Dante Alighieri

History

Design

Though not Italy’s first dreadnought design, Dante Alighieri was the first dreadnought battleship built for the Regia Marina. The concept of the ‘all big-gun battleship’ in Italy dated back to the early 1890s, mostly thanks to the work of the naval architect Vittorio Cuniberti, culminating in the 1903 ‘Colossus’ design, a 17,000-ton, 24-knots, twelve 12”-gunned battleship. Though proposed to the Regia Marina, it was rejected on fiscal grounds. With the Regia Marina’s permission, however, he was able to publish an article about it in Jane’s Fighting Ships of 1903, advocating it as the ideal type of battleship for the British Royal Navy.

Although the Regia Marina had rejected their first opportunity to enter, and in fact lead, the dreadnought race in 1903, by the latter half of the decade there was a much greater need for an increase in the strength of the fleet, due to increase in strength of the Austro-Hungarian K.u.k. Kriegsmarine from 1900 to 1909. Thus, Italy decided to procure their first dreadnought, with the design of the ship falling to General Edoardo Masdea, supported by General Giuseppe Rota (both where of the Naval Corps of Engineers, or Genio Navale, and whose rank structure differed from that of the regular navy).

Dante Alighieri reflected the principles favored by contemporary Italian battleship design as well as new ideas introduced by the colossus/dreadnought concept. As had generally been the case of Italian battleships since the time of the great ironclads of the Duilio-class, armor protection was sacrificed for the sake of speed, though protection still remained at the level of a battleship. In line with Italian ideas about dreadnought battleships, the ships were designed for maximum broadside firepower – twelve guns, made possible by the adoption of triple turrets. These were arranged entirely along the centerline of the ship at the height of the forecastle deck, a conscious choice which was intended to keep the ship’s center of gravity low, and so keep a low profile (which also led to the minimalist approach to the conning tower and funnels). In order to reach the designed top speed of 23 knots, the ship had a relatively long and narrow hull (158.4 x 26.6 meters at the water) with a L/B ratio of 5.95. The ship utilized twenty-three Blechynden water-tube boilers, of which sixteen were mix-fired and seven oil-fired, to power three turbine groups powering four shafts (the outer shafts had high pressure and low-pressure turbines, but the amidships shafts were separately run by a high pressure and a low-pressure turbine), which was intended to reach 35,000 shp. On trials on 9 June 1912, Dante Alighieri made 22.83 knots on 32,189 shp at a load of 21,140 tons, and on the 16th, made 23.825 knots at 35,378 shp with forcing on six-hour trials.

The main battery consisted of twelve Armstrong (Elswick) Pattern T 12” (305mm)/46, also known as the Modello A1909, mounted in four triple turrets. These fired 452 kg APC and 404.6 kg HE shells, with a muzzle velocity of 840 or 861 m/s, depending on the source. Thanks to having a maximum elevation of +20°, these had a maximum range of 21,500 meters or 24,000 meters, again depending on the source, with rate of fire ranging from 1.5 to 2 rounds per minute per gun, and ammunition stowage was 100 rpg (1,200 rounds). Upon entry into service, for fire control Barr & Stroud monostatic rangefinders of the F.Q. 2 type, with a 2.74-meter base length, were used, with one being installed on top of the conning tower and the aft atop the stern command tower, plus one in each of the main battery turrets. This allowed for an effective engagement range of 10,000 meters (11,000 yards).

The secondary battery consisted of twenty Armstrong (Elswick) Pattern EE 4.7” (120mm)/50, or Modello A1909. Eight guns were mounted in four twin turrets, one positioned on each ‘corner’ of the ship, while the remaining twelve were mounted in casemates (four sets of three) on the main deck, allowing each ‘quarter’ of the ship to be covered by five guns. These guns fired either 22.06 kg SAP or 23.15 kg HE shells at a velocity of 850 m/s, and could reach 12,000 meters with their elevation of +20°. Rate of fire is variably reported as 6-10 rpm, though 4 rpm was more typical in service. For the anti-torpedo boat role, thirteen Armstrong (Elswick) Pattern ZZ1 3” (76mm)/50, or Modello A1909, were carried, with variable mounting positions on the forecastle, at the stern, in the ships central portion, or up to three on any of the main battery guns. These guns fired 7 kg shells at 815 m/s with a range of about 11,000 meters and a rate of fire of 15 rpm.

Also carried were three 450mm torpedo tubes – two carried forward of the no.1 main battery turret, angled so that one could fire off either bow quarter, and another aft firing out of the stern.

Protection was modest, as was typical of Italian battleships of the era. Armor weight totaled 4,020 tons, some 18.6% of normal displacement (19,500 tons). The main armor belt was made of cemented plates 250mm thick (with the lower portion tapering to 170mm), covering the area from just forward of the no.1 main battery turret to the area just aft of the no.4 main battery turret, and extending to the stem with a thickness of 100mm and to the stern with a thickness of 76mm. The main transverse bulkheads where the 250mm portion of the belt terminated was 100mm forward and 76mm aft. The upper belt (protecting the space between the main deck and battery deck) was 203mm thick, while the casemate belt above that was 100mm thick. The upper deck was 24mm thick (12+12mm), the main deck 30mm (18+12mm), and the battery deck 24mm (12+12mm) amidships and 50mm thick (25+25mm) on the ‘turtleback’ slopes connecting to the bottom of the main armor deck. The main battery turrets had 250mm faces, 220mm sides, and roofs described as 76mm or 150mm thick depending on the source. Barbette armor was 240mm above and below the forecastle deck, terminating at the main deck. The small 120mm turrets had 100mm faces and 50mm roofs. The conning towers, fore and aft, are variably described as 305mm and 220mm or 280mm and 200mm, depending on the source.

