The Regia Marina (Royal Italian Navy) explored various projects for adding one or more aircraft carriers to the fleet in the 1930s but took no action beyond developing a basic design for constructing a new vessel and identifying suitable candidate merchant ships for conversion. In mid-1940, as Italy prepared to enter the war as an ally of Germany, a design was prepared for a simple conversion of the fast liner Roma into an aircraft carrier, but again was deemed less of a priority than other construction and set aside in January 1941.
It took the shock of defeat at Cape Matapan (March 28, 1941), which the Italians largely attributed to effective British deployment of its carrier Formidable, to revive demands for a carrier as an urgent requirement. In July 1941 the Undersecretary of the Navy authorized the conversion of the Roma into a carrier, using the design studies of the previous year as a basis. In the event, the project became much more ambitious and required a major transformation of the relatively elderly liner into the carrier Aquila.
Initially, the Regia Marina planned the Aquila (“Eagle”), as the new carrier was to be called, as bare-bones, minimum-effort conversion that would get aircraft to sea in minimal time. However, unanticipated minor problems and the navy’s understandable desire for the maximum possible capability in what might prove its only aircraft carrier led to a spiralling of new features, greater complexity, and mounting delays. To improve the hydrodynamics of the hull, increase fuel capacity, and provide the underwater protection naturally lacking in a merchant hull, large bulges were installed on either side of the hull at the waterline. The interior of the ship was completely gutted to make room for a large hanger with space for 40 airplanes, aviation stores, workshops, and accommodation for a crew of 1165 naval personnel and 243 pilots and support personnel from the Regia Aeronautica. A full-length flight deck topped the hanger, with a large island on a sponson to starboard. For protection against surface threats, the ship received eight 135-mm (5.3-in) L45 guns in single mounts along either side of the deck. Antiaircraft defense was supplied by twelve 65-mm L64 guns in single mounts along the deck edges and 132 x 20-mm L65 Breda machine guns in 22 sextuple mounts along the deck edges and fore and aft of the island. A small amount of armor—some in the form of concrete—was distributed around vital areas of the ship. On the whole, a well thought out, state of the art carrier thus emerged from all of this effort, but, as we shall see, at a fatal cost in time.
Displacement: 23,350 tons (standard), 27,800 tons (full load)
Dimensions: 759’2″ (oa) x 96’6″ x 24’0″
Flight deck: 700’0″ x 83’0″
Machinery: Belluzzo geared turbines, 8 Thornycroft boilers, 4 shafts, 140,000 shp = 30 knots
Bunkerage: 2,800 tons = 4,000 nm @ 18 knots
Aircraft: 36; some sources say Aquila’s air group would have been fifty-one Re2001’s, some of which were to be modified to carry a torpedo.
Armament: 8 x 5.3″, 12 x 65mm AA, 22 x 6-barrel 20mm AA
The superstructure was razed completely and a large hangar 525 feet long and 59 feet wide was erected beneath the steel flight deck. The Roma’s original power plant was replaced completely with two sets of machinery originally intended for light cruisers of the Capitani Romani class, raising the carrier’s speed from 21 knots to 30 knots. The furnace uptakes were trunked to starboard into a very large stack that was incorporated into a substantial island structure. Two elevators connected the hangar and flight deck, which carried two catapults and full arresting gear. All armament was fitted on platforms sponsoned out from the ship’s side. Magazines and aviation fuel stowage were created and protected by 3-inch armor decks. To ensure stability and provide effective defense against torpedo attack, the hull was fitted with deep bulges on each side.
When Italy surrendered on September 8, 1943, the Aquila was virtually complete. The Germans seized the ship but it was heavily damaged by United States Army Air Force bombing on June 16, 1944 and a human torpedo attack on April 19, 1945. On April 24, 1945, the ship was scuttled at Genoa. After World War II the ship was raised and taken to La Spezia in 1949. Initially the Italian Navy considered refitting the Aquila for service as a carrier but this plan was abandoned and the ship broken up in 1952. In late 1942 the Regia Marina decided to add a second carrier to the fleet and began a simple conversion of the liner Augustus along the lines originally proposed for the Roma.
