Tsushima strengthened an all-big-gun design case that the Royal Navy had developed through roughly a decade of exercises. Reports from the battle encouraged First Sea Lord Jacky Fisher to accelerate the program. A large gun could still engage at medium or short range, whereas smaller weapons could not duplicate its long-range effect. Standardizing on the largest useful caliber simplified fighting power, ammunition supply, and other logistics while avoiding a mixed battery's complications. The battle confirmed the case for HMS Dreadnought and accelerated its construction program.
Notable Point · 6:30-8:42
How Tsushima accelerated HMS Dreadnought
The Battle of Tsushima strengthened Fisher's case for all-big-gun battleships, but British exercises had already pushed design in that direction.