Section 4 Fatigue design assessment
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Ships, July 2022 - Part 3 Ship Structures (General) - Chapter 16 ShipRight Procedures for the Design, Construction and Lifetime Care of Ships - Section 4 Fatigue design assessment

Section 4 Fatigue design assessment

4.1 Fatigue Design Assessment notations – FDA, FDA plus, and FDA ICE and FDA SPR

4.1.1 Where specified in the Rules the fatigue performance of the hull structure is to be assessed in accordance with the applicable ShipRight FDA procedures. Where an appraisal has been made whether on a voluntary or mandatory basis of the fatigue performance of the hull structure in accordance with the relevant procedures and found to comply with the requirement of 20 years fatigue life based on the 100A1 Fatigue Wave Environment (World-wide) trading pattern the ShipRight notation FDA will be assigned, see also Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.17. In general the ShipRight FDA procedure is mandatory for all bulk carriers and oil tankers without a CSR notation and of length greater than 190 m or where the type, size and structural configuration demand. The ShipRight notation FDA is not applicable to ships approved using the IACS Common Structural Rules.

4.1.2 Where an appraisal is requested for a higher level of fatigue performance of the hull structure than that made for the assignment of the ShipRight notation FDA, the relevant procedures for the application of the ShipRight notation FDA plus() are to be applied. The appraisal may be made based upon a specific trading pattern, which is to be expressed in terms of either a Worldwide trading route, as defined in the relevant ShipRight procedures, or a North Atlantic trading route (that utilises the wave data from IACS Recommendation 34). The ShipRight notation FDA plus() is to be followed by the number of years that the vessel has been assessed for the specific trading pattern shown in brackets, for either the Worldwide or North Atlantic trading routes, denoted by WW and NA respectively, e.g. FDA plus(25, NA). This procedure is applicable to all ships including those built in accordance with the IACS Common Structural rules.

4.1.3 Where an appraisal is requested for the fatigue performance of the hull structure when navigating through ice, the relevant ShipRight FDA ICE procedures are to be applied. Where the relevant procedures have been applied the ShipRight notation FDA ICE will be assigned, see also Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.17.

4.1.4 Where specified in the Rules an appraisal is to be made of the fatigue performance of the hull structure taking into account of the effects due to the continuous vibrational response of the hull girder in waves (springing) in accordance with the relevant ShipRight procedures. Where the relevant procedures have been applied the ShipRight notation FDA SPR will be assigned, see also Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.17.


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