The 1,500-ton destroyer limit cited for the London treaty left less room for another Akatsuki-sized design. Hatsuharu put heavy armament into a smaller hull. The approach stretched earlier second-class destroyer designs to carry the desired armament. A long, narrow hull favours speed, but becomes harder to keep stable as weight accumulates high above the waterline. Ballast can improve stability, although the extra displacement pushes the hull deeper into the water and reduces speed.
Chapter · 55:29-57:41
Hatsuharu and the smaller treaty destroyer
A 1,500-ton treaty limit pushed Japan toward smaller destroyers, bringing speed, hull shape and stability into tension.