Armored Aircraft Carriers: Great Britain's Secret World War II Wonder Weapon?

Armored Aircraft Carriers: Great Britain's Secret World War II Wonder Weapon?

You decide. 

HMS Victorious was first assigned to the British Home Fleet, and in the spring of 1941 her planes were involved in the pursuit of the German battleship Bismarck. On May 24, a flight of nine Swordfish launched from her decks attacked the German battleship, but only one of their torpedoes struck the target, causing minimal damage.

British Carriers Join Pacific War

After her commissioning, Indomitable was assigned to the Indian Ocean in early 1942, along with Formidable, after the veteran ship’s repairs were completed, and HMS Hermes, one of the Royal Navy’s older carriers. Britain was now at war with Japan, and a task force of five carriers and five battleships was directed to seize control of the Indian Ocean. A Japanese attack on the British base at Colombo, Ceylon, inflicted major damage, but the Royal Navy force had withdrawn. A counterattack by the British failed when it was met by Japanese carrier aircraft. Two cruisers and Hermes were sunk. Indomitable participated in the invasion of Madagascar, then was brought back to England for convoy duty protecting ships bound for Malta. Like Formidable and Illustrious, Indomitable also suffered major battle damage at the hands of the Luftwaffe.

As German and Italian air and sea power began waning in the Mediterranean, the Royal Navy carriers were assigned to a supporting role, providing air cover for Allied amphibious operations in Sicily. With the need for sea power in the European Theater reduced, Britain was able to contribute more of its resources to the Pacific where carrier-based air power was continuing to play a major role.

HMS Victorious Allies With American Pacific Fleet

The first of the armored carriers to operate in the Pacific was Victorious. Upon completion of repairs and refitting in Norfolk, Victorious was loaned to the U.S. Navy, which was still short of carriers in the spring of 1943, and sent to Pearl Harbor to join U.S. Task Force 14, which was led by the USS Saratoga. Task Force 14 set sail for the Southwest Pacific and conducted air strikes against Japanese targets in the Solomon Islands. As camouflage, the U.S. Navy referred to Victorious as the USS Robinin dispatches and radio communications. The British carrier operated with the U.S. Navy in the Southwest Pacific until late 1943, then she returned to England for duty with the Home Fleet. A year later Victorious was once again in Pacific waters.

For the balance of the war, the major effort of the British Home Fleet carriers was the attempt to sink the German battleship Tirpitz. Victorious and Formidable, along with Indefatigable, one of the last two of the armored carriers to be commissioned, participated. Between January 1942 and August 1944, Fleet Air Arm aircraft launched from carriers participated in 10 raids against the battleship, although most were frustrated by bad weather or smoke screen. In April 1944, the Home Fleet launched a major offensive against Tirpitz, which at the time was undergoing repairs in the Norwegian port at Altenfjord. An attack by planes from Victorious and the carrier Furious on April 3, 1942, inflicted major damage to the ship’s superstructure, but did little damage to the hull. Home Fleet carrier aircraft continued operations against Tirpitz until August 1944, when the Royal Navy began directing its efforts toward the Pacific.

Illustrious Returns To Duty

In early 1944, HMS Illustrious returned to the Indian Ocean for duty with the Eastern Fleet. In a reversal of the earlier program when the Royal Navy lent Victorious to the U.S. Navy, the Americans lent the USS Saratoga to the British to serve with Illustrious for operations against Japanese targets in Java and Sumatra.

Later in the year, Illustrious was joined in the Pacific by her sister ship Victorious, along with Indomitable and the new carrier Indefatigable, to make up Task Force 63. The four carriers moved northeastward for air operations against the Japanese garrisons on islands that were being bypassed as General Douglas MacArthur’s Southwest Pacific Area of Operations forces moved northward from New Guinea to the Philippines.

Britain Forms Task Force 57 In South Pacific

As the American forces concentrated their efforts northward, British and Commonwealth forces were given responsibility for pressing the Japanese in Sumatra and Java. At the end of 1944, the Royal Navy dissolved the old Eastern Fleet and replaced it first with the East Indies Fleet, and subsequently with the British Pacific Fleet. Illustrious, Indefatigable, Indomitable, and Victorious were all allocated to the new fleet, which was designated as Task Force 57.

In mid-March 1945, Task Force 57 joined the Allied Fifth Fleet and took up a station off of Sakashima Gunto, in the Ryukyu Islands, which include Okinawa. The Allies had begun pre-invasion bombardment in preparation for landings that had been scheduled on Sunday, April 1.

Japanese Unleash First Kamikaze Attacks

The initial Japanese kamikaze attacks of the war had taken place in the Philippines and gradually intensified as the fighting neared the Home Islands. Indefatigable was the first British carrier to sustain a hit by a kamikaze—on the day of the invasion. However, the carrier’s armored deck prevented major damage. Within an hour, her flight deck was operational again. Illustrious was next to be hit when she was struck by a kamikaze on either April 6 or April 9 (accounts differ) and somehow suffered damage beneath the waterline that forced the ship to withdraw to Leyte. By this time, the Illustrious had been in service for more than four years and had suffered a great deal of punishment. After temporary repairs, Illustrious continued southward to Sydney, Australia, then back to England. In five years of combat, the carrier had accrued a combat record that lived up to her name.

Formidable started for the Pacific in September 1944, but diverted into Gibraltar for repairs after a mechanical problem. In January she left to continue her journey to join the Pacific War and arrived on station on April 15, 1945, relieving Illustrious. Formidable took several kamikaze hits during the battle for Okinawa but was able to remain operational, at least in part due to her armored decks. Planes flying from Formidable participated in air strikes against the Japanese Home Islands during the final weeks of the war.

War’s End Nears

Indomitable took a kamikaze hit on May 4, but the Japanese plane simply slid along the flight deck and went over the side, causing minimal damage. Victorious took her first kamikaze hit on May 9, but the damage was minimized by the armored deck and she continued in the fight.

Implacable was the last of the armored deck carriers to be commissioned and the last to arrive in the Pacific. Her combat career in the European Theater had been limited to anti-shipping operations off the Norwegian coast, and the carrier was damaged in a storm and forced into dry dock for repairs in December 1944. Implacable departed for the Far East to join the Pacific Fleet, but the battle for Okinawa ended before she got there. After some “training strikes” against the bypassed Japanese installations on the fortress island of Truk in the Carolines group in mid-June, Implacable moved north in time to take part in the carrier strikes against the Japanese Home Islands.

Armored Decks Prove Their Worth

No doubt, due at least in part to their armored flight decks, all six of the carriers survived the war. There can be little doubt that the armored decks saved Illustrious from destruction and that they similarly protected Formidable. The armor under the decks allowed the British carriers to continue to operate after kamikaze strikes in the Okinawa campaign when they sustained hits that would probably have put U.S. carriers out of action for extended periods.

The armored decks of the British Illustrious-class aircraft carriers represented a differing philosophy from that of U.S. Navy carrier designers. The Americans had chosen to employ wooden flight decks, sacrificing some degree of protection for greater aircraft capacity.

The debate continues as to which design was ultimately superior. However, each proved its worth in differing circumstances. The British carriers were able absorb great punishment and remain afloat; however, the Americans were able to put larger numbers of planes in the air during the early, critical stages of the War in the Pacific.

Originally Published in 2018.

This article by Sam McGowan originally appeared on the Warfare History Network.