Section 7 Rudder skegs and rudders
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Special Service Craft, July 2022 - Part 4 Additional Requirements for Yachts - Chapter 3 Special Considerations for Sailing Yachts - Section 7 Rudder skegs and rudders

Section 7 Rudder skegs and rudders

7.1 Skegs

7.1.1 Skegs are to be effectively integrated into the adjacent structure and their design is to be such as to facilitate this.

7.1.2 The scantlings of skegs are to be sufficient to withstand any docking forces that they may be subjected to.

7.1.3 The thickness of the skeg plating is in no case to be taken as less than 1,5 times the thickness of the adjacent bottom shell or the fin and tuck laminate whichever is the greater.

7.1.4 Where metallic sub-frames are laminated into skegs, providing transverse stiffening to the skeg and support for the rudder pintle, such stiffening members are to be fully integrated with hull framing to ensure continuity of strength.

7.1.5 The scantlings of skegs of composite construction will be specially considered on the basis of the Rules, and in this respect are to be of equivalent strength and load carrying capability to that required for skegs of steel construction from Pt 3, Ch 3, 3.3 Rudder horns. Due account is to be taken of the differing material properties.

7.1.6 Direct calculations may be used as an alternative to the requirements of Pt 4, Ch 3, 7.1 Skegs 7.1.5 to determine the scantlings of composite skegs. Such calculations are to be submitted for appraisal.

7.2 Rudder construction arrangements

7.2.1 Rudder construction for sailing yachts is generally to be in accordance with Pt 3, Ch 3, 2 Rudders.

7.2.2 For use in the determination of the rudder stock diameter, within Table 3.2.6 Rudder stock diameter, the factor f c may be taken as 70 for yachts with an overall length, L OA, of 24 m varying up to 79 at a length of 50 m. Intermediate values are to be determined by linear interpolation. Yachts with a length, L R, in excess of 50 m are to comply with Table 3.2.6 Rudder stock diameter.

7.2.3 The rudder stock diameter is to be based upon the maximum stated operational speed of the yacht, but in no case is this to be taken less than knots. L WL is as defined in Pt 3, Ch 1, 6.2 Principal particulars 6.2.5.


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