Giulio Cesare was one of three Conte di Cavour-class dreadnought battleships built for the Royal Italian Navy (Regia Marina) in the 1910s. Completed in 1914, she was rarely used and saw no combat during the First World War. The ship supported operations during the Corfu Incident in 1923 and spent much of the rest of the decade in reserve. She was rebuilt between 1933 and 1937 with more powerful guns, additional armor and considerably more speed than before.
During World War II, both Giulio Cesare and her sister ship, Conte di Cavour, participated in the Battle of Calabria in July 1940, when the former was lightly damaged. They were both present when British torpedo bombers attacked the fleet at Taranto in November 1940, but Giulio Cesare was not damaged. She escorted several convoys to North Africa 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 the Italian armistice the following year. The ship was transferred to the Soviet Union in 1949 and renamed Novorossiysk (Новороссийск). The Soviets also used her for training until she was sunk in 1955, with the loss of 617 men, by an explosion most likely caused by an old German mine. She was salvaged the following year and later scrapped.
The Conte di Cavour class was designed to counter the French Courbet-class dreadnoughts which caused them to be slower and more heavily armored than the first Italian dreadnought, Dante Alighieri. The ships were 168.9 metres (554 ft 2 in) long at the waterline and 176 metres (577 ft 5 in) overall. They had a beam of 28 metres (91 ft 10 in), and a draft of 9.3 meters (30 ft 6 in). The Conte di Cavour-class ships displaced 23,458 tonnes (23,088 long tons) at normal load, and 25,489 tonnes (25,086 long tons) at deep load. They had a crew of 31 officers and 969 enlisted men. The ships were powered by three sets of Parsons steam turbines, two sets driving the outer propeller shafts and one set the two inner shafts. Steam for the turbines was provided by 24 Babcock & Wilcox boilers, half of which burned fuel oil and the other half burning both oil and coal. Designed to reach a maximum speed of 22.5 knots (41.7 km/h; 25.9 mph) from 31,000 shaft horsepower (23,000 kW), Giulio Cesare failed to reach this goal on her sea trials, reaching only 21.56 knots (39.9 km/h; 24.8 mph) from 30,700 shp (22,900 kW). The ships carried enough coal and oil to give them a range of 4,800 nautical miles (8,900 km; 5,500 mi) at 10 knots (19 km/h; 12 mph).
The main battery of the Conte di Cavour class consisted of thirteen 305-millimetre Model 1909 guns, in five centerline gun turrets, with a twin-gun turret superfiring over a triple-gun turret in fore and aft pairs, and a third triple turret amidships. Their secondary armament consisted of eighteen 120-millimetre (4.7 in) guns mounted in casemates on the sides of the hull. For defense against torpedo boats, the ships carried fourteen 76.2-millimetre (3 in) guns; thirteen of these could be mounted on the turret tops, but they could be positioned in 30 different locations, including some on the forecastle and upper decks. They were also fitted with three submerged 450-millimetre (17.7 in) torpedo tubes, one on each broadside and the third in the stern.
The Conte di Cavour-class ships had a complete waterline armor belt that had a maximum thickness of 250 millimetres (9.8 in) amidships, which reduced to 130 millimetres (5.1 in) towards the stern and 80 millimetres (3.1 in) towards the bow. They had two armored decks: the main deck was 24 mm (0.94 in) thick on the flat that increased to 40 millimetres (1.6 in) on the slopes that connected it to the main belt. The second deck was 30 millimetres (1.2 in) thick. Frontal armor of the gun turrets was 280 millimetres (11 in) in thickness and the sides were 240 millimetres (9.4 in) thick. The armor protecting their barbettes ranged in thickness from 130 to 230 millimetres (5.1 to 9.1 in). The walls of the forward conning tower were 280 millimetres thick.
