Section 5 Rudder Stocks

501. Upper stocks

The upper stock diameter required for the transmission of the rudder torque is to be so that the torsional stress not exceed 68/ N mm . The dimensions of the upper stock diameter

mm

: as defined in 301.

: material factor for rudder stock, as given in 102.

502. Lower stocks

The diameter of the lower stock subjected to combined forces of torque and bending moment is to be determined so that the equivalent stress in the rudder stock not exceed 118/ N mm .

The

equivalent stress is to be obtained from the following

N mm

and : the bending stress and torsional stress acting on the lower stock, determined as follows respectively.

× N mm

× N mm

: bending moment(N m ) at the section of the rudder stock considered.

as defined in 301.

When the horizontal section of the lower stock forms a circle, the lower stock diameter may be determined by the following formula.

mm

: upper stock diameter(mm ) as given in 501.