The Ammiraglio di Saint Bon class was a pair of pre-dreadnought battleships built for the Italian Navy () during the 1890s. The class comprised two ships: , the lead ship, and . They were armed with a main battery of four guns and were capable of a top speed of . Smaller and less powerfully-armed than most contemporary battleships, they marked a brief departure from Italian capital ship design, which had previously emphasized large ships equipped with large guns.
Both ships served in the active duty squadron early in their careers, and participated in the Italo-Turkish War of 1911–1912. They took part in the Italian offensives in North Africa and the island of Rhodes, but did not see combat with the Ottoman fleet. They were reduced to harbor defense ships by the outbreak of World War I, and they spent the war in Venice. The ships were discarded shortly after the end of the war, both having been stricken in 1920.
Design
The previous Italian capital ships, the and the es of ironclad battleships, marked a period of experimentation on the part of Benedetto Brin, Admiral Simone di Pacoret Saint Bon, and the strategists of the Italian navy. Since the planners had not determined what type of battleship would best suit their strategic needs, the government stepped in and mandated a design, a limit significantly lower than the earlier classes. Following the death of di Saint Bon, Brin took over the design process and proposed a small battleship armed with guns, a weaker main battery than those of contemporary foreign designs.
The ships, much smaller than their contemporaries, and slower than cruisers, were not particularly useful warships. The mistake of building a battleship of only 10,000 tons was not repeated in the subsequent, and much more successful, .
General characteristics and machinery
The ships of the Ammiraglio di Saint Bon class were long at the waterline and long overall. They had a beam of and a maximum draft of . Ammiraglio di Saint Bon displaced at normal loading and at full load, while Emanuele Filiberto displaced and , respectively.
The ships had an inverted bow and a relatively low freeboard of only . They had a fairly large superstructure with a conning tower and high bridge forward and a large military mast fitted with fighting tops placed amidships. Abreast the mast, each ship carried a number of small boats. Ammiraglio di Saint Bon had a crew of 557 officers and enlisted men, while Emanuele Filiberto had a slightly larger complement of 565.
The ships' propulsion system consisted of two triple-expansion steam engines, which drove a pair of screw propellers. Steam for the engines was provided by twelve coal-fired cylindrical fire-tube boilers, which were ducted into a pair of widely spaced funnels. Ammiraglio di Saint Bons were rated at , while Emanuele Filibertos engines only reached . The ships' propulsion system provided a top speed of and a range of approximately at .
Armament and armor
The ships were armed with a main battery of four 40-caliber guns manufactured by Armstrong Whitworth. The guns were placed in two twin gun turrets, one forward and one aft. The ships were also equipped with a secondary battery of eight 40-cal. guns in individual casemates amidships. These guns were export derivatives of the British QF 6-inch /40 gun. Ammiraglio di Saint Bon was also equipped with eight 40-cal. guns in shielded pivot mounts directly above the casemate battery, while Ammiraglio di Saint Bon carried six guns. Close-range defense against torpedo boats was provided by a battery of eight guns and two guns. Emanuele Filiberto had eight guns instead. Both ships also carried four torpedo tubes in deck-mounted launchers.
The ships were protected with Harvey steel. The main belt was thick, and the deck was thick. The conning tower was protected by 249 mm of armor plating on the sides. The main battery guns also had 249 mm thick plating on the turrets, and the casemates were thick.
Ships of the class
Service
was built by the Venetian Arsenal in Venice. She was laid down on 18 July 1893, launched on 29 April 1897, and completed on 24 May 1901, although she had been commissioned on 1 February 1901. was named after Prince Emanuele Filiberto, Duke of Aosta. She was built by the (Royal Shipyard of Castellammare di Stabia), Naples. She was laid down on 5 October 1893, launched on 29 September 1897, and completed on 16 April 1902, although she had been commissioned on 6 September 1901. The ships spend the first several years in the active duty squadron until they were replaced by the new s, which entered service by 1908.