How much faster would Queen Elizabeth-class battleships be with small-tube boilers?
Short answerAbout 26 knots is plausible; reaching 28 knots would likely require a longer hull as well as the boilers.
NotesThe answer estimates roughly 26 knots and perhaps 28 knots if the hull were lengthened. Small-tube boilers could provide the power, but the original length-to-beam ratio still limits speed. Adding roughly ten to fifteen metres offers naval architects a way to improve the hull form without abandoning the protected battleship concept. Propulsion power alone cannot overcome the hydrodynamic demands of a broad, heavily protected hull.