Seawater or fuel loading could help absorb and distribute a torpedo explosion. Effectiveness depended on the complete layered system rather than the presence of liquid alone. British testing and the traumatic loss of Aboukir, Hogue, and Cressy pushed torpedo defense high on the design agenda. Because water and fuel were excluded from standard displacement, liquid loading also improved protection without consuming treaty tonnage. Interwar designers combined experimental results and wartime experience while exploiting the treaty's wording.
Notable Point · 2:54:06-2:58:24
Liquid loading in torpedo-protection systems
Liquid-filled compartments could spread explosive force, but designers had to balance that benefit against weight, flooding behavior, and the details of the protection scheme.