Protecting Eagle with bulges would have cost speed or availability

Alex Clarke recalls a naval-architecture training exercise in which his father and fellow trainees considered how lost wartime ships might have been better protected. Their proposal was to fit Eagle with sufficiently large protective bulges, which might have allowed her to survive the torpedo damage. The estimated penalty was severe: speed would fall from about 24 knots to roughly 16 to 18 knots. Avoiding that loss would have required a much longer reconstruction and a lengthy absence from service. Eagle and other early carriers remained in use because replacements had not arrived soon enough. The explanation links that shortage to the Ten Year Rule, distinguishing its formal end in 1932 from the argument that its practical effects continued until 1937.