HMS Illustrious (87): The Armoured Carrier That Refused to Sink

The First Armoured Carrier

HMS Illustrious was ordered on 13 April 1937 and built by Vickers-Armstrongs at Barrow-in-Furness, laid down just two weeks later, launched on 5 April 1939 and commissioned on 16 April 1940, at a cost of £2,295,000 excluding armament.

She was the lead ship of a revolutionary class of aircraft carrier, fitted with an armoured flight deck and hangar sides, three inches of protection over the deck and four and a half inches around the hangar, a design philosophy that traded aircraft capacity, she could carry only around 36 planes initially, later increased to 57, for a degree of survivability no other nation's carriers of the era could match.

She was also, rather less famously, the first aircraft carrier in the world built with an armoured hangar, and the first Royal Navy carrier fitted with radar before she had even completed, technological firsts that arguably mattered every bit as much as her armour when it came to fighting a modern naval war.

The armoured deck deserves an honest paragraph, because it has been argued about for eighty years and the answer is not the simple one. The decision was taken in 1936, and the reasoning was specific to where the Royal Navy expected to fight. British carriers were going to operate in the North Sea and the Mediterranean, within easy reach of land-based bombers, and in 1936 there was no way to see an air raid coming: radar was a laboratory curiosity, nobody knew whether it could be made small enough to put in a ship, and the technique of directing fighters onto a plot by radio did not exist. If you cannot intercept the bomber, the only remaining option is to survive the bomb. So the designers put three inches of armour over the hangar and four on its sides, and accepted the consequence, which was severe: the armour had to sit low enough to be structurally sensible, which meant a single hangar of restricted height, which meant far fewer aircraft. An American Essex off Okinawa in 1945 carried ninety to a hundred aeroplanes. A British armoured carrier carried forty-five to fifty. The counter-argument, made forcefully ever since, is that more fighters would have been better protection than more armour, and in the Pacific that is probably right. In the Mediterranean in 1941 it was emphatically wrong, and Illustrious is the proof.

Crippling the Italian Fleet at Taranto

HMS Illustrious deployed to the Mediterranean in August 1940 under Rear Admiral Lumley Lyster, and on the night of 11 to 12 November that year launched 21 Swordfish biplanes in two waves against the Italian battle fleet anchored at Taranto, a particularly audacious night attack against a heavily defended harbour.

The raid was a spectacular success: it rendered the battleship Conte di Cavour unavailable for the remainder of the war and badly damaged the Littorio and the Duilio, in a single stroke crippling half of Italy's battleship strength and demonstrating, more than a year before Pearl Harbor, exactly what a determined carrier strike against a fleet at anchor could achieve.

Taranto is worth the detail, because the whole thing was improbable. Twenty-one Swordfish, open-cockpit biplanes with a top speed of about ninety knots, flew off in two waves from 170 miles out, at night, in November, against a harbour ringed with anti-aircraft guns and barrage balloons. The water at Taranto was shallow enough that a standard air-dropped torpedo would dive into the mud, so the weapons were modified with additional wires and a longer, flatter entry, and the crews had practised the approach for weeks. Two aircraft were lost. In one night, half of Italy's battleship strength was put on the bottom of its own harbour, and the balance of the Mediterranean shifted for a year. The consequences reached further than that. Japanese naval officers followed the raid closely, the assistant naval attache in Berlin travelled to Taranto in December 1940 to look at the damage and talk to Italian officers, and Commander Minoru Genda, who planned Pearl Harbor, studied it. The direct chain of influence is argued about by historians and the Japanese solved their own shallow-water torpedo problem independently, with wooden fins and a great deal of practice. But the essential proposition, that a fleet at anchor in a shallow harbour can be destroyed from the air, was demonstrated at Taranto thirteen months before it was demonstrated at Pearl Harbor, by twenty-one biplanes.

Absorbing a Beating No Other Carrier Could Survive

HMS Illustrious paid a heavy price for her success just two months later. On 10 January 1941, some 75 miles west of Malta, she was set upon during Operation Excess by the German Fliegerkorps X, dive bombers so drilled in anti-shipping work that many of their pilots had originally been earmarked to fly from Germany's own never-completed aircraft carrier, Graf Zeppelin. Seven direct hits from 550kg bombs tore into her, three punching clean through the flight deck to explode in the hangar below among fuelled aircraft, torpedoes and bombs; 126 of her crew were killed and 91 wounded. It was here that her armoured design proved its worth beyond question: naval historian J.D. Brown later wrote that 'the armoured deck saved her from destruction; no other carrier took anything like this level of punishment and survived', a notably remarkable testament to a design choice that had, at the time she was ordered, been a considerable gamble.

