The Kongo class began as a strong battlecruiser design and received extensive modernization, but the four ships did not emerge with identical protection. Some reconstructions added enough subdivision to approach lightly armored fast-battleship status, while others remained more clearly battlecruisers. Survivability depends on armor thickness, the area that armor covers, and internal subdivision together. A large gun caliber does not by itself settle the classification. The uneven modernization explains why Mikawa had to treat the ships as valuable but vulnerable combatants rather than conventional battle-line equals.
Notable Point · 24:17-25:40
Why the modernized Kongos remained risky combatants
Armor thickness, coverage, subdivision, and uneven reconstruction standards left individual Kongo-class ships on different sides of the battlecruiser and fast-battleship boundary.