The Conte di Cavour–class battleships were a group of three dreadnoughts built for the Royal Italian Navy (Regia Marina) in the 1910s. The ships were completed during World War I. In December 1915, and January 1916, when the Serbian army was driven by the German forces under General von Mackensen toward the Albanian coast, 138,000 Serbian infantry and 11,000 refugees were ferried across the Adriatic and landed in Italy in 87 trips by the and other ships of the Italian Navy under the command of Admiral Conz. These ships also carried 13,000 cavalrymen and 10,000 horses of the Serbian army to Corfu in 13 crossings from the Albanian port of Vallons. was sunk by a magazine explosion in 1916 and sold for scrap in 1923. The two surviving ships, and , supported operations during the Corfu Incident in 1923. They were extensively reconstructed between 1933 and 1937 with more powerful guns, additional armor and considerably more speed than before.

Both ships participated in the Battle of Calabria in July 1940, when Giulio Cesare was lightly damaged. They were both present when British torpedo bombers attacked the fleet at Taranto in November 1940, and Conte di Cavour was torpedoed. She was grounded with most of her hull underwater and her repairs were not completed before the Italian surrender in September 1943. Conte di Cavour was scrapped in 1946. Giulio Cesare escorted several convoys, and participated in the Battle of Cape Spartivento in late 1940 and the First Battle of Sirte in late 1941. She was designated as a training ship in early 1942, and escaped to Malta after Italy surrendered. The ship was transferred to the Soviet Union in 1949 and renamed Novorossiysk. The Soviets also used her for training until she was sunk when a mine exploded in 1955. She was scrapped in 1957.

Design and description

thumb|left|Original configuration

The Conte di Cavour–class ships were designed by Rear Admiral Engineer Edoardo Masdea, Chief Constructor of the Regia Marina, and were ordered in response to French plans to build the s. They were intended to be superior to the Courbets and to remedy 's perceived flaws of weak protection and armament. As upgrading a warship's protection and armament on a similar displacement typically requires a loss in speed, the ships were not designed to reach the of their predecessor. They were still given a advantage over the standard of most foreign dreadnoughts. Foreign dreadnoughts were being designed with guns, but the Regia Marina was forced to use guns in the Conte di Cavours because Italy lacked the ability to build larger guns. An additional gun, making a total of 13, was added to offset this deficiency.

Taking advantage of the lengthy building times of these ships, other countries were able to build dreadnoughts that were superior in protection and armament, with the exception of the French. They displaced at normal load, and at deep load. The Conte di Cavour class was provided with a complete double bottom and their hulls were subdivided by 23 longitudinal and transverse bulkheads. The ships had two rudders, both on the centerline. They had a crew of 31 officers and 969 enlisted men.

Propulsion

The original machinery for all three ships consisted of three Parsons steam turbine sets, arranged in three engine rooms. The center engine room housed one set of turbines that drove the two inner propeller shafts. It was flanked by compartments on either side, each housing one turbine set which powered the outer shafts. Steam for the turbines was provided by 20 Blechynden water-tube boilers in Conte di Cavour and Leonardo da Vinci, eight of which burned oil and twelve of which burned both oil and coal. Giulio Cesare used a dozen each oil-fired and mixed-firing Babcock & Wilcox boilers. Designed to reach a maximum speed of , none of the ships reached this goal on their sea trials, despite generally exceeding the rated power of their turbines. They only achieved speeds ranging from using . The ships could store a maximum of of coal and of fuel oil that gave them a range of at , and at .

Armament

As built, the ships' main armament comprised thirteen 46-caliber 305-millimeter guns, in five gun turrets. The turrets were all on the centerline, with a twin-gun turret superfiring over a triple-gun turret in fore and aft pairs, and a third triple turret amidships, designated 'A', 'B', 'Q', 'X', and 'Y' from bow to stern. This was only one fewer gun than the Brazilian Rio de Janeiro, then the most heavily armed battleship in the world; Rio de Janeiros guns were mounted in seven twin-gun turrets. The turrets had an elevation capability of −5° to +20 degrees and the ships could carry 100 rounds for each gun, although 70 was the normal load. Sources disagree regarding these guns' performance, but naval historian Giorgio Giorgerini claims that they fired armor-piercing (AP) projectiles at the rate of one round per minute and that they had a muzzle velocity of which gave a maximum range of . The turrets had hydraulic training and elevation, with an auxiliary electric system.

