Illustrious took 1,124 days to build, while Formidable took 1,256 days and Victorious and Indomitable took more than 1,400 days. An assumed average of 1,200 days brings Formidable into service in September 1940, Victorious in August 1940, and Indomitable in February 1941. These estimates use ordinary peacetime working patterns without extra shifts or exceptional production efforts. Earlier availability could put two or three Illustrious-class carriers into the Taranto operation. Victorious would also have months to prepare her air group before the historical Denmark Strait crisis, instead of sending it into action almost immediately after entering service.
Chapter · 27:22-29:34
Earlier Illustrious-class carriers bring trained air groups to battle
An assumed 1,200-day build puts Formidable and Victorious into service in 1940, increasing availability and air-group preparation time.