Section 18 Fatigue
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 10 Ship Units - Chapter 1 General Requirements - Section 18 Fatigue

Section 18 Fatigue

Parent topic: Chapter 1 General Requirements

18.1 General

18.1.1 The fatigue life is to be assessed in accordance with the LR ShipRight Procedure for Ship Units and Pt 4, Ch 5, 5 Fatigue design.

18.2 Factors of safety on fatigue life

18.2.1 The factors of safety defined in Pt 4, Ch 5, 5.6 Factors of safety on fatigue life are to be applied to the hull structure. Examples are given in Table 1.18.1 Example factors of safety on fatigue life for hull structure.

Table 1.18.1 Example factors of safety on fatigue life for hull structure

Location Inspectable/repairable? Substantial consequence of failure? Fatigue life factor
Bilge keel in way of ballast tanks or void spaces

Wet

(OIWS)

No

(no pollution)

 2
Bilge keel

Wet

(OIWS)

Yes

(pollution)

 4
LNG pump tower attachment points (top dome penetrations and bottom base support penetrations)

No

(covered by insulation)

Yes

(loss of primary and secondary barriers)

 10
LNG pump tower Dry

Yes

(loss of primary and secondary barriers)

 2
Bottom longitudinal stiffener end connections inway of ballast tanks or void spaces Dry

No

(no pollution) 		1
Bottom longitudinal stiffener end connections Dry

Yes

(pollution)

 2
Double hull hopper knuckle connection Dry

No

(no pollution)

 1
Stiffened plate module supports attachment to upper deck Dry No 1
Lattice module supports attachment to upper deck Dry Yes 2
Lattice module supports attachment to upper deckwith single member redundancy Dry No 1
Hull structure bounding membrane LNG tanks

Equivalent to wet

(repair will damage insulation)

 No 2
Penetrations in upper deck for LNG tank domes

No

(covered by seal)

 No 3
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