What if Britain built five R-class ships as small-tube-boiler Queen Elizabeth-style fast battleships?
Short answer28-knot R-class ships would force Queen Elizabeth upgrades, alter Jutland's battlecruiser fight, and reset British battle-line expectations.
NotesThe answer starts with machinery and armor: if the R class reached about 28 knots, the Royal Navy would have strong reason to rebuild Queen Elizabeth-class ships to match. At Jutland, two fast 15-inch-gun battleships backing the Invincibles could make the German First Scouting Group reconsider its attack and potentially suffer heavier losses. The longer consequence is a British battle line built around 28-knot capital ships, affecting Nelson and Rodney, U.S. comparisons, and treaty leverage.