At the Marine Engineering Committee of the Kansai Society of Naval Architects the designing method of a marine propeller and shafting is now under consideration, and on the key fixing the propeller upon the propeller shaft its standard dimension sand the method of calculating its strength have been determined. We are going t oreport the decision on behalf of the committee. The formulas calculating its stresses are as follows. [numerical formula], [numerical formula] where T = torque of the engine at M.C.R. (kg-m) D_m = mean diameter of the propeller shaft in the cone port (m) D_c = D_m - (H_c)/(100) (m) L_a = effective length of the key (cm) B = width of the key (cm) H_c = effective depth of the key way (cm) τ = shearing stress of the key (kg/cm^2) σ = compressive stress of the key (kg/cm^2) The allowable values are τ = 400 kg/cm^2 and σ = 1500 kg/cm^2.
