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.
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
Armament: 8 x 5.3”, 12 x 65mm AA, 22 x
6-barrel 20mm AA
Complement: 1,420
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.
Design
and construction
Work on converting Roma into an aircraft
carrier began in earnest at Cantieri Ansaldo, Genoa, in November 1941. Since a
battleship named Roma was already under construction, the ship's name was
changed to Aquila.
Hull
The liner's interior was completely gutted
to allow for replacement of the original machinery and the addition of a hangar
deck and workshops. Deep bulges were added to either side of the hull to
improve stability and provide a modest degree of torpedo defense. A layer of
reinforced concrete—6–8 cm (2.4–3.1 in) thick—was applied inboard of the bulges
for splinter protection. The hull was also lengthened to take advantage of the
increased power of Aquila′s new machinery.
The designers worked in 3–8 cm (1.2–3.1 in)
of armor over the magazines and aviation fuel tanks. The fuel tanks copied
British practice and consisted of cylinders or coffer dams separated from the
ship's hull by water-filled compartments. This was a safety measure intended to
prevent fracturing of the fuel system and the inadvertent spread of volatile
AvGas fumes due to severe vibration or "whip" from bomb hits, near
misses and torpedo hits.
Machinery
Aquila′s new propulsion system consisted of
four sets of Belluzzo geared turbines taken from two canceled Capitani
Romani-class light cruisers (Cornelio Silla and Paolo Emilio). They were
capable of generating 151,000 shp (113,000 kW), and Aquila was expected to
reach 30 kn (56 km/h; 35 mph) on trials and 29.5 kn (54.6 km/h; 33.9 mph) when
fully laden.
Flight
deck
Aquila had a single continuous 211.6 × 25.2
m (694 ft 3 in × 82 ft 8 in) flight deck. It was partially armored with 7.6 cm
(3.0 in) plate over the gasoline bunkers and magazines. The flight deck ended
short of the bows but overhung the stern, where it featured a pronounced
round-down to improve air flow. Two 50 feet (15 m) octagonal lifts with a 5
short tons (4.5 t) capacity enabled transfer of aircraft between the hangar
deck and flight deck. One was directly amidships and the second another 90 ft
(27 m) forward, thus placing them far enough from the aft arrester wires that
both could be used for striking down aircraft into the hangar immediately after
a landing.
Two German-supplied Demag compressed
air-driven catapults, each capable of launching one aircraft every 30 seconds,
were installed parallel to each other at the forward end of the flight deck.
These were originally intended for Germany's own "Carrier B", Graf
Zeppelin′s incomplete—and eventually scrapped—sister ship. The Italians obtained
them—along with five sets of arrester gear and other component plans—during a
naval technical mission to Germany in October–November 1941.
A set of rails led aft from the catapults
to the elevators and into the hangars. For catapult-assisted launches, aircraft
would be hoisted in the hangar onto a portable collapsible catapult carriage,
raised on the elevators to flight deck level and then trundled forward on the
rails to the catapult starting positions, the same system as employed on Graf
Zeppelin.
According to Edward L. Barker, Aquila′s
engines and catapults were successfully tested in August 1943. However the
arresting gear installed on the carrier, consisting of four cables, failed to
work properly. This prevented aircraft, once launched, from landing back on
board. It was therefore proposed that aircraft taking off from Aquila would,
after performing their mission, fly back to the nearest land-based airfield or
simply ditch in the sea, a serious and embarrassing limitation on her
capabilities as a fleet carrier.
Aquila′s starboard-side island contained a
single large vertical funnel for carrying exhaust gases clear of the flight
deck. It also included a tall command tower and the fire control directors for
the 135 mm (5.3 in) guns.
Anti-aircraft
armament
Six 6-barrelled 20 mm (0.79 in)/65 caliber
(cal) anti-aircraft (AA) cannons were positioned just fore and aft on the
island. In addition, Aquila carried eight 135 mm (5.3 in)/45 cal guns taken
from one of the canceled Capitani Romani-class cruisers. Though not designed as
dual purpose weapons, these guns had an elevation of 45° and were therefore
capable of providing a useful barrage against attacking enemy aircraft (by
comparison, Italy's best heavy AA gun—the 90 mm (3.5 in)/50 cal—had an elevation
of 85°). It was intended to mount 12 newly-designed 65 mm (2.56 in) AA guns on
sponsons just below flight deck level (six on either side of the hull).
However, this gun—with an automatic feeder and 20 rpm rate of fire—never got
beyond prototype stage. An additional 16 six-barrelled 20 mm cannons—also
mounted below the flight deck—rounded out the ship's AA defense.
Aircraft
Throughout 1942 and 1943, trials were
conducted at Perugia and Guidonia—the Regia Aeronautica′s equivalent to the
German Luftwaffe′s test facility at Rechlin—to find aircraft suitable for
conversion to carrier use. The Italians selected the SAIMAN 200, Fiat G.50 bis
and Reggiane Re.2001 as potential candidates.
In March 1943, German engineers and
instructors with experience on Graf Zeppelin arrived to advise on aircraft
testing and to help train future carrier pilots culled from 160 Gruppo C.T. of
the Regia Aeronautica. They brought with them examples of a Junkers Ju 87C
Stuka dive bomber (a navalized version with folding wings, arrester hook and
catapult attachment points) and an Arado Ar 96B single-engine trainer. After
conducting comparative flight trials, the Italians eventually settled on the
Re.2001 as their standard carrier fighter/fighter-bomber and even the Germans
concluded it had better potential than their own counterpart, the Messerschmitt
Bf 109T. All flight testing—including simulated braked deck landings—was
land-based.
Aquila′s planned air complement was 51
non-folding Reggiane Re.2001 OR fighter-bombers: 41 stowed in the hangar deck
(including 15 suspended from the deck head) and 10 on the flight deck in a
permanent deck park. A folding-wing version of the Re.2001 was planned, which
would have increased the size of Aquila′s air group to 66 aircraft, but this
never materialized. Only 10 Re.2001s were fully converted for carrier use. They
were given tail hooks, RTG naval radio equipment and bomb racks for carrying
650 kg (1,400 lb) of bombs. They were also armed with two 12.7 mm (0.5 in)
Breda-SAFAT machine guns mounted above the engine cowling. At least one
Re.2001G was under test at Perugia as a naval torpedo bomber and was given a
lengthened tail wheel strut to accommodate the added height of a torpedo
suspended below the fuselage.
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. 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.
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