How the larger Edinburgh group matched Town-class speed

How could the heavier Edinburgh subclass be rated for similar speed with less stated power?

Its longer, more efficient hull converted power into speed differently, while hull form, propellers, boilers, and conservative published ratings complicated simple comparisons.

The Edinburgh group's greater length helps explain its apparently contradictory speed and power figures. Hull form determines how effectively machinery power becomes speed, so displacement and shaft horsepower cannot be read in isolation. Propeller design, cavitation, evolving boilers, and the exact shape of each hull also affected performance across the class. Published top speeds deserve caution because declared figures often conceal the difference between design ratings and what ships achieved in service.