Escort carrier

The escort aircraft carrier or escort carrier, was a small aircraft carrier utilized by the Royal Navy, the Imperial Japanese Navy and the United States Navy in World War II. In the Atlantic the escort carriers were employed to deal with the U-boat crisis of the Battle of the Atlantic, while in the Pacific they provided air support to ground forces during amphibious operations, served as backup aircraft transports for fleet carriers, and transported aircraft of all military services to points of delivery.

World War II

The first escort carrier was HMS Audacity which was converted from the captured German merchant ship MV Hannover and commissioned in July 1941. She was followed by additional Royal Navy merchant ship conversions. Similarly, Audacity became the model for U.S. built escort carriers, the first example of which was the USS Long Island (AVG-1).

In US service, they were initially referred to as auxiliary aircraft escort vessels (hull classification symbol AVG) and then auxiliary aircraft carrier (ACV) before the Navy settled on the type description escort aircraft carrier (CVE). They were informally known as "Jeep carriers" or "baby flattops." It was quickly found that the escort carriers were better aircraft platforms than the light carriers, which tended to pitch badly in moderate to high seas, and as a result, many more of them were ordered.

CVE was sarcastically said to stand for "Combustible, Vulnerable, and Expendable". This was borne out to an extent by the fact that three escort carriers — USS St. Lo, USS Ommaney Bay and USS Bismark Sea — were destroyed by kamikazes, the largest ships to meet such a fate.

Allied escort carriers were typically around 500 ft (150 m) long, not much more than half the length of the almost 900 ft (300 m) fleet carriers of the same era, but actually less than one-third of the size: a typical escort carrier displaced about 8,000 tons, as compared to almost 30,000 tons for a full-size fleet carrier. The aircraft hangar typically ran only a third of the way under the flight deck and housed a combination of 24 to 30 fighters and bombers organized into one single 'composite squadron'. (A late Essex class fleet carrier could carry a total of 103 aircraft organized into separate fighter, bomber and torpedo-bomber squadrons)

The island on these ships was small and cramped, and located well forward of the funnels (unlike on a normal-sized carrier where the funnels were integrated into the island). Although the first escort carriers had only one aircraft elevator, two elevators, one fore and one aft, quickly became standard, so did the one aircraft catapult. The carriers employed the same system of arresting cables and tailhooks as on the big carriers, and procedures for launch and recovery were the same as well.

The crew size was less than a third of that of a large carrier, but this was still a bigger complement than most naval vessels. It was large enough to justify the existence of facilities such as a permanent canteen or snack bar, called a gedunk bar, in addition to the mess. The bar was open for longer hours than the mess and sold several flavors of ice cream, along with cigarettes and other consumables. There were also several vending machines, which made a "gedunk" sound when operated.

Originally developed at the behest of the United Kingdom to operate as part of a North Atlantic convoy escort rather than as part of a naval strike force, many of the escort carriers produced were assigned to the Royal Navy for the duration of the war under the Lend-lease act. They supplemented and then replaced the converted merchant aircraft carriers which were put into service by the British and Dutch as an emergency measure until the escort carriers became available. As convoy escorts, they were used by the Royal Navy to provide air scouting, to ward off enemy long-range scouting aircraft and, increasingly, to spot and hunt submarines. Often additional escort carriers also joined convoys, not as fighting ships but as transporters, ferrying aircraft from the US to Britain. In this case the aircraft cargo could be doubled by storing aircraft on the flight deck as well as in the hangar.

The ships sent to the Royal Navy were slightly modified, partly to suit the traditions of that service. Among other things the ice cream making machines were removed, since they were considered unnecessary luxuries on ships which served grog and other alcoholic beverages. The heavy duty washing machines of the laundry room were also removed since "all a British sailor needs to keep clean is a bucket and a bar of soap" (quoted from Warrilow).

Other modifications were due to the need for a completely enclosed hangar when operating in the North Atlantic and in support of the Arctic convoys.

Meanwhile the US discovered their own use for the escort carriers. In the North Atlantic, they would supplement the escorting destroyers by providing air support for their anti-submarine warfare. One of these escort carriers, the USS Guadalcanal, was instrumental in the capture of the German submarine (U-boat) U-505 off North Africa in 1944. The Guadalcanal and her task force were commanded by Captain (later Admiral) Daniel V. Gallery. (In 1955 the U-505 was moved to Chicago, restored, and made a permanent exhibit at the Chicago Museum of Science and Industry.)

In the Pacific theatre, the escort carriers would often escort the landing ships and troop carriers during the island hopping campaign. In this role, they would provide air cover for the troopships as well as fly the first wave of attacks on the beach fortifications in amphibious landing operations. On occasion they would even escort the large carriers, serving as emergency airstrips and providing fighter cover for their larger brothers while these were busy readying or refueling their own planes. In addition to this, they would also transport aircraft and spare parts from the US to the remote island airstrips.

Perhaps the finest moment for these escort carriers was the Battle of Leyte Gulf's Battle off Samar, where three escort carrier groups, along with their escort destroyers, fended off the battleships of the Japanese Combined Fleet, allowing General Douglas MacArthur's Army to complete the liberation of Leyte. The hero of the battle was Rear Admiral Clifton "Ziggy" Sprague.

In all, 130 escort carriers were launched or converted during the war. Of these, six were British conversions of merchant ships: HMS Audacity, HMS Nairana, HMS Campania, HMS Activity, HMS Pretoria Castle and HMS Vindex. The remaining escort carriers were US-built. Like the British, the first US escort carriers were converted merchant vessels (or in the Sangamon class, converted military oilers). Later carriers were built using the hulls of Liberty Ships not yet finished but already in various stages of construction. The last 69 escort carriers of the Casablanca and Commencement Bay classes were purpose-designed and purpose-built carriers drawing on the experience gained with the previous classes.