Casablanca-class Escort Carrier

The same industrial method that produced the Liberty ships was turned on aircraft carriers, by the same man. Henry J. Kaiser proposed building escort carriers on a merchant-style hull using assembly-line techniques, and between 3 November 1942 and 8 July 1944 his Vancouver, Washington yard laid down, launched and commissioned fifty of them — roughly one every three weeks.

That makes the Casablanca the most numerous class of aircraft carrier ever built, by a distance that will not be closed. For comparison, the entire Japanese carrier force at the start of the war amounted to ten ships. The United States commissioned five times that number of this one class alone while also building the fleet carriers, and it did so in twenty months.

They were small: about 156 m long, roughly 10,900 tonnes at full load, and capable of 19 knots — fast enough to work with convoys and amphibious groups, far too slow to operate with the fleet carriers. The air group was around 28 aircraft, typically FM-2 Wildcats and TBM Avengers: fighters that could still fly off a short deck, and torpedo bombers for anti-submarine work.

There was no armour, no torpedo protection and very little anti-aircraft armament, because the hull underneath was a merchant design and the whole point was to build it quickly. Their crews drew the obvious conclusion and turned the designation into a joke: CVE stood officially for escort carrier, and unofficially for Combustible, Vulnerable, Expendable.

Their intended jobs were the unglamorous ones that the fleet carriers could not spare aircraft for: escorting convoys and hunting submarines, ferrying aircraft across oceans, and above all providing close air support over amphibious landings — circling off a beachhead for days on end, putting aircraft over the troops while the fast carriers went hunting the enemy fleet.

That division of labour is what made the Pacific advance possible at the pace it happened. An island landing needed continuous air cover, and every day a fleet carrier spent flying support missions off a beach was a day it was not available to fight. The escort carriers absorbed that burden — and it is worth being accurate about the geography: the Casablancas served overwhelmingly in the Pacific, while the Atlantic hunter-killer groups that closed the mid-ocean air gap were built mainly around the earlier Bogue-class ships and their Royal Navy equivalents.

On the morning of 25 October 1944, off Samar in the Philippines, a unit called Taffy 3 — six Casablanca-class escort carriers with three destroyers and four destroyer escorts — found itself alone in front of a Japanese battle force built around the Yamato. The American ships were unarmoured, made 19 knots, and had aircraft armed for ground support rather than for sinking battleships. By every reasonable expectation they should have been annihilated.

Instead they attacked. The escorts charged with torpedoes, the carriers ran and launched everything they had, and aircraft made repeated dummy runs after their ammunition was gone, forcing Japanese ships to manoeuvre against attacks that could no longer hurt them. The destroyer USS Johnston fought until she was destroyed. USS Gambier Bay was sunk by gunfire — the only American carrier of the war destroyed by surface fire — and three escorts went down with her. But after roughly two and a half hours the Japanese commander, unable to believe that ships this aggressive were escort carriers and convinced he had run into a fast carrier force, broke off and withdrew. Taffy 3 lost five ships and saved the invasion beachhead behind it.

The same day brought the other event these ships are remembered for. USS St. Lo, another of Taffy 3’s carriers, was hit by an aircraft flown deliberately into her deck — the first ship sunk by a kamikaze attack. She exploded and went down within half an hour.

It was a demonstration with consequences far beyond one ship. An unarmoured wooden flight deck packed with fuelled and armed aircraft is close to the ideal target for a deliberate crash, and the escort carriers were the most vulnerable major ships in the fleet to precisely that attack. The campaign that opened that morning off Samar would dominate the last ten months of the Pacific war.

Five Casablancas were lost during the war, and the manner of the losses tells the story of the design: sunk by gunfire, by kamikaze and by submarine torpedo. When they were hit they burned and went down fast — a merchant hull filled with aviation fuel and ordnance has very little margin, and no armour anywhere to slow a hit down. Damage that a fleet carrier absorbed and kept flying from was, on a jeep carrier, frequently fatal within the hour.

Their crews knew all of this. What made the ships work was not that the risk was acceptable to the men aboard but that it was acceptable to the Navy: an escort carrier cost a fraction of a fleet carrier and could be replaced in weeks. Kaiser delivered 50 of them in 20 months, roughly one every three weeks, and the five that were lost included USS Gambier Bay, the only American carrier sunk by surface gunfire, and USS St. Lo, the first ship sunk by a kamikaze — both on 25 October 1944.

The clearest way to see what the Casablanca meant is to set it beside the ship at the opposite extreme. Japan converted the hull of a Yamato-class battleship into the Shinano, the largest aircraft carrier in the world, and lost her to a submarine ten days after commissioning. In the same period the United States commissioned escort carriers at a rate of one every three weeks and could absorb the loss of five of them without the campaign slowing.

That is the whole argument of the industrial war in two ships. The Casablanca was not a good carrier by any standard the fleet carriers set — slow, unarmoured, small in capacity, and honest enough about it in its crews’ nickname. It was, however, available in quantities that changed what the US Navy could attempt, and once, off Samar, it turned out to be enough to make a battleship force turn round.

• Roger Chesneau (ed.), Conway’s All the World’s Fighting Ships 1922–1946 (Conway Maritime Press).
• James D. Hornfischer, The Last Stand of the Tin Can Sailors (Bantam Books).
• Norman Friedman, U.S. Aircraft Carriers: An Illustrated Design History (Naval Institute Press).