As light forces close for a torpedo attack, a battleship's six-inch battery provides the immediate defence. Heavy guns dominate the long-range engagement, while rapid secondary fire can break up cruisers and destroyers before they reach a viable launch position. Battleship armament was therefore a layered system rather than a main-battery specification alone. That protection still depends on crews and fire control actually employing the secondary guns.
Notable Point · 1:21:47-1:22:15
Why battleships carried heavy secondary batteries
Six-inch secondary guns give a battle line the volume of fire needed to stop cruisers and destroyers before they reach torpedo range.