Modifications and reconstruction
Shortly after the end of World War I, the number of 76.2 mm guns was reduced to 13, all mounted on the turret tops, and six new 76.2-millimeter anti-aircraft (AA) guns were installed abreast the aft funnel. In addition two license-built 2-pounder (40 mm (1.6 in)) AA guns were mounted on the forecastle deck. In 1925–1926 the foremast was replaced by a four-legged (tetrapodal) mast, which was moved forward of the funnels, the rangefinders were upgraded, and the ship was equipped to handle a Macchi M.18 seaplane mounted on the amidships turret. Around the same time, either one or both of the ships was equipped with a fixed aircraft catapult on the port side of the forecastle.
Giulio Cesare began an extensive reconstruction in October 1933 at the Cantieri del Tirreno shipyard in Genoa that lasted until October 1937. A new bow section was grafted over the existing bow which increased her length by 10.31 metres (33 ft 10 in) to 186.4 metres (611 ft 7 in) and her beam increased to 28.6 metres (93 ft 10 in). The ship's draft at deep load increased to 10.42 metres (34 ft 2 in). All of the changes made increased her displacement to 26,560 tonnes (26,140 long tons) at standard load and 29,600 tonnes (29,100 long tons) at deep load. The ship's crew increased to 1,260 officers and enlisted men. Two of the propeller shafts were removed and the existing turbines were replaced by two Belluzzo geared steam turbines rated at 75,000 shp (56,000 kW). The boilers were replaced by eight Yarrow boilers. On her sea trials in December 1936, before her reconstruction was fully completed, Giulio Cesare reached a speed of 28.24 knots (52.30 km/h; 32.50 mph) from 93,430 shp (69,670 kW). In service her maximum speed was about 27 knots (50 km/h; 31 mph) and she had a range of 6,400 nautical miles (11,900 km; 7,400 mi) at a speed of 13 knots (24 km/h; 15 mph).
The main guns were bored out to 320 mm (12.6 in) and the center turret and the torpedo tubes were removed. All of the existing secondary armament and AA guns were replaced by a dozen 120 mm guns in six twin-gun turrets and eight 100 mm (4 in) AA guns in twin turrets. In addition the ship was fitted with a dozen Breda 37-millimetre (1.5 in) light AA guns in six twin-gun mounts and twelve 13.2-millimetre (0.52 in) Breda M31 anti-aircraft machine guns, also in twin mounts. In 1940 the 13.2 mm machine guns were replaced by 20 mm (0.79 in) 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. The tetrapodal mast was replaced with a new forward conning tower, protected with 260-millimetre (10.2 in) thick armor. Atop the conning tower there was a fire-control director fitted with two large stereo-rangefinders, with a base length of 7.2 metres (23.6 ft).
The deck armor was increased during the reconstruction to a total of 135 millimetres (5.3 in) over the engine and boiler rooms and 166 millimetres (6.5 in) over the magazines, although its distribution over three decks, meant that it was considerably less effective than a single plate of the same thickness. The armor protecting the barbettes was reinforced with 50-millimetre (2 in) plates. All this armor weighed a total of 3,279 tonnes (3,227 long tons). The existing underwater protection was replaced by the Pugliese torpedo defense system that consisted of a large cylinder surrounded by fuel oil or water that was intended to absorb the blast of a torpedo warhead. It lacked, however, enough depth to be fully effective against contemporary torpedoes. A major problem with the reconstruction was that the ship's increased draft meant that the waterline armor belt was almost completely submerged with any significant load.
Giulio Cesare, named after Julius Caesar, was laid down at the Gio. Ansaldo & C. shipyard in Genoa on 24 June 1910 and launched on 15 October 1911. She was completed on 14 May 1914 and served as a flagship in the southern Adriatic Sea during World War I. She saw no action, however, and spent little time at sea. Admiral Paolo Thaon di Revel, the Italian naval chief of staff, believed that Austro-Hungarian submarines and minelayers could operate too effectively in the narrow waters of the Adriatic. The threat from these underwater weapons to his capital ships was too serious for him to use the fleet in an active way. Instead, Revel decided to implement a blockade at the relatively safer southern end of the Adriatic with the battle fleet, while smaller vessels, such as the MAS torpedo boats, conducted raids on Austro-Hungarian ships and installations. Meanwhile, Revel's battleships would be preserved to confront the Austro-Hungarian battle fleet in the event that it sought a decisive engagement.