Genoa for repairs. Genoa harbor then came under attack from the British but Caio Duilio survived unscathed. She reported back for service on May 16th, 1941 (Taranto).

Several convoy support sorties followed but shortages of marine fuel and oil led her to be placed in reserve during 1942. She lay in Taranto harbor until the Italian surrender of September 1943 and then was moved with the rest of the Italian fleet to Malta. She returned to Italian waters during June 1944 but managed no further impact on the war. Caio Duilio finished her career in service with the Italian Navy during the immediate post-war years. In 1953 she was retired and stricken from the Naval Register in September 1956. Stripped of her war-making usefulness, her hulk was scrapped in 1957.


13 x 12" (305mm) main guns
16 x 6" (152mm) secondary guns
13 x 3" (76mm) guns
6 x 76mm Anti-Aircraft (AA) guns
3 x 450mm (18") torpedo tubes

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