Treat power architecture as a combat requirement

Selecting a hull before its power supply risks leaving too little generation for the chosen weapons or forcing a redesign. The Type 45 example contrasts later diesel upgrades with an earlier proposal for three gas turbines and three diesel generators. The proposed margin would have allowed one turbine and one diesel to undergo maintenance underway while retaining adequate power. Generation choices include diesel and gas machinery, with a further distinction between direct drive and integrated electric propulsion. Continuous demand and short combat surges need separate consideration. The design must also supply propulsion, allow for future demand beyond the original budget, and retain enough redundancy for a warship exposed to damage. Errors in generation or distribution can undermine the ship's combat capability.