Building a fast battlecruiser with room to grow

The first battlecruiser is built around twelve-inch guns, six-inch secondary armament, torpedo protection, and enough armour to survive likely threats. Speed, beam, weapon range, and weight are adjusted together because each choice affects the others. Deck armour is retained because it improves machinery efficiency, while a two-funnel arrangement leaves room for later development. Layout choices that appear cosmetic can therefore affect modernization and operational performance.