Tiger as a small-tube boiler test bed

If Tiger had served as a small-tube boiler test bed, could she have reached 30 knots?

Probably. The answer projects roughly 30 knots for Tiger and later battlecruisers, about 26 to 27 knots or slightly more for the Queen Elizabeths, and around 27 knots for the R class.

Fitting Tiger with small-tube boilers could plausibly have made her a 30-knot test bed. Successful machinery might then have been adopted in the Queen Elizabeth class, for which about 26 to 27 knots, perhaps slightly more, is suggested. The projection gives later battlecruisers speeds around 30 knots and battleships around 27 knots. The R class might follow the same machinery path. In this counterfactual, the Royal Navy could build a substantially faster battle line.