Steam frigates bridge wooden walls and HMS Warrior

Did HMS Warrior sail alongside ships of the line, or was she intended to replace them?

Ships of the line and steam frigates still served when Warrior appeared, and she initially looked like a much larger, more powerful steam frigate rather than an entirely separate category.

Ships of the line and steam frigates still served when HMS Warrior appeared, with some older ships already converted to auxiliary steam power. Warrior can therefore be understood as an enlarged and much more powerful steam frigate: her guns remained on one deck, but they were heavier than the rating label might suggest. That arrangement explains why she was initially rated as a frigate even though later naval history treats her as a battleship ancestor. The wooden battle line gave way to the ironclad through a period of overlap.