Royal Arthur, Crescent, and variation within a cruiser class

Royal Arthur and Crescent replaced the forward 9.2-inch weapon with two additional 6-inch guns and are often treated as a subclass. Yet the wider class already contained engines supplied by several manufacturers, including Maudslay, Napier, Humphrys, Penn, and Earle. Those machinery differences complicate any simple boundary between the modified pair and their sisters. Late nineteenth-century class identity could coexist with substantial construction and equipment variation.