Take a 375-ton catamaran, powered by 30 MW of hydrojets. The engines give 300 tons of motive thrust.
With no hydrodynamics, the drag is 6,879 and the speed is 26.6 * 2 (planing) * 1.1 (streamlining) = 58.5 mph. With mediocre lines, the drag is 1376 and the speed is 45.5 * 2 (planing) * 1.1 (streamlining) = 100 mph. With average lines, the drag is 688 and the speed is 57.3 * 2 (planing) * 1.1 (streamlining) = 126 mph. With fine lines, the drag is 457 and the speed is 67.7 * 1.1 (streamlining) = 72.3 mph. With very fine lines, the drag is 344 and the speed is 72.2 * 1.1 (streamlining) = 79.4 mph. So in order of efficiency the lines are average, mediocre, very fine, fine and none. While it makes sense that a planing hull might beat a displacement hull, it seems a bit odd. Comments? _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
