Capital ships as a moving spectrum

In this interpretation, battlecruiser and fast-battleship labels form a spectrum that moves as technology changes. Machinery power-to-weight ratio, armor, subdivision, and hull structure determine what designers can combine in one ship. The proposed G3 illustrates why comparisons need a contemporary reference point. Beside the heavily protected N3 design, G3 would appear lightly armored and retain its battlecruiser identity in this argument, even though later observers may call it a fast battleship. Improvements in engines and construction shift the range of possible designs, so a fixed label can obscure the tradeoffs being made.