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Presentation on theme: "GBS PILOT PROJECT ROUND TABLE REVIEW TRIPARTITE TOKYO 20th SEPTEMBER 2007."— Presentation transcript:


2 Pilot Panel (PP) requested to produce the following to MSC 83: Procedures for carrying out the verification process (Tier III) Information and documentation needed Evaluation criteria to be used by the Group of Experts Potential modifications of Tiers I & II Reporting format that should be used

3 Regulation verification IACS prepared a comprehensive report titled “IACS Documentation Package for the IMO GBS Pilot Project” The demonstration package addressed IACS CSR for DH oil tankers Note: Verification of CSR was not within the scope of the PP but a simulation IACS provided a detailed presentation on CSR tankers to the PP.

4 Guidelines Verification of compliance with GBS Part A, Tier III verification process: –a Tier III Verification process –verify that ship construction rules (Tier IV) satisfy the GBS as listed in Tier II Part B, Information