Royal Navy growth patterns challenge fixed tonnage labels. Britain was approaching 10,000-ton light cruisers by the end of the First World War, even though later treaty language makes that displacement sound like heavy-cruiser territory. Continued development could have pushed cruiser designs toward roughly 18,000 tons. Battlecruisers grew even more dramatically, from about 20,000 tons to Hood's roughly 47,000 tons. Classification depends on role, lineage, and period as well as displacement.
Notable Point · 47:33-48:31
Why tonnage alone does not define a cruiser or battlecruiser
Warship categories changed while designs grew, so a tonnage treated as heavy-cruiser scale in one era could describe a light cruiser in another.