RN Roma

In the 1930s, as the naval treaties that had limited battleship construction began to fray, Italy resolved to build a fleet of fast, modern capital ships worthy of its ambition to dominate the Mediterranean — the Mare Nostrum of Fascist rhetoric. The result was the Littorio class (also called the Vittorio Veneto class), among the finest battleships any nation produced and the pride of the Regia Marina.

Roma was the third ship of the class to be completed, laid down at the Cantieri Riuniti dell'Adriatico in Trieste and commissioned in June 1942. By the time she joined the fleet, however, the strategic situation that had justified her construction was already slipping away — fuel was desperately short, Allied air and naval power was rising, and the great surface battles the class had been designed to win were no longer being fought.

Roma was a genuinely modern and powerful design. Her main armament of nine 381mm (15-inch) guns in three triple turrets fired an exceptionally heavy, high-velocity shell, and she was protected by a sophisticated armour scheme and the distinctive Italian Pugliese system of underwater torpedo defence. Capable of around 30 knots, she combined the firepower of a battleship with the speed of a battlecruiser.

Her lines were widely admired — clean, balanced and purposeful — and in a straight fight she could hold her own against almost any contemporary. Yet the class shared the era's universal weakness: like every battleship of her generation, she had been conceived for a war of gun duels between fleets, and was poorly prepared for the new threat that would ultimately destroy her — the aircraft, and the guided weapon.

The Regia Marina's chronic fuel shortage compounded the problem. For much of her short career Roma swung at anchor or made only limited sorties, conserving the precious oil the Italian fleet never had in sufficient quantity, and she never once fired her great guns at an enemy warship.

On paper the 381 mm /50 Ansaldo-OTO Mod. 1934 outperformed every other 15-inch gun of the war. It threw an 884.8 kg armour-piercing shell at 850 m/s to beyond 42 km, and by the US Navy's penetration formula it would defeat 510 mm of vertical armour at 18,000 m — more than the belt of any battleship it could realistically meet. In practice the shells did not land where the arithmetic said they should. Salvos spread, and the spread grew worse the further the target lay: the defect was well known in the Regia Marina, and it is the reason a battery superb by every static measure produced so few hits.

The explanation given at the time, and repeated ever since, came from Admiral Angelo Iachino: Italian industry could not hold tolerances, and shells and charges varied enough in weight to scatter the fall of shot. Batch-to-batch variation in service ammunition was real — Littorio grouped tightly at 32,000 yards in one action while Vittorio Veneto shot badly at 24,000 in another — but the explanation does not survive the trials data. Dispersion just as wide was measured at the proving ground, where the guns fired matched al peso rounds selected for controlled weight and geometry, against charges weighed almost exactly. Whatever was scattering the salvos was still there when the tolerances were removed.

The study devoted to the question — Marco Santarini, in Warship International in 2020 — locates the fault in the flight of the shell rather than in its manufacture. The rifling was a uniform 1 in 30, the same twist the British used in their 15-inch, but it was driving a shell of comparable weight at 850 m/s against the British 752. The projectile therefore left the muzzle spinning faster than it needed to, over-stabilised: its axis stayed where it had been pointed instead of following the trajectory as that curved downward, and the growing angle between the two — yaw, with precession and nutation around it — dragged at the shell unevenly for the rest of its flight. Since the mismatch widens as the trajectory steepens, so does the scatter, which is exactly the behaviour the gunners reported. Muzzle velocity was later cut from 870 to 850 m/s to narrow it, and the same high velocity that caused the trouble also wore the barrels out: 110 to 130 rounds of effective life, against 335 for the British 15-inch.

Roma was one of three completed sisters. The name ship Littorio (later renamed Italia after the fall of Fascism) and Vittorio Veneto bore the brunt of the Regia Marina's surface war, fighting at engagements such as Cape Spartivento, the disastrous night action off Cape Matapan, and the convoy battles of the Sirte. A fourth ship, Impero, was never completed.

Together the class represented Italy's bid for a modern battle fleet — fast, well-armed and handsome ships that looked every inch the part. But hamstrung by fuel shortages, the lack of radar in the early war, and the absence of naval air power, the class never achieved the decisive results its designers had envisaged.

Roma served chiefly as a fleet flagship, and her active career was cut short before she could prove herself in a surface action. Her fate was sealed not in battle with another fleet, but by the Italian surrender. Following the armistice of 8 September 1943, the Italian fleet was ordered to sail from La Spezia to Malta to surrender to the Allies, denying the ships to the Germans.

On 9 September 1943, off the coast of Sardinia, the fleet was attacked by 11 Dornier Do 217 bombers of Kampfgeschwader 100, each carrying the Fritz X — a 1,362 kg radio-guided armour-piercing glide bomb, one of the world's first precision-guided weapons. One bomb struck Roma at about 15:45 and passed through the hull; a second penetrated near the forward magazines and detonated the No. 2 turret magazine. The catastrophic explosion blew the turret overboard, broke the ship in two, and she capsized and sank within minutes, taking with her 1,393 of her ~1,850 crew, including the fleet commander, Admiral Carlo Bergamini.

Roma thus earned a grim place in history: the first capital ship ever sunk by a guided weapon, destroyed not by enemy guns but by a new technology that announced, as starkly as anything in the war, the end of the battleship's long reign.

Her killer was the Dornier Do 217 and its radio-guided Fritz X — a weapon against which a battleship’s vast armour was almost irrelevant, since the bomb fell from beyond the reach of her guns and steered itself down onto her deck. In a single afternoon off Sardinia the future of naval warfare had arrived, and the long age of the big-gun capital ship had begun to end.

RN Roma was among the most beautiful and powerful battleships of her age — a fast, heavily armed ship that embodied the Regia Marina's ambition to rule the Mediterranean. Yet she never fired her main guns at an enemy ship, her career strangled by fuel shortages and the changing nature of war at sea.

She was destroyed on the way to surrender by a Fritz X guided bomb released from a Dornier Do 217 — the first capital ship in history sunk by a precision-guided weapon. The wreck, found on the seabed in 2012, is protected as a war grave.

• Roger Chesneau (ed.), Conway’s All the World’s Fighting Ships 1922–1946 (Conway Maritime Press).
• Aldo Fraccaroli, Italian Warships of World War II (Ian Allan).
• Erminio Bagnasco & Augusto de Toro, The Littorio Class: Italy’s Last and Largest Battleships (Seaforth).
• William H. Garzke & Robert O. Dulin, Battleships: Axis and Neutral Battleships in World War II (Naval Institute Press).
• Marco Santarini, “Gunfire Dispersion of Large Italian Naval Guns: The Strange Case of the 381/50 Ansaldo-OTO mod. 1934 Gun”, Warship International 57/4 (December 2020).