Town-class cruisers and the design spiral

The Town-class account begins with the Bristol class and the need to meet newer German cruisers. The turbine prototypes Stettin and Dresden, followed by the Kolberg class, could run down British destroyers and threaten colonial trade. They belonged to an escalating chain of cruisers designed to defeat an opponent's previous answer. Initial requirements combined 25-knot speed, twelve 4-inch guns, extra fuel, and protective-deck armour within a nominal 4,000-ton hull. Successively thicker deck schemes raised displacement before the detailed design had settled. Pembroke Dockyard could not dock the enlarged cruiser within the required six months after launch, so one planned ship reverted to a smaller class and the larger vessels went to private yards. Enemy ships shaped the requirements, while the dockyard's physical capacity determined where the resulting design could be built.