Section 2 Rudder Force

201. Rudder force

1. The rudder force upon which the rudder scantlings are based is obtained from the following formula.

mean height of that part of the rudder which is situated abaft the centre line of the rudder stock

total area of rudder

: maximum service speed. However, if the maximum output of the propelling machinery ex- ceeds the normal output which corresponds to the contracted speed by 15 % or more, is to be increased by the percentage in Table 4.1.3.

Table 4.1.3 Increase Percentage (%)

2. For rudders which at no angle of helm work in the slipstream behind a propeller, the rudder force may be taken as 80 % of that obtained from the formula in Par 1.

Pt 4 Hull Equipment

Ch 1 Rudders Pt 4, Ch 1