Armor and machinery choices for a two-decker Warrior

The proposed two-decker would probably retain Warrior's armor thickness and protection concentrated around the fighting citadel and machinery. Extending that arrangement to a much larger ship would complicate the structural calculations. Historical Warrior used a single shaft and trunk steam engine supplied by ten boilers, with output put at roughly 5,772 indicated horsepower. That horsepower figure comes with a caution about the period's limited precision in calculating and understanding engine output. The enlarged ship might need a more powerful engine or a second engine to retain speed. Heavy engines and boilers low in the hull would also help lower the center of mass. The arrangement remains unresolved: a single engine, perhaps even the same engine, is considered possible if the length-to-beam ratio stays similar and additional space permits more boilers and fuel.