The design was able to achieve most of the objectives intended for it, boasting a very powerful broadside (the highest of any Mediterranean dreadnoughts when first completed) and a high turn of speed, up to 23 knots. The design did have shortcomings, however, as the armor protection remained modest, and end-on fire was limited due to all guns being mounted on the same deck level. Sea spray often made it difficult to operate the forward 120mm guns in less than ideal sea conditions, and due Italian fire control falling behind that of the British and Germans in the second half of the 1900s, could not effectively engage to the maximum range of the guns even up to the start of WWI.

Over her service life, Dante Alighieri went through minor changes with one major refit from 1922 to 1923. In 1913, Curtiss seaplanes were trialed from the ship, but as arrangements were not satisfactory, abandoned. In 1915 her armament was augmented by the addition of additional 76/50 guns (four) in the anti-aircraft role. In 1916, the Regia Marina ordered British triplex rangefinders of the F.T. 25 types, with a 4.57-meter base length, but due to delays resulting in demand from Britain’s own navy, these were not installed until 1917, replacing the single rangefinder atop the conning tower forward. This raised effective engagement range to 16,460 meters (18,000 yards).

In a major refit from 1922 to 1923 a tripod foremast was installed over her conning tower, which came in step with the installation of a director control system as part of the Salvagnini fire control system. In February 1924, this system was trialed, at a range of 26,000 meters, and proved to be successful in concept even if the tripod mast proved to ‘whippy’ and caused the specific test to fail. This informed refits that followed on the rest of the class members. Also installed in this refit was a quartet of 40mm/39 Vickers-Terni AA guns, and an aircraft flying-off platform atop turret no.3 for a Macchi M.18 flying boat.

Service

Dante Alighieri was laid down at the Royal Yards at Castellammare di Stabia on 6 June 1909, immediately making a landmark for herself as the first warship laid down with three-gun turrets. She was launched on 20 August 1910 to much fanfare, after fourteen months on the slips, but had a long fitting-out period due to delays in armor plate production and the manufacturing of her main guns. As a result, she was only commissioned into the Regia Marina on 15 January 1913. The battleship took her name from the medieval poet Dante Alighieri, often considered to be a father to the Italian language and literary tradition. The ship’s motto was Con l’animo che vince ogni battaglia (‘with the soul that wins every battle’).

After further trials and work-up, she embarked on a long-range cruise into the Atlantic in March 1913, visiting various west African ports such as Dakar, Funchal, Ponta Delgada and Vigo, returning in April. Shortly after her return, she embarked the King (Vittorio Emanuele III) and other members of the Royal Family to observe the launch of the battleship Duilio on 24 April (also at Castellammare di Stabia). After this, the career of Dante Alighieri began in earnest, with intensive combat training primarily in the Tyrrhenian Sea. In May of 1914 she was assigned to the 1st Division of the 1st Fleet, alongside other active dreadnought battleships of the Regia Marina (Giulio Cesare and Leonardo da Vinci). As Italy declared neutrality upon the outbreak of WWI, the fleet was not immediately thrust into war, and thus still conducted primarily training activities. Ultimately, Italy would enter on 23 May 1915 on the side of the Entente, and thus the fleet remained at the ready at Taranto should the Austro-Hungarian fleet present the opportunity for battle. However, outside of an opening bombardment against Ancona on the day Italy entered the war, the Austrian Fleet remained firmly wedded to their anchorages at Pola, thus leaving the Italian battlefleet at Taranto, and their French counterparts at Corfu, with little to do. As a result, the fleet sortied largely only for training sorties, including a brief visit to Corfu from December 1916 through January 1917. Ultimately, it was not until September 1918 that Dante Alighieri was able to sortie on a proper war mission acting as cover for the bombardment of Durazzo.

As World War I came to an end, Dante Alighieri was moved up to Venice, arriving on 9 November 1918, to provide support, if necessary, for Italian forces occupying the Dalmatian coast. In February 1919 the went on a tour of various Dalmatian cities, and on the 25th, steamed into the former Imperial port of Pola, to escort surrendered Austro-Hungarian ships to Venice, before moving back to Fiume on 20 May, where she remained until 6 January 1921. In 1922 she moved to La Spezia and went into reserve where she underwent a major refit from late 1922 through 1923. She returned to service in the spring of 1924, and was once again used for diplomatic tasks, bringing the King to Valencia on his official visit to Spain. Further combat exercises and large-scale maneuvers followed for the summer of 1924 and 1925, and once again in 1927 after temporarily being placed in reserve in 1926. However, this was to be her last period of operation. On 1 July 1928 she was placed in reserve for the last time. The ship, like most of the Italian dreadnoughts, was obsolescent due to the rapid march in technology from when she had been laid down (1909). She was too slow to keep up with the modern cruisers, capable of over 30 knots, and had inadequate deck armor for long-range gunnery combat or to cope with modern bombs. Likewise, underwater protection was insufficient for dealing with modern torpedoes or mines. This, in company with her high operating costs (due to requiring 970 sailors and officers to man), put her on the chopping block. Thus, on 1 November 1928 Dante Alighieri was struck from the naval register, and subsequently scrapped. She had enjoyed a service life of just 15 years.

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  Right elevation and plan of Dante Alighieri from Brassey's Naval Annual 1923.

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  Dante Alighieri on 29 March 1914.

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  Dante Alighieri in Taranto.