An escort carrier is an extremely small ship used to carry fighters. They were no larger than a big Destroyer. It's fighter capacity was smaller than nearly any Light carrier, it was small and very suitable for mass production. They were designed for that reason. Hannah Avram designed them during the Seige of Danzig. Hannah had them produced because she needed the ships fast and a small ship is much more suitable for true mass production when production capacity is limited. This is also shown when she opted for over thirty destroyers while only building four Battlecruisers. The first class was the Sand-Fly class escort carrier which Hannah used. By the time Danzig was liberated she had over 14. They were also critical to the Battle of Thebes. By the time of ISW-4 they were a hopeless fleet unit because of their extremely light armor. They simply could not survive if they were but in range of enemy missile batteries. Another threat was the Arachnids Gunboats. And yet, people still found much use in them. While not viable battle line units, they were a cheap way to ferry fighters through Warp points. They could also help bolster battle line units by replacing combat loses and what-not. They could also funcion as frontier pickets and warp point defense units.