London Naval Treaty exemptions shaped small-warship choices

Article 8 exempted naval combatants of 600 tons or less from numerical limitation. It also exempted vessels up to 2,000 tons if they did not carry guns above 155 mm, mount more than four guns above 76 mm, launch torpedoes, or exceed 20 knots by design. These thresholds explain why a nominally small torpedo boat could become an attractive way to preserve combat power outside the destroyer totals. They also created sharp design incentives around declared displacement, speed, armament, and later conversion. This passage is useful for reading the Japanese examples as responses to a legal regime rather than as isolated technical curiosities.