How much engine power would a ship 260 meters long and 26 meters in beam need to exceed 40 knots?
Short answerThe dimensions are insufficient; draft, displacement, hull form, appendages, and water-flow details are needed before power can be estimated responsibly.
NotesA waterline length and beam do not contain enough information to calculate the power needed for more than 40 knots. Draft, displacement, bottom form, keels, skegs, and the shapes of water intakes and outlets all change resistance. Those hydrodynamic details become increasingly important as the target speed rises. A rough comparison with a similarly sized high-powered warship can suggest a value in the hundreds of thousands of shaft horsepower, but it cannot replace the missing hull model. The useful answer is therefore a list of design inputs that must be supplied before an apparently simple speed estimate has meaning.