The Caio Duilio was an Italian ironclad battleship launched in 1876; she was armed with the biggest cannons ever installed in a warship,
the 100-ton 450-millimeter muzzle-loading cannons. This made this ship and her twin the most powerful warships of that time; in comparison,
the British battleships of the Devastation class had been armed with 35-ton 305-millimeter cannons. The two turrets were installed
in the central part of the hull, not aligned to centerline but placed on each band in what is called an "echelon" arrangement, a disposition
adopted as well in the two subsequent classes of Italian battleships (take for example the Andrea Doria).
The first project for these ironclad provided 38-ton 317-millimeter cannons, but the British manufacturer offered to build 51-ton 381-millimeter
cannons and the Italians accepted. Great Britain quickly replied to this by building the HMS Inflexible, with a displacement of 11880 tonnes,
armor of up to 609 millimeters and four 80-ton 406-millimeters cannons. In turn Italy contested by ordering for the Caio Duilio the huge 100-ton
450-millimeter cannons. Because of the weight of these weapons and the thickness of the armor the length of the armored belt had to be restricted
as much as possible, hence the central disposition of the armament in these ships, measure which also helped to improve stability.
In the decade of 1880-90 were introduced heavy breech-loading cannons. It had been verified the higher effectiveness of projectiles with higher
muzzle speed, which was achieved with the utilization of "slow powders" and much longer cannons, in which muzzle loading would be non viable. This
brought as well the adoption of a new type of artillery mounting: the barbette. In these the cannon tubes would be
left without protection and only when the pieces were reloaded the breech would descend to the "turret". The Caio Duilio would never be
upgraded with these advances, but she received upgrades to her armament in the form of a secondary battery to face
the emerging threat of torpedo boats.
But those were times of very quick progress and since 1902 the Caio Duilio was relegated to the role of training ship, until in 1909 she was removed
from the naval register and disarmed to be reconverted into a coal and oil storage hulk, being her ultimate fate unknown.
Class: Caio Duilio (2 units - Caio Duilio, Enrico Dandolo)
Length: 109.2 meters
Beam: 19.7 meters
Draught: 8.3 meters
Displacement (normal): 11138 tonnes
Propulsion: 2 x shaft, 2 x vertical double-expansion steam engine, 8 x rectangular boiler, 7711 horsepower
Speed: 15 knots (27.8 kilometers/hour)
Range: 3760 nautical miles (6960 kilometers) at 10 knots
Armament (as built): 4 x 450-millimeter 20.5-caliber rifled muzzle-loading cannon, 3 x 356-millimeter torpedo tube
Armament (in 1890): 4 x 450-millimeter 20.5-caliber rifled muzzle-loading cannon, 3 x 120-millimeter 40-caliber cannon,
3 x 356-millimeter torpedo tube
Armament (in 1900): 4 x 450-millimeter 20.5-caliber rifled muzzle-loading cannon, 3 x 120-millimeter 40-caliber cannon,
2 x 75-millimeter cannon, 8 x 57-millimeter 40-caliber quick-firing cannon, 22 x 37-millimeter 20-caliber revolver cannon, 3 x 356-millimeter torpedo tube
Armor: 550 millimeters in belt, 30-50 millimeters in deck, 400 millimeters in citadel, 450 millimeters in barbettes,
250 millimeters in main turrets, 350 millimeters in conning tower