The secondary armament on the first two ships consisted of eighteen 50-caliber guns, also designed by Armstrong Whitworth and Vickers, mounted in casemates on the sides of the hull. These guns could depress to −10 degrees and had a maximum elevation of +15 degrees; they had a rate of fire of six shots per minute. They could fire a high-explosive projectile with a muzzle velocity of to a maximum distance of . The ships carried a total of 3,600 rounds for them. For defense against torpedo boats, the ships carried fourteen 50-caliber guns; thirteen of these could be mounted on the turret tops, but they could be mounted in 30 different positions, including some on the forecastle and upper decks. These guns had the same range of elevation as the secondary guns, and their rate of fire was higher at 10 rounds per minute. They fired a AP projectile with a muzzle velocity of to a maximum distance of . The ships were also fitted with three submerged torpedo tubes, one on each broadside and the third in the stern.

Armor

thumb|A Conte di Cavour-class battleship during [[World War I]]

The Conte di Cavour-class ships had a complete waterline armor belt that was high; of this was below the waterline and above. It had a maximum thickness of amidships, reducing to towards the stern and towards the bow. The lower edge of this belt was a uniform in thickness. Above the main belt was a strake of armor thick that extended up to the lower edge of the main deck. Above this strake was a thinner one, 130 millimeters thick, that extended from the bow to 'X' turret. The upper strake of armor protected the casemates and was thick. The ships had two armored decks: the main deck was thick in two layers on the flat that increased to on the slopes that connected it to the main belt. The second deck was thick, also in two layers. Fore and aft transverse bulkheads connected the armored belt to the decks.

The frontal armor of the gun turrets was in thickness with thick sides, and an roof and rear. deck that reduced to between the forecastle and upper decks and 130 millimeters below the upper deck. The forward conning tower had walls 280 millimeters thick; those of the aft conning tower were 180 millimeters thick. The total weight of the protective armor was ,

Modifications and reconstruction

thumb|right|upright=1.3|[[Office of Naval Intelligence drawing of the Conte di Cavour class, January 1943]]

Shortly after the end of World War I, the number of 50-caliber 76 mm guns was reduced to 13, all mounted on the turret tops, and six new 40-caliber 76-millimeter anti-aircraft (AA) guns were installed abreast the aft funnel. In addition two license-built 2-pounder AA guns were mounted on the forecastle deck abreast 'B' turret. In 1925–1926 the foremast was replaced by a tetrapodal mast, which was moved forward of the funnels, the rangefinders were upgraded, and the ships were equipped to handle a Macchi M.18 seaplane mounted on the center turret. Around that same time, one or both of the ships was equipped with a fixed aircraft catapult on the port side of the forecastle.

The sisters began an extensive reconstruction program directed by Vice Admiral (Generale del Genio navale) Francesco Rotundi in October 1933.

Only 40% of the original ship's structure remained after the reconstruction was completed.

Two of the propeller shafts were removed and the existing turbines were replaced by two Belluzzo geared steam turbines rated at . In service their maximum speed was about . The ships now carried of fuel oil which provided them with a range of at a speed of .

thumb|right|Giulio Cesare leading her sister after their reconstruction

The center turret and the torpedo tubes were removed and all of the existing secondary armament and AA guns were replaced by a dozen 120-millimeter guns in six twin-gun turrets The guns were bored out to 320 mm Model 1934 naval gun| and their turrets were modified to use electric power, a fixed loading angle of +12 degrees, and the guns could now elevate to +27 degrees. The 320 mm AP shells weighed and had a maximum range of with a muzzle velocity of . In 1940 the 13.2 mm machine guns were replaced by 65-caliber Breda Model 35| AA guns in twin mounts. Giulio Cesare received two more twin mounts as well as four additional 37 mm guns in twin mounts on the forecastle between the two turrets in 1941. Atop the conning tower there was a director fitted with two rangefinders, with a base length of .

Ships

{|class="wikitable plainrowheaders"

|+ Construction data

!scope="col"|Ship

!scope="col"|Namesake

!scope="col"|Builder

!scope="col"|Laid down

!scope="col"|Launched

|-

!scope="row"|

|Camillo Benso, Count of Cavour

|La Spezia Arsenale, La Spezia

|10 August 1910

|10 August 1911

|1 April 1915

|Sunk during the Battle of Taranto 12 November 1940; salvaged 1941; scrapped 1946

|-

!scope="row"|

|Julius Caesar

|Gio. Ansaldo & C., Genoa

|24 June 1910

|15 October 1911

|14 May 1914

|Transferred to the Soviet Union, 1949; sank 29 October 1955 after hitting a mine; salvaged and scrapped, 1957

|-

!scope="row"|

|Leonardo da Vinci

|Odero, Genoa-Sestri Ponente

|18 July 1910

|14 October 1911

|17 May 1914

|Sunk by magazine explosion, 2 August 1916; salvaged 1919; sold for scrap, 22 March 1923 killed.

