Testing Thornycroft and Yarrow destroyer ideas

Buying torpedo boats alongside destroyers kept both options open while Japan decided which type best suited its requirements. The larger Shirakumo and Akatsuki classes were initially ordered as strike leaders, with two ships from each of Thornycroft and Yarrow. They were roughly 50 tons heavier than their predecessors, with crews about twelve people larger and the familiar gun-and-torpedo fit retained. Thornycroft pursued extreme speed, while Yarrow emphasized manoeuvrability, so the orders compared two distinct design philosophies. The Thornycroft-built Shirakumo class exceeded its 30-knot requirement and approached 32 knots during exercises. Reports of the hulls beginning to plane capture the yard's aggressive pursuit of speed.