Why are HMS Belfast and HMS Edinburgh not counted as a two-ship class?
Short answerBecause they are a modified continuation within the larger Town-class cruiser programme, not an independent pair.
NotesA two-hull construction batch is not automatically a separate class. Belfast and Edinburgh belong to the continuing Town-class design lineage, even though they form a modified final group. They differ from two ships conceived as a self-contained class with no larger production sequence around them. The distinction gives viewers a practical test for separating a subclass or batch from a genuinely independent pair of sisters.