Could a wartime penalty of three to five times normal machinery wear have sealed the postwar fate of some First and Second World War ships?
Short answerYes; wartime operations discard peacetime safety and maintenance margins, so machinery is driven far harder and can consume several times its normal service life.
NotesThe exchange accepts a rough three- to fivefold wartime penalty on machinery life. Published peacetime operating limits assume safe, maintainable use and time for regular upkeep. War removes many of those margins because immediate survival and maximum power take priority. A ship can survive the conflict yet consume enough machinery life that restoring it is no longer economical. Calendar age alone therefore understates the condition of ships considered for postwar retention.