Design Speed at www.japanese-home-gardens.com

The coefficient in the above equation for metric (inch) units may be reduced from 21.66 (0.26) to 19.2 (0.23) where the design speed is 17 or more knots; intermediate coefficients may be used where the design speed is between 11 and 17 knots. Where rudders are of streamlined shape the coefficient in the above equation may be taken as 19.2 (0.23), but the minimum design speed to be used is 13.2 knots.

The coefficient in the above equation for metric (inch) units may be reduced from 21.66 (0.26) to 19.2 (0.23) where the design speed is 17 or more knots; intermediate coefficients may be used where the design speed is between 11 and 17 knots. The lower stock is to be of the full diameter to the top of the rudder, below this the requirements for strength of rudder in 5.9.1 apply. The bearing is to be bushed and the bushing effectively secured against movement.

Given the hull, the remaining problem is propulsion. A certain model of hull will found to have a definite economic speed. At this speed the engines labor without correspc ing effect. This economic speed can be ca lated very closely by the shipbuilder from under-water lines of his design and checked towing a model in a towing tank. He is 1 able to decide upon the size of the propeller propellers needed—their diameter and pitch, the number of revolutions they must make minute to drive the ship at the desired rate.