Isa Frazione-Class Battleship

Class overview
Name:	Isa Frazione-Class Battleship
Builders:	Royal Shipbuilders of Cacerta
Operators:	Cacertian Royal Navy
Preceded by:	Dana Baldini-Class
Succeeded by:	Amika Carpio-Class Eloisa Moretti-Class
In commission:	1919 – 1947
Planned:	10
Completed:	10
Retired:	10
Preserved:	2
General characteristics
Type:	Battleship
Displacement:	35,768 tons standard 42,282 tons fully loaded
Length:	252.5 meters
Beam:	33 meters
Draft:	10.2 meters
Propulsion:	4 × shafts 4 × CNRC geared turbines 6 × pressure-fired boilers
Speed:	30 knots (56 km/h)
Range:	9,850 nautical miles at 15 knots
Complement:	1,376 Officers and Crew
Armament:	Guns: 8 × 380mm RN-MBI guns (2 × 4) 9 × 150mm RN-SBI guns (3 × 3) Dual-purpose: 24 × 100mm RN-DPIII guns (12 × 2) Anti-aircraft: 28 × 40mm RN-AAIV guns (14 × 2)

The Isa Frazione-class was a class of steam-powered battleship of the Cacertian Royal Navy designed and built following the Divide War. They were the first class of Cacertian warship that was not built to adhere to the static maneuvers of a line of battle as well as the first battleship class that mounted quadruple-gun turrets. Her primary armament consisted of eight of the newly re-designated 380mm RN-MBI naval guns.

The ships of the Isa Frazione-class first saw combat during the Divide War in which many of the ships saw combat. They were the one the main Cacertian battleship during the Siduri War and, although they were officially succeeded by the Eloisa Moretti-class, they would not be replaced until the 1940s with the introduction of the newer and more advanced Andrea Doria-class battleships.

Of the 10 ships in the class, only two remain. Both ships are preserved at the Fumicino Naval Warfare Museum.

Design

The Grand Admiralty of the Cacertian Royal Navy envisioned producing battleships with 380mm guns by 1920. The higher gun caliber promised better range and higher kinetic energy than the weapons of its dreadnought predecessors. The weapon's manufacturer, the CNRC, set about to the creation of the new naval gun which would be designed over the course of several years with a prototype delivered in early 1915. As a result of the development and adoption of the newer 380mm RN-MBI, several capital ships on the drawing board became obsolete and were immediately scrapped.

Following the initial Cacertian defeats during the Divide War, naval strategists and analysts—mainly from the Fumicino Naval Academy—concluded that newer vessels needed to fulfill a minimum speed of 28 knots to avoid being outrun by lighter naval vessels such as those fielded by Syara. The final design presented by Eugenia Davion and Eliana Marrazzo put the new class of warship at a standard weight of 35,000 tons making it the first warship to exceed a standard weight of 30,000. Nicknamed Prototype 35 during its development, it was an unconventional design in that it combined the roles of the primary and secondary armaments. The Prototype 35s would be armed with eight of the new 380mm cannons in conjunction with nine 150mm autoloading secondaries.

A number of new technological advances were to be used in the construction of the Prototype 35s, the most unique being the new autoloading technologies that would vastly increase the rate of fire on the ship’s 130mm stern-mounted cannons.

Armament

The Ministry of Defense specified in 1915 that the minimum loadout of future Cacertian warships needed to consist of eight guns at a minimum caliber of 380mm. It was determined that eight guns was considered most efficient for spotting salvoes and the new aggressive design of the Prototype 35s made them viable for pursuing enemy warships. Designers Eugenia Davion and Eliana Marazzo decided on an arrangement of two quadruple turrets to both save on more than a quarter of turret armor weight as well as place all of the vessel’s heaviest weaponry fore of the superstructure.

The most obvious drawback to the use of quad turrets was the possibility that a single penetrating hit could disable one turret and thereby render half of the primary battery out of commission. To counteract this, Eugenia divided the turrets internally with 40mm bulkheads in order to localize possible damage. At the Battle of the Sabri Sea during the Siduri War, the design proved effective when the Isotta Cusato suffered a penetrating hit on its second turret. The crew in the turret’s left side were killed and its two port guns were disabled, however rotation was unaffected and the other half of the turret remained intact.

The secondary battery would consist of six to nine 150mm cannons mounted on the ships’ stern, acting primarily as pursuit deterrents for smaller class enemy vessels as well as supplementary anti-aircraft weapons. Autoloaders had recently been developed by the CNRC and military commanders were very eager to put the new technology to use. The reliability and rapid-firing capabilities of the new autoloaders would ensure its future use on nearly every vessel long after the retirement of the Isa Frazione and her sister ships.

The class was also designed to possess a significant tertiary armament as part of the recent development of aircraft carriers and their growing usage throughout the world. To counter enemy planes, the Isa Frazione-class of warships were armed with twenty-four 100mm rapid-firing dual-purpose cannons mounted in dual turrets supplemented by twenty-eight smaller, but equally effective 40mm guns.

Propulsion

The Isa Frazione-class of warships utilized six CNRC pressure-fired boilers that powered four geared turbines. The boilers were part of a new type that forced circulation and allowed them to produce power well in excess of standard conventional boilers. The ships’ beam allowed the boilers to be installed parallel to one another with three on each side of the beam and allowing for the construction of two boilers rooms. The ship had two engine rooms with two sets of turbines, each powering a single four-bladed propeller shaft. At full power, the ships could travel at a speed of 30 knots.

Current Status

The last Isa Frazione-class battleship was decommissioned in 1948. By then, all units had been effectively replaced by the Andrea Doria-class of battleships and were eventually scrapped. Two ships remain preserved at the Fumicino Naval Warfare Museum.

Units

#	Designation	Name	Shipyard	Laid down	Launched	Commissioned	Status	Commanding Officer
I	BB-IF-001	Isa Frazione	Fumicino Dock 0044	11 February 1915	20 March 1917	30 May 1917	Preserved at the Fumicino Naval Warfare Museum.	N/A
II	BB-IF-002	Romolo Marcello
III	BB-IF-003	Angelo Ciliberto
IV	BB-IF-004	Luana D’Apice
V	BB-IF-005	Francesca Saccone
VI	BB-IF-006	Orfeo Tramontano
VII	BB-IF-007	Carmen Moise
VIII	BB-IF-008	Isotta Cusato	Fumicino Dock 0018	05 March 1916	12 April 1918	03 June 1918	Preserved at the Fumicino Naval Warfare Museum	N/A
IX	BB-IF-009	Desdemona Di Tommaso
X	BB-IF-010	Daria Troise