Abstract
As the formula of propulsion performance curves, this paper proposes new coefficient (the author calls it New Admiralty Coefficient) which contains four variables ie. the displacement of the ship (Δ) · the speed of the ship (V) · the output of main engine (Ps) · the revolution of propeller (N) .
This New Admiralty Coefficient included logarithmic functions, the idea of which is referred to the report of Mr. Kazuo Ito who worked in Mikado Propeller Corporation. It was confirmed that the error of ship speed based on this coefficient was within 0.82% for 181 vessels.
