How fast might Dreadnought be with modern propulsion?

What speed might Dreadnought reach with modern machinery using the same weight and space?

The estimate is above 30 knots, while a nuclear-powered version becomes an even more extreme and potentially troubling prospect.

Modern gas turbines could push the historical hull into the thirty-knot range. A later comment notes that one contemporary gas turbine can provide roughly twice Dreadnought's installed power at a tiny fraction of the machinery weight, and the comparison is accepted. A nuclear-propulsion follow-up produces an even stronger warning about the speed such a cruiser-derived hull might reach. The exchange is a thought experiment rather than a structural-performance calculation, but it makes turbine-era power-density limits easy to grasp.