What happened next is the part usually left out, and it is the more remarkable half of the story. Burning, with her steering gone and her hangar wrecked, Illustrious was steered on her engines into Grand Harbour at Malta, arriving just after nine that night and berthing at Parlatorio Wharf under Corradino Heights. The Luftwaffe then set out to finish her where she lay. From 16 January 1941 the Germans mounted the heaviest raids the island had yet seen, two waves of forty-four Ju 87s and seventeen Ju 88s with fighter escort on the first day alone, aimed squarely at one damaged ship alongside a dockyard wall in the middle of a city. The Maltese, who had to live under it, have called it the Illustrious Blitz ever since. Bombs fell across the Three Cities, houses and churches came down, and the dockyard workers went on patching the ship. She was hit again and shaken repeatedly by near misses, and the yard got her steering back and her machinery working. On the night of 23 January she slipped out in the dark, worked up to twenty-three knots and was in Alexandria by early afternoon on the 25th. Malta paid for those eleven days for years afterwards.

HMS Illustrious underwent temporary repairs at Alexandria before transiting the Suez Canal and sailing all the way to the Norfolk Navy Yard in Virginia for permanent repairs, work that lasted from May to November 1941. On her return voyage that December, she collided with her own sister ship HMS Formidable, requiring yet further repairs at Cammell Laird, a frustrating coda to an already long and difficult recovery.

The American repair is a small period detail worth noticing. She went to the Norfolk Navy Yard in Virginia in May 1941 and stayed until November, which is to say that a British fleet carrier was rebuilt in a United States naval dockyard seven months before the United States entered the war. Lend-Lease had passed that March, and Roosevelt was stretching neutrality about as far as it would go; the practical effect was that Britain gained access to industrial capacity she simply did not have at home, since every British yard was full. Her ship's company spent six months in Virginia in a country still at peace, which several of them wrote about afterwards with a certain wonder. She came home, promptly ran into her own sister ship, and went into dock again at Birkenhead, which is the sort of thing that happens.

The Indian Ocean and the Pacific

HMS Illustrious took part in Operation Ironclad, supporting the invasion of Diego Suarez during the Madagascar campaign in May 1942, her aircraft flying 209 sorties, before further refits and a transfer to Force H for the Salerno landings in August 1943.

She joined the Eastern Fleet in January 1944 and, that April, sailed from Trincomalee alongside the American carrier USS Saratoga as part of a 27-ship task force to strike the Japanese base at Sabang in Sumatra, an operation codenamed Cockpit; Illustrious contributed 30 of the 91 attacking aircraft on 19 April. A second joint strike with Saratoga, against Soerabaya in Java that May, proved rather less rewarding, her sixteen Avengers and sixteen Corsairs inflicting comparatively little damage, a useful reminder that not every raid could be another Taranto.

Her most significant Far Eastern operation came in January 1945: Operation Meridian, a two-part strike on 24 and 29 January against the Japanese oil refineries at Palembang, launched alongside HMS Indomitable, HMS Indefatigable and HMS Victorious, nearly fifty Avenger bombers escorted by over seventy fighters attacking one of the last sources of aviation fuel still open to Japan. She then joined Task Force 57 of the British Pacific Fleet in March 1945 for the preliminary operations against Okinawa, flying 234 offensive and 209 defensive sorties during that campaign.

Palembang was the most important thing the Fleet Air Arm did in the entire war, and it is almost unknown. The two refineries there produced about half of Japan's oil and something like three quarters of her aviation spirit; without them the Japanese air forces could not fly. The two strikes, on 24 and 29 January 1945, were the largest operation the Fleet Air Arm ever mounted, flown at extreme range over mountains and defended by fighters, balloon barrages and heavy anti-aircraft fire, and they cut aviation fuel output from Sumatra to about a third of normal. It cost forty-one aircraft and thirty aircrew killed. Nine more men came down alive, were captured, and were taken to Changi in Singapore. They survived the raid, they survived captivity, and then, after Japan had surrendered in August 1945 but before the British got to Singapore, their captors executed them and put their bodies in a boat and sank it. They are remembered as the Palembang Nine, and they have a memorial in the Fleet Air Arm church at Yeovilton. Illustrious put nearly fifty bombers over that target with more than seventy fighters escorting them, in company with three of her sisters, and it is worth knowing what it cost.

