The extra Dominion batch could make Queen Mary resemble the historical Tiger, leaving Tiger herself another opportunity to change. A 15-inch/42 gun is the proposed next step. Development was authorised in January 1912, before Tiger was laid down in June, although her original order preceded that decision. The gun's May 1914 test firing and the October and December commissioning dates quoted for Tiger and Queen Elizabeth make the schedule plausible in this scenario. A 13.5-inch gun could serve as a fallback in the larger turret. If Tiger introduced the weapon first, Queen Elizabeth could treat small-tube boilers as its next major innovation and aim for about 28 knots. Tiger could still retain 13.5-inch guns, so the faster-battleship consequence depends on choosing the larger weapon.
Chapter · 1:18:21-1:27:14
A 15-inch Tiger and fast-battleship convergence
Earlier design evolution makes Tiger a plausible first 15-inch ship and leaves small-tube boilers and greater speed as Queen Elizabeth's major new features.