RN Aquila

Italy entered the war in June 1940 without a carrier, and not by oversight. The Regia Marina’s staff and Mussolini had both concluded that the country did not need one: a peninsula running down the middle of the Mediterranean, with airfields in Sicily, Sardinia, Puglia, Libya and the Dodecanese, was itself a flight deck. Mussolini called it the unsinkable aircraft carrier, and on a map the argument is not stupid.

It failed on a point the map does not show. Land airfields do not move with the fleet, and the aircraft on them belonged to the Regia Aeronautica, a separate service with its own priorities, its own targets and no naval training. A battle fleet at sea needed aircraft overhead within minutes; what it had was a request passed to another ministry, and reconnaissance that arrived when it arrived.

Two nights and one morning ended the argument. On 11–12 November 1940 Fleet Air Arm Swordfish flying from HMS Illustrious crippled three Italian battleships at their moorings in Taranto, from a carrier the Regia Marina had no equivalent of. Four months later, on 27–29 March 1941, the fleet was caught off Cape Matapan without air cover and lost three heavy cruisers and two destroyers in a night action it never saw coming.

After Taranto, Mussolini demanded that a liner be converted into a full fleet carrier rather than the light ship the navy had sanctioned in 1940. The navy’s technical staff raised objections and the work did not begin until July 1941 — eight months after the raid that made the case, and a year after the country had gone to war.

The hull carried a name the Regia Marina used twice over. The Roma the fleet knew was the battleship sunk by a guided bomb on 9 September 1943; this one was a transatlantic liner of 32,853 gross tons, launched by Ansaldo at Sestri Ponente on 26 February 1926 and belonging to an entirely different world. Stripped to the hull and rebuilt at Genoa from July 1941, she was to become Aquila, the Eagle.

The conversion followed the German Graf Zeppelin as its reference design, and it was thorough rather than improvised: new bulges for stability and torpedo protection, a completely new superstructure with an island to starboard, and a flight deck 213.5 m long and 25 m wide on a ship of 231.5 m overall. The finished displacement was to be 23,900 tonnes standard and 28,300 full — smaller than a British fleet carrier and considerably larger than an escort carrier.

A liner’s machinery moves 20 knots reliably for a week; a fleet carrier has to keep station with battleships. Aquila was therefore re-engined outright, and the engines came from ships that were themselves never finished: four sets of Belluzzo geared turbines taken from the cancelled Capitani Romani-class cruisers Cornelio Silla and Paolo Emilio, feeding four shafts from eight Thornycroft boilers arranged in four separate compartments.

The installed power was 151,000 shp, for a designed 30 knots on trials and 29.5 fully laden — fleet speed, and faster than most escort carriers of the period managed. The arrangement has a closing irony in it: the hull of the Cornelio Silla, robbed of her turbines to make a carrier, was herself seized incomplete at Genoa in September 1943 and sunk by Allied bombing in July 1944.

The surface battery was eight 135 mm /45 guns in single shielded mounts, and it came from the same programme as the turbines. The OTO/Ansaldo 135/45 of 1937–38 fired a 32.7 kg shell with separate ammunition; it was the secondary armament of the rebuilt battleships Andrea Doria and Caio Duilio, and the main armament of the Capitani Romani cruisers, which carried it in four twin mounts. Aquila took the same gun in singles, as did the rearmed Premuda and Spalato and the Comandanti Medaglie d’Oro destroyers.

What matters is what the battery was for. Eight 135 mm along the hull is a defence against destroyers and light cruisers — an anti-surface weapon on a ship whose real enemy would arrive from above. The entire anti-aircraft defence of the carrier was therefore delegated to the two lighter calibres, and one of them did not exist.

Twelve 65 mm /64 guns were to be carried on sponsons just below flight-deck level, six a side. The Model 1939 was an Ansaldo and Terni design and it was the only entirely new naval gun the Regia Marina started during the war: an automatic-feed medium-calibre weapon firing at 20 rounds a minute, exactly the class of gun — between the heavy battery and the light — that every navy discovered it needed and that Italy did not have.

It never got past the prototypes. The electric loading gear, with dual trays and a pantograph rammer, gave persistent trouble and the rammer was abandoned in favour of slower hand loading, which removed most of the point of the design. The programme was cancelled in the summer of 1943, before the armistice stopped work on the ship. Aquila’s medium anti-aircraft armament was cancelled while she was still being built to receive it.

That left the light guns, and there were a great many of them: 132 Breda 20 mm /65 barrels in 22 sextuple mounts, ranged along both deck edges and grouped fore and aft of the island. Six-barrel 20 mm mountings were unusual anywhere, and no other Italian warship was to carry anything like this weight of close-range fire.