Conte di Cavour escorted King Victor Emmanuel III and his wife aboard Dante Alighieri, on a state visit to Spain in 1924 and was placed in reserve upon her return until 1926, when she conveyed Mussolini on a voyage to Libya. The ship was again placed in reserve from 1927 until 1933. Her sister became a gunnery training ship in 1928, after having been in reserve since 1926. Conte di Cavour was reconstructed at the CRDA Trieste Yard while Giulio Cesare was rebuilt at Cantieri del Tirreno, Genoa between 1933 and 1937. Both ships participated in a naval review by Adolf Hitler in the Bay of Naples in May 1938 and covered the invasion of Albania in May 1939.

right|thumb|Conte di Cavour in Naples, 5 May 1938

Early in World War II, the sisters took part in the Battle of Calabria (also known as the Battle of Punta Stilo) on 9 July 1940, as part of the 1st Battle Squadron, commanded by Admiral Inigo Campioni, during which they engaged major elements of the British Mediterranean Fleet. The British were escorting a convoy from Malta to Alexandria, while the Italians had finished escorting another from Naples to Benghazi, Libya. Admiral Andrew Cunningham, commander of the Mediterranean Fleet, attempted to interpose his ships between the Italians and their base at Taranto. Crew on the fleets spotted each other in the middle of the afternoon and the Italian battleships opened fire at 15:53 at a range of nearly . The two leading British battleships, and , replied a minute later. Three minutes after she opened fire, shells from Giulio Cesare began to straddle Warspite which made a small turn and increased speed, to throw off the Italian ship's aim, at 16:00. At that same time, a shell from Warspite struck Giulio Cesare at a distance of about . The shell pierced the rear funnel and detonated inside it, blowing out a hole nearly across. Fragments started several fires and their smoke was drawn into the boiler rooms, forcing four boilers off-line as their operators could not breathe. This reduced the ship's speed to . Uncertain how severe the damage was, Campioni ordered his battleships to turn away in the face of superior British numbers and they successfully disengaged. Repairs to Giulio Cesare were completed by the end of August and both ships unsuccessfully attempted to intercept British convoys to Malta in August and September.

On the night of 11 November 1940, Conte di Cavour and Giulio Cesare were at anchor in Taranto harbor when they were attacked by 21 Fairey Swordfish torpedo bombers from the British aircraft carrier , along with several other warships. One torpedo exploded underneath 'B' turret at 23:15, and her captain requested tugboats to help ground the ship on a nearby sandbank. His admiral vetoed the request until it was too late and Conte di Cavour had to use a deeper, , sandbank at 04:30 on 12 November. In an effort to lighten the ship, her guns and parts of her superstructure were removed and Conte di Cavour was refloated on 9 June 1941. Temporary repairs to enable the ship to reach Trieste for permanent repairs took until 22 December. Her guns were operable by September 1942, but replacing her entire electrical system took longer and she was still under repair when Italy surrendered a year later. The Regia Marina made plans to replace her secondary and anti-aircraft weapons with a dozen dual-purpose guns in twin mounts, twelve 64-caliber , and twenty-three 65-caliber 20 mm AA guns.

thumb|left|Aerial view of Conte di Cavour after her reconstruction

Giulio Cesare participated in the Battle of Cape Spartivento on 27 November 1940, but never got close enough to any British ships to fire at them. The ship was damaged in January 1941 by a near miss during an air raid on Naples; repairs were completed in early February. She participated in the First Battle of Sirte on 17 December 1941, providing distant cover for a convoy bound for Libya, again never firing her main armament. In early 1942, Giulio Cesare was reduced to a training ship at Taranto and later Pola.

After the war, Giulio Cesare was allocated to the Soviet Union as war reparations in 1949, and renamed Novorossiysk, after the Soviet city on the Black Sea. The Soviets used her as a training ship when she was not undergoing one of her eight refits in their hands. In 1953, all remaining Italian light AA guns were replaced by eighteen 37 mm 70-K AA guns in six twin mounts and six singles. They also replaced her fire-control systems and added radars, although the exact changes are unknown. The Soviets intended to rearm her with their own 305 mm guns, but this was forestalled by her loss. While at anchor in Sevastopol on the night of 28/29 October 1955, she detonated a large German mine left over from World War II. The explosion blew a hole completely through the ship, making a hole in the forecastle forward of 'A' turret. The flooding could not be controlled and she later capsized with the loss of 608 men. Novorossiysk was stricken from the Navy List on 24 February 1956, salvaged on 4 May 1957, and subsequently scrapped.

Notes

Footnotes

References

Further reading

  • Cavour class – Plancia di Comando
  • Conte di Cavour Marina Militare website