Why underwater-protection trials can mislead

Brown's account of early torpedo-protection trials shows how difficult it is to generalize from a single underwater explosion. In 1903, a test system used water, cork, coal, air, and a second coal space across twelve feet of depth, yet a 230-pound guncotton charge ruptured every bulkhead and shifted a boiler by two feet. A later merchant-ship trial made a single thick bulkhead look successful and encouraged similar protection in HMS Dreadnought. The idea rested on a mistaken reading of Russian experience during the Russo-Japanese War, another warning about turning the Battle of Tsushima into a simple design lesson. In a 1914 trial against the old battleship HMS Hood, a 280-pound charge opened a hole about thirty feet long and eighteen feet high. Empty compartments suffered the worst effects, while a light bulkhead was driven into and severely dished the heavier one behind it. Compartment condition, bulkhead arrangement, and the variability of underwater explosions all matter before a successful test becomes fleet design practice.