It was a reasonable answer to the wrong question. The 20 mm Breda was accurate and reliable and it killed aircraft that had already committed to their attack — it could not break up a torpedo run or a dive before release, which is what the missing 65 mm was for. Aquila would have gone to sea with the heaviest light-AA battery in the Regia Marina and a hole where her medium battery should have been.

A liner’s hull has no armour and cannot be given much without ruining its stability, so the protection was improvised and it is the most unusual thing about the ship. Deep bulges were built along both sides for stability and a modest torpedo defence, and the inner compartments of those bulges were filled with concrete in a layer some 600 mm thick. Inboard of them ran a further 6–8 cm of reinforced concrete against splinters.

Steel was reserved for the two things that would destroy the ship if hit. Between 3 and 8 cm of armour covered the magazines and the aviation-fuel tanks, and the flight deck was armoured over those spaces alone, with 7.6 cm plate above the petrol bunkers and the magazines — nothing like the HMS Illustrious pattern of an armoured box, but protection where the fire would start. The avgas itself followed British practice: the tanks were cylinders and cofferdams isolated from the hull by water-filled compartments, so that the whip of a near miss could not fracture the system and fill the ship with petrol vapour.

The aircraft was to be the Reggiane Re.2001 in a navalised form, fitted with catapult spools and an arrester hook — an existing fighter adapted, because Italy had no purpose-built naval aircraft and no time to design one. Published figures for the air group vary because they measure different things: 36 is the figure usually quoted, 51 was the number planned for 1943, and up to 66 of the folding-wing Re.2001G would have fitted the same hangar volume.

None of the numbers were ever tested, because no aircraft embarked and none ever landed on. Italy had no carrier pilots, no deck-landing school and no arrester-gear experience, and the first Italian naval aviator would have had to learn on a ship that was still in the builders’ hands. The navalised Re.2001 flew from land as a prototype, and the ship it had been adapted for never took one aboard.

By the summer of 1943 Aquila was close. She was around 90 per cent complete — some references put it at 80, the difference turning on whether fitting-out and the uninstalled gun battery are counted — and she had passed her first static test, with the machinery in and the flight deck laid. What remained was fitting out, trials, and the training of an air group that did not yet exist.

The armistice of 8 September 1943 stopped everything. German forces took the ship where she lay in Genoa and placed her under guard, and work never resumed — not because the Kriegsmarine did not want a carrier, but because the yard was inside a war zone, the port was being bombed, and Germany had already failed to finish the Graf Zeppelin on which the design had been based.

There was a second ship. In 1942 the Regia Marina decided to convert Roma’s sister, the liner Augustus, on the same principle, as the Sparviero — the Sparrowhawk. Work began in November 1942.

She was the cheaper conversion and the less ambitious ship, and she got nowhere near as far: the armistice caught her barely begun, and she was never completed either. Between them the two hulls represent Italy’s entire carrier programme, and both had been passenger liners.

The ship’s only operational moment came at the very end, and it was directed against her. On 16 June 1944 she had already been damaged in an Allied air raid on Genoa. By April 1945 the concern was different: a 28,000-tonne hull sunk across the harbour entrance would have closed the port of Genoa to Allied shipping for months.

On the night of 18–19 April 1945 divers of Mariassalto — the unit formed from Decima Flottiglia MAS men who had gone with the co-belligerent government in the south — entered the harbour and partly sank her where she lay, in a position where she blocked nothing. The men who had trained to sink British ships at Alexandria and Gibraltar spent their last operation sinking an Italian one to keep a port open.

She was refloated in 1946 and towed to La Spezia in 1949, where completing her or converting her to some other use was considered and rejected. She was broken up in 1952, twenty-six years after she had been launched as a liner and eleven after the work began that was to make her a warship.

Aquila is the only aircraft carrier Italy built in the Second World War and she never sailed as one. The Regia Marina fought the whole Mediterranean war — Taranto, Matapan, the convoy battles, Pedestal — with land-based air support belonging to another service, and the decision to build a carrier was taken in November 1940, eight months after the war it was meant for had begun.

• Erminio Bagnasco & Achille Rastelli, Le navi da guerra italiane 1940–1945 (Albertelli).
• Aldo Fraccaroli, Italian Warships of World War II (Ian Allan).
• Robert O. Dulin & William H. Garzke, Battleships: Axis and Neutral Battleships in World War II (Naval Institute Press) — for the Regia Marina context.
• Marc’Antonio Bragadin, The Italian Navy in World War II (US Naval Institute) — the participant account of the carrier question.