How fast could a turbine-powered Renown actually go?

Would Renown's hull prevent the large speed increase proposed for a gas-turbine reconstruction?

The hull still limits the gain, but its efficient form could plausibly support about thirty-six to thirty-eight knots with enough power.

Additional shaft horsepower does not translate directly into the same percentage increase in speed. Renown's long battlecruiser hull is efficient, and simulations suggest that enough power might drive it toward forty knots, but that would not be a comfortable operating condition. Roughly thirty-six to thirty-eight knots is the more credible range for the counterfactual reconstruction. The exchange keeps hydrodynamic limits in view when evaluating a lighter and more powerful propulsion plant.