Section 5 Rudder Stocks

501. Upper stocks

The upper stock diameter ᾘῌ required for the transmission of the rudder torque is to be determined so that the torsional stress not exceed 68/Åᾯ NNÕmm ĪŃ . The dimensions of the upper stock diameter may be determined by the following formula.

ᾘ ĨĮΡ̓Į DÜÅ

ῌ Ņ Ĉ Ċ

Nmm Ń

DĈ : as defined in 301.

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

502. Lower stocks

If the lower stock is subjected to combined torque and bending, the equivalent stress in the lower stock is not to exceed 118 / Ks (N/mm2).

ſſ Ņ

Ρ̓Üſſ Ī Ñ Į ſſi Ī

NNÕmm ĪŃ

ᾙ ᾎ ᾼ

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

ÌLǾĪB Į

ſſᾎ Ņ ÜĮ

ᾘᾨ

× ÌL

NNÕmm Ń

JǾÌDĈ Į

ſſiᾼ Ņ ÜĮ

ᾘᾨ

× ÌL NNÕmm Ń

Pt 4 Hull Equipment

Ch 1 Rudders Pt 4, Ch 1

: 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.