The Littorio class, also known as the Vittorio Veneto class,Vittorio Veneto and Littorio were laid down on the same date, so ambiguity exists in the naming of the class. was a class of battleship of the Regia Marina, the Italian navy. The class was composed of four ships—, , , and —but only the first three ships of the class were completed. Built between 1934 and 1942, they were the most modern battleships used by Italy during World War II. They were developed in response to the French s, and were armed with guns and had a top speed of . The class's design was considered by the Spanish Navy, but the outbreak of World War II interrupted construction plans.
The first two ships, Littorio and Vittorio Veneto, were operational by the early months of Italy's participation in World War II. They formed the backbone of the Italian fleet, and conducted several sorties into the Mediterranean to intercept British convoys, though without any notable success. The two ships were repeatedly torpedoed throughout their careers: Littorio was hit by a torpedo during the attack on Taranto in November 1940 and again in June 1942; Vittorio Veneto was torpedoed during the Battle of Cape Matapan in March 1941 and while escorting a convoy to North Africa in September 1941. Roma joined the fleet in June 1942, although all three ships remained inactive in La Spezia until June 1943, when all three were damaged in a series of Allied air attacks on the harbor.
In September 1943, Italy capitulated and signed an Armistice with the Allies. Littorio was then renamed Italia. The three active battleships were transferred to Malta before they were to be interned in Alexandria. While en route to Malta, German bombers attacked the fleet with Fritz X radio-guided bombs, damaging Italia and sinking Roma. Nevertheless, Italia and Vittorio Veneto reached Malta and were interned. The incomplete Impero was seized by the Germans after Italy withdrew from the war and used as a target, until she was sunk by American bombers in 1945. Italia and Vittorio Veneto were awarded to the United States and Britain, respectively, as war prizes. Italia, Vittorio Veneto, and Impero were broken up for scrap between 1952 and 1954.
Design The Washington Naval Treaty of 1922 allotted Italy an additional of total capital ship tonnage, which could be used in 1927–1929, while other powers were observing the "holiday" in battleship construction prescribed by the treaty. France, which was given parity with Italy, also possessed 70,000 tons of capital ship tonnage. Both countries were put under significant pressure from the other signatories to use their allotted tonnage to build smaller battleships with reduced caliber main batteries. The first Italian design, prepared in 1928, called for a ship armed with a main battery of six guns in twin turrets. They opted for this design because this allowed three ships under the 70,000-ton limit. This would have allowed the Italian fleet to keep at least two units operational at any given time. Protection and radius of action were sacrificed for speed and heavy armament, though the Italians did not value range, as they operated primarily in the confined waters of the Mediterranean.
Later in 1928, the design staff prepared another ship, with a displacement of , armed with six guns and protected against guns of the same caliber. At least one of these ships would have followed the three 23,000-ton ships once the building holiday expired in 1931. Funding was not allocated to begin construction, however, as the Italian Navy did not want to instigate an arms race with the French Navy. The London Naval Treaty of 1930 extended the building holiday to 1936, though Italy and France retained the right to build 70,000 tons of new capital ships. Both countries rejected British proposals to limit new battleship designs to and guns. After 1930, the Italian Navy abandoned the smaller designs altogether. By 1930, Germany had begun to build the three ships, armed with six guns, and France had in turn laid down two s to counter them. The French vessels were armed with eight guns. In late 1932, Italian constructors responded with a design similar to the Deutschland class, but armed with six guns in triple turrets on a displacement.
The Italian Navy decided that the smaller design was impractical, and that a larger design should be pursued. A design was then prepared, which mounted eight 343 mm guns in twin turrets. This was ultimately abandoned in favor of a 35,000 ton design to be armed with 406 mm guns. The 406 mm gun in turn was abandoned in favor of the 381 mm gun because there were no designs for the larger gun, which would delay construction; a 381 mm gun had already been designed for the canceled . Ultimately, nine 381 mm guns in three triple turrets were adopted as the primary battery for the ships, on a displacement in excess of , despite the fact that this violated the established naval treaties. Nevertheless, by the time these ships entered service, the international arms control system had fallen apart and the major naval powers had invoked the "escalator clause" that allowed for ships up to displacement.
General characteristics
The ships of the class varied slightly in dimensions. Littorio and Vittorio Veneto were long between perpendiculars and long overall, while Roma and Impero were long overall. All four ships had a draft of and a beam of . Littorio displaced as designed and at full load. Vittorio Veneto displaced and , respectively. Romas displacement increased slightly as compared to the other ships, to and , respectively. As Impero was not completed, her final displacement is unknown. As built, the ships were fitted with bulbous bows to increase their speed, but they were found to cause serious vibration, which forced a modification to the bow.
