The water-filled torpedo-bulge principle also applied to coal and fuel. Coal bunkers could absorb damage while the coal still counted as a consumable rather than permanent protective weight. That made the treaty definition of standard displacement an important design variable rather than a neutral accounting measure. British negotiators helped shape a definition from which the Royal Navy could extract practical advantages.
Notable Point · 1:34:57-1:35:32
Using fuel as armor under treaty rules
Coal bunkers and other consumable loads could contribute to protection without being charged like permanent armor under standard-displacement rules.