The Commencement Bay-class escort aircraft carriers were the last class of escort carriers built for the US Navy in World War II. The ships were based on the Maritime Commission type T3 Tanker hull, which gave them a displacement of approximately 23,000 tons and a length of 557 feet (170 m). Unlike most earlier escort carrier classes, which were laid down as something else and converted to aircraft carriers mid-construction, the Commencement Bays were built as carriers from the keel up. Their general layout was similar to the Sangamon-class escort carriers, but some of the Sangamon's engineering shortcomings were addressed.