Littorio and Vittorio Veneto had a standard crew of 80 officers and 1,750 enlisted men; while serving as a flagship, the crew was increased by a command staff of between 11 and 31 additional officers. The standard crew for Roma and Impero was increased by 100 enlisted men. Aircraft facilities were located on the quarterdeck, where it was initially planned to base six La Cierva autogyros. Instead, a single catapult was fitted. The ships were equipped with three Ro.43 reconnaissance seaplanes or navalized Re.2000 fighters. The Re.2000 fighter was a wheeled aircraft and had to land on an airfield.
The ships' propulsion system consisted of four Belluzzo geared steam turbines powered by eight oil-fired Yarrow boilers. The engines were rated at and a top speed of . On sea trials, both Littorio and Vittorio Veneto exceeded the design specifications for their power plant. Littorio reached and , while Vittorio Veneto made and , both at light loadings. In service, however, the ships averaged . Figures for Romas speed trials have not been recorded. The ships carried of fuel oil, which enabled a maximum range of at a cruising speed of . At , the ships' range increased slightly to . The entire machinery system accounted for about 5.6 percent of the total displacement.
Armament
The ships' main battery consisted of nine 381 mm L/50 Ansaldo 1934 guns in three triple turrets, two in a superfiring pair forward and one aft. These long-barrel, high-velocity guns were chosen to compensate for the smaller 381 mm shell as compared to the 406 mm gun originally desired. The 381 mm guns had a maximum elevation of 35 degrees, which allowed them to engage targets out to . The guns fired a armor-piercing (AP) shell at a muzzle velocity of . However, this was reduced to in order to reduce dispersion and increase barrel service life. The semi-armor piercing shells formed the secondary ammunition of the 381mm/50, which had a bursting charge. Although high explosive shells weighing were developed for the 381 mm guns, they never saw service on the Littorio-class. Shell rooms were located below the propellant magazines beneath the gun house in the turret structure. The guns' rate of fire was one shot every 45 seconds. Their ammunition load was 495 AP shells and 171 SAP shells, with 4,320 propellant charges (666 rounds total, or 74 rounds per gun split 55 AP & 19 SAP).
The ships' secondary battery consisted of twelve L/55 Ansaldo Model 1934 guns in four triple turrets. Two were placed abreast the No. 2 main battery turret and two on either side of the rear turret. These guns fired a AP shell at a muzzle velocity of . They could elevate to 45 degrees, permitting a maximum range of . They had a rate of fire of slightly better than four rounds a minute. Four L/40 guns were mounted on each ship in order to fire illumination rounds. Able to elevate to 32 degrees, they fired a semi-fixed round out to an effective range of .
The ships' anti-aircraft armament was composed of a powerful battery of twelve 90 mm (3.5 in) L/50 guns closely arranged amidships, twenty L/54 guns, and sixteen L/65 guns. The 90 mm guns provided long-range anti-aircraft protection, and were mounted in quadriaxially stabilized single turrets. They had a rate of fire of 12 rounds per minute and had a ceiling of approximately . The 37 mm and 20 mm guns were designed for close-range defense and had effective ranges of and , respectively.
Armor
The main belt armor of this class was designed and tested to resist 381 mm armor-piercing shells at ranges down to , which was considered the inner edge of optimal combat range. The belt consists of a homogeneous armor outer plate and the cemented armor belt placed behind the outer plate; the 250 mm gap was filed with a cement foam called "Cellulite" to keep the water out of the gap and assist in de-capping armor piercing shells. The main armor belt was mounted on of oak timber and steel backing plate, and the entire belt structure was inclined at 11-15º, depending on the section of the hull. A homogeneous armor plate was placed behind the belt, followed behind by another plate sloped 26º in the opposite direction. The main citadel was closed off by forward and aft traverse bulkheads. The hull space above the citadel was an armored casemate with plating. The bow was protected by a belt that extends ahead of the main belt before terminating in a transverse bulkhead. The propeller shafts, aft diesel generator groups, and steering gear were protected by homogeneous armor plating and a separate bulkhead aft of the citadel.
The weather deck over the citadel consists of homogeneous armor over plating; the main armor deck varied depending on the space it was protecting. Over the magazines, the main armor deck was homogeneous armor laminated on a deck plating inboard and on 12 mm plating outboard. Over the machinery spaces, the main armor deck was on 12 mm plating inboard and on 12 mm plating outboard. The main armor deck extends to the bow and stern, where it thinned to over plating and over plating respectively.
The main battery turrets were protected by cemented armor faces, forward sides and roof, rear sides, rear roof, and rear. The barbettes were above the upper deck and below deck. The 152-mm secondary battery turrets were protected by faces, sides, rear, and roof, while their barbettes were above deck and below deck. Below the third deck, neither the primary nor secondary barbettes were protected by armor. The 90-mm heavy anti-aircraft mounts were protected by shield and barbette plating.
The conning tower was in the same style as the others designed by General Pugliese. The uppermost level was protected by on the front and sides and rear, all mounted on plating. The lower two levels had and respectively, all mounted on plating. The roof on 10-mm plating. An internal armored tube protected important electrical cables and pipes for hydraulic systems.
Pugliese torpedo defense system