Slow progress on the extensive Aquila conversion and the obvious need for additional carriers led the navy to revive the idea of an austere, minimum-change liner conversion in 1942. The liner Augustus was selected for conversion as the Sparviero (“Kestrel”). It was designed to be, essentially, a large escort carrier. Sparviero was to have a continuous flight deck surmounting a simple, hull-top hanger, but no island. Torpedo bulges were fitted to the hull, but no other major modifications were considered. The air group was to be limited to 20 aircraft. Gun armament would consist of six 152-mm (6-in) single-purpose guns and four 102-mm (4-in) antiaircraft guns. With a waterline length of 664 ft (202 m), a beam of 83 ft (25 m), a draft of 30 ft (9 m), she was roughly the same size as Aquila. But her original, tired diesel machinery would give only a fraction of the earlier carrier’s power—28,000 hp on 4 shafts—and a maximum speed of only 18 knots.
When the ship, by then renamed the Sparviero, was seized by Germany after Italy surrendered only the superstructure had been razed. The hulk was scuttled on April 24, 1945, in an attempt to block the entrance to the harbor at Genoa. It was raised in 1947 and scrapped.
The air groups for these carriers were particularly well-conceived. Rather than developing the plethora of limited-production, specialist types that typified the opposing Royal Navy Fleet Air Arm, the Regia Aeronautica standardized on a single type and adapted it to fulfill all the roles required of a naval strike aircraft. This would simplify the provision of spares and the training of naval pilots. It would maximize the number of aircraft that could be accommodated (51, including the deck park), and it would give the air group unparalleled flexibility. For strikes against enemy naval units, all aircraft could carry antiship ordnance, because each of the strike aircraft was capable of defending itself against combat air patrols. At the same time, in the event of an attack on the Aquila, all available aircraft could be used as fighters. There were no clumsy dive bombers or torpedo planes to be cleared from the deck in such a crisis.
For this one, multirole aircraft, the navy settled on the Reggiane Re.2001, the higher-performance, inline-engined version of the familiar Re.2000. The Re.2001 closely resembled the Re.2000 in almost all respects. But the bulky, trouble-prone Piaggio P.IX radial engine gave way to a liquid-cooled, Alfa Romeo RA.1000 RC.41a Monsone V-12, a license-built Daimler-Benz DB 601 offering 1175 hp for takeoff. At same time, the the Re.2000’s wing structure was redesigned to replace the leak- and fire-prone integral wing fuel tanks with more conventional armored fuel tanks, supplemented, when required, by a large torpedo-shaped drop tank under the fuselage. The Falco’s twin, nose-mounted, 12.7-mm Breda-SAFAT machine guns were supplemented by a 7.7-mm gun in each wing. Maximum speed increased to 339 mph (545 kmh) at 17,946 ft (5470 m) and range, on internal fuel, was 684 mi (1100 km).
Difficulties with license production of the DB 601 engine limited initial orders for the Re.2001 to only 120 aircraft. But, of these, fully 50 were Re.2001OR (Organizzazione Roma) models, specifically intended for the carrier project. The Re.2000OR incorporated strengthened landing gear and airframe components to cater to the higher loads anticipated during shipboard landings. A large, A-frame arrestor hook was fitted to the reinforced rear fuselage, and the airframe was finished in the elegant, overall pale grey-blue first seen on the Re.2000 catapult fighters. The naval aircraft retained the bomb shackle standard on land-based Re.2000 fighter bombers and could thus handle the naval bomber role. Weapons would probably have included a standard 551-lb (250 kg) demolition bomb and a special, 1389-lb (630-kg) armor-piercing antiship bomb.
While the Re.2001OR was admirably suited to the naval fighter and bomber roles, it could not fulfil the vital torpedo carrying mission as built. While bombs might cripple a ship, the torpedo was still the only weapon that could reliably strike below the waterline and sink ships. Accordingly Reggiane modified one of the Re.2001ORs (MM.9921) to carry a light torpedo as the Re.2001G. This was ready for flight tests in June of 1943, but crashed before torpedo trials could begin.