Small-tube oil-fired boilers are presented as the most plausible missed improvement and might have produced 28-knot Queen Elizabeths. With a European war possible, the Royal Navy still favored proven large-tube boilers, twin turrets, and the 15-inch gun. Each conservative choice reduced the chance that an unfamiliar boiler, turret, or gun would delay ships beyond the conflict they were meant to deter or fight. The class was a conservative revolution, powerful enough to win its race while leaving much of Britain's maximum design capacity unused.
Notable Point · 52:58-1:04:12
Small-tube boilers and conservative revolution
The boiler discussion argues that small-tube oil-fired boilers could have made the class faster, but the known option reduced wartime risk.