Queen Mary followed the Lions with slightly better armour and a quoted 28-knot top speed while retaining 70,000 shaft horsepower. Britain was launching roughly one battlecruiser a year and could modify the next design as requirements changed. Germany's practice of ordering in tranches made that continuing adjustment harder. Queen Mary's three differently shaped funnels also illustrate contemporary attempts to improve the handling of boiler exhaust.
Notable Point · 55:51-57:24
Queen Mary and annual design improvements
Annual British battlecruiser construction allowed successive design improvements, putting pressure on Germany's more rigid ordering system.