The class used eight boilers and four geared steam turbines to drive four shafts, with published top speeds around 33 or 34 knots. A listed naval speed usually represents what a ship can achieve safely under normal peacetime operating rules in this interpretation. In an emergency, a navy might accept severe machinery wear or later boiler and engine replacement to extract more power. Because resistance rises steeply with speed, that extra strain may buy only a few knots. Even a small margin can matter during a critical operation.
Notable Point · 21:22-22:48
Rated carrier speed leaves an emergency margin
The published 33-to-34-knot figure is treated as a safe peacetime rating, with only a small and costly machinery margin available in an emergency.