Speed relative to contemporary battleships is the defining problem for a late battlecruiser. A late-war design must reach roughly 36 knots or more to preserve a meaningful margin over 28-30-knot fast battleships. It also needs 15- or 16-inch guns because a ship that cannot avoid every capital-ship encounter must carry credible firepower when forced to fight. Earlier British, Japanese, and American battlecruisers generally shared the main-gun calibre of their contemporary battleships, from 12- and 13.5-inch designs through Kongo and Lexington. German or Soviet exceptions reveal industrial constraints and attempts to force requirements into an inadequate production base rather than a separate universal rule. By the end of the Second World War, these demands make a new battlecruiser converge on an exceptionally long and fast battleship.
Notable Point · 3:34:29-3:39:09
Why a late battlecruiser needs speed and battleship guns
Once fast battleships make 28-30 knots, a distinct battlecruiser must reach roughly 36 knots while retaining the main guns of its battleship generation.