A kamikaze near-miss on 6 April 1945 caused extensive hull damage, finally forcing her withdrawal from the front line that May, a fitting final action for a ship that had spent the entire war absorbing punishment other carriers simply could not have survived.

The kamikaze period is where the two schools of carrier design finally got a fair test, and the results were embarrassing for one side. When a kamikaze hit an American carrier with a wooden flight deck the ship usually survived but the deck did not, and repairs took months in a dockyard. When one hit a British armoured deck the usual result was a dent, a fire party and flying operations resumed the same day. American officers watching it said so at the time, in the plainest terms. What that comparison hides is the cumulative cost to the British ships themselves: the shock of repeated near misses works the hull, and Illustrious in particular never fully recovered from January 1941. The damage from the near miss of 6 April 1945 was, in effect, added to four years of accumulated distortion, and it was that rather than any single blow which took her out of the line in May. She had been hit, blown up, bombed alongside, rammed by her own sister and shaken by more explosions than anybody counted, and she was still steaming.

By the time she left the front line, Illustrious had flown 725 offensive sorties over the course of the war, her fighters had claimed 51 enemy aircraft destroyed, and between them her squadrons had sunk six enemy warships and six merchant vessels, a tally that earned her battle honours stretching from Taranto and the Malta convoys to Diego Suarez, Salerno, Sabang, Palembang and Okinawa, about as comprehensive a Second World War record as any carrier in the fleet could claim.

A Trials Carrier, Then Retirement

HMS Illustrious was spared from the planned invasion of Japan and instead converted into a Home Fleet trials and training carrier, conducting deck-landing trials for most of Britain's postwar naval aircraft through the early 1950s, including the first turboprop carrier landing by a Fairey Gannet in June 1950 and the first swept-wing carrier landings by a Supermarine 510 that November, properly important pioneering work at the dawn of the jet age.

Her final job was more consequential than trials carrier makes it sound. British naval aviation in 1950 faced a genuine crisis: jets were heavier, faster and landed at speeds that made the wartime arrangement of a straight deck, arrester wires and a crash barrier lethal. The three inventions that solved it were all British, all developed in that decade, and all needed a ship to try them on: the angled flight deck, so that a pilot who missed the wires could fly off again instead of hitting the barrier; the steam catapult, powerful enough to launch a loaded jet; and the mirror landing sight, which replaced a man with two bats waving at the pilot. Illustrious spent the early 1950s doing the groundwork for that, taking the first turboprop aboard in the Fairey Gannet in June 1950 and the first swept-wing aircraft in the Supermarine 510 that November, and running through a thousand deck landings. Every carrier in the world today uses all three of those British ideas, and a good deal of the early trials work was done on a ship the Germans had spent eleven days trying to destroy in 1941.

She ferried troops to Cyprus during civil unrest in November 1951 and took part in the Coronation Fleet Review in June 1953, completing 1,051 deck landings by April 1954.

She was paid off at the end of February 1955, placed in reserve at Gareloch, sold on 3 November 1956, and broken up in early 1957, closing out the career of a carrier whose armoured deck had, quite literally, saved her from a fate that befell so many of her less well-protected contemporaries.

She was seventeen years old when she went to the breakers, which looks premature until you count what she had absorbed. Illustrious was one of the very few ships in the Royal Navy to fight in every theatre the war had: the Mediterranean, the Atlantic approaches, the Indian Ocean, the East Indies and the Pacific. She proved the carrier strike at Taranto before anybody else did, she proved the armoured deck at Malta at a cost of 126 of her people, she helped take the aviation fuel away from the Japanese air forces, and she spent her last years teaching the Royal Navy how to fly jets off ships. There is a case that she was the single most influential warship Britain built in the 1930s, and the fact that she is remembered chiefly for what she survived rather than for what she did is a little unfair on her.