Tiger was laid down in June 1912, five months after the decision to develop the 15-inch/42 gun. Her large barbettes make substituting that battery a fiddly change, but it is judged feasible without a fundamental redesign. The gun was test-fired in May 1914, and Queen Elizabeth commissioned only about two months after Tiger, illustrating the overlap between the programs. A 15-inch Tiger would probably be slightly longer and better armored while retaining a proposed speed of 28 knots or more. With Australia and New Zealand added to the Lion sequence, Tiger would be the sixth battlecruiser in that progression, following five 13.5-inch ships. That is the point at which the counterfactual predicts a change to 15-inch guns.
Notable Point · 58:18-1:00:43
Why Tiger could become the first 15-inch battlecruiser
Tiger's construction schedule and large barbettes make a 15-inch battery plausible as the next step after five 13.5-inch battlecruisers.