Section 5 Ship structures: approval
Clasification Society 2024 - Version 9.40
Clasifications Register Guidance Information - Guidance Notes for Air Lubrication System Guidance Notes, January 2020 - Chapter 1 Air Lubrication System Guidance Notes - Section 5 Ship structures: approval

Section 5 Ship structures: approval

Parent topic: Chapter 1 Air Lubrication System Guidance Notes

5.1 General

5.1.1 The ALS structural design shall be evaluated depending on the system architecture, ship type and operational profile.

5.2 Design considerations

5.2.1 Global Hull Strength - the size and location of the ADU may directly affect the global strength. This should be determined using the appropriate means and actioned accordingly. The global strength assessment should be revised, if applicable, where the original Assessment by Direct Calculation, Structural Design Assessment (SDA) or (if required) Fatigue Design Assessment (FDA) has been meaningfully deviated from.

5.2.2 Local Hull Strength - tertiary hull loads, strength and bending should be appropriately considered when designing the ALS hull stiffeners, girders and beams, with maximum stress continuity to be achieved. The detailed design should appreciate the limited access, fit up requirements, weld sequencing and weld procedures. The ADU shall be regarded as shell plating, and as such the material and thickness shall be equivalent.

5.2.3 Dynamic Loading – increased dynamic forces attributed to slamming in adverse weather shall be considered and appropriately accounted for. The requirements are ship-type dependent and shall be applied accordingly.

5.2.4 Maximum Ship Speed – rudder installations are designed for the maximum ship speed at the summer Loadline mark at maximum propeller RPM and corresponding MCR. Attention to this specified speed should be respected or the appropriate action taken.

5.3 Applicable Rules

5.3.1 The following are applicable from Rules and Regulations for the Classification of Ships, July 2022:
5.3.2 The following are applicable from ShipRight Procedures:
  • ClassDirect, ShipRight Procedures, Design and Construction, Structural Design Assessment;
  • ClassDirect, ShipRight Procedures, Design and Construction, Fatigue Design Assessment.

5.4 Required submissions

5.4.1 Submissions shall include:
  • General Arrangement (GA) of ALS (vessel specific);
  • ALS hull penetration details: locations on the Shell Expansion drawing, transversal sections and longitudinal sections of area;
  • Welding details;
  • Detailed Structural drawings where the ADUs are intended to be installed;
  • Information relating to any limitations of the vessel (service restrictions or other); and
  • Docking plan showing positions of ADUs (for information).

5.5 Deliverables

5.5.1 If considered necessary, a Design Appraisal Document (DAD) shall be issued at the end of the design appraisal process.

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