Please don't knock this down without solid reasoning... i have no background in ship design, and im curious. 1. What is the benefit of having destroyers and frigates as different classes of ship? Is it not possible to have the weapons and sensor systems integrated on the one (possibly slightly larger) hull, saving significantly on cost and manpower? Destroyer with towed array and harpoons: ASW helo and seafox 2. What dictates the hull size of a destroyer or other non-capital ship? Could modern weapons systems (say PAAMS consisting of the silos, sampson radar, chilled water and Command and control computing racks) not be packed onto a hull the size of a minesweeper? 3. Further to two - if a platform could operate with no manpower (think UAV on the sea) could the idea of no.2 be achieved, since there would be no "life support" need.