The good people at Vintage Wings of Canada have put up an amazingly long and detailed article (about 33,000 words and scores of photographs) about the 44 escort carriers, built on merchant ship hulls, that were built in the USA for service with the Royal Navy (out of 123 escort carriers built in total). It's a fascinating look at the 'workhorse' carriers of the ocean war, in any navy - not just the British. Here's an excerpt from the introduction.
During the Second World War, there were literally hundreds of vessels on all sides that could be classified as aircraft carriers; from merchant vessels with a single catapult-launched Hurricane to seaplane carriers to merchant aircraft carriers (similar to an escort carrier but without a hangar deck) to the biggest aforementioned fleet carriers. Of these, the largest number were escort carriers, the ships we have come to know as “baby flattops”. There were an astonishing 123 escort carriers built for the United States Navy, many of which were transferred to the Royal Navy after launch. These so-called “baby” aircraft carriers were hardly small—around 500 feet in length, carrying dozens of aircraft, displacing 8,000 tons and capable of speeds up to 20 knots.
HMS Nabob showing damage after being torpedoed in August 1944
While the big fleet carriers took the fight directly to the enemy and received the attention of the folks back home, the escort carriers did a myriad of necessary tasks that underpinned the very concept of carrier aviation—ferrying aircraft, replenishing aircraft, fuel and stores and carrying troops, as well as taking the fight to the enemy with anti-submarine sweeps, convoy escort, “spare deck” duty, and attacks on enemy shipping and land installations. They were the true all-purpose aviation vessels of the Second World War. The big boys made history in such battles as Leyte Gulf, Midway, Coral Sea, Santa Cruz, Taranto and Pearl Harbor, but the baby flattops supported, supplied, and suffered along with them from Operation TUNGSTEN to Operation ICEBERG. In fact, the first warship to be sunk by a kamikaze attack was the Casablanca-class escort carrier USS St. Lo in the battle of Leyte Gulf.
HMS Emperor in a snowstorm off Newfoundland
Though all of these carriers were launched with American names, many did not serve with the United States Navy. Instead, 44 escort carriers were transferred to the Royal Navy after launch and completion under the Lend-Lease program and renamed.
. . .
Some were relegated to the drudgery of aircraft ferrying and one or two never even launched a single aircraft, but most saw some combat activity either in the high arctic waters off Norway, in the swelter of the Indian Ocean or with the Royal Navy’s Pacific Fleet.
during combat operations in the Aegean Sea in September 1944
Unlike fleet carriers, escort carriers of both the United States and Great Britain had lives after their fighting careers were over. Nearly all of them sold to commercial shipbuilders after the war and were stripped down to their base mercantile hulls, then rebuilt as cargo vessels, many of which, at nearly 500 feet long, were the largest of their day. A few of them even became luxury ocean liners. These often-beautiful merchant vessels continued on for another 20–25 years or more, with most going to the breakers in the 1970s.
Former escort carrier HMS Atheling after post-war conversionto the Italian passenger liner SS Roma
There's much more at the link, including many more photographs.
This is truly fascinating stuff for naval and military history buffs. I'm not aware of any other detailed history of escort carriers and their activities (at least, not one that's currently available - there may be older books out there, but I don't know of any in print). I learned a great deal that I didn't know, such as combat operations by escort carriers against German forces in Norway, Crete and the Dodecanese Islands, and strikes against Japanese positions in Burma and other 'sideshow' campaigns of the Pacific War. I also gained a new respect for the way these small carriers supplied aircraft and essential supplies to the larger fleet carriers. It's clear that, without the escort carriers to resupply them and replenish their aircraft inventories as they were depleted by battle losses and damage, the fleet carriers would often have become white elephants until they could return to port to resupply.
Highly recommended as a possibly unique resource on a little-known aspect of naval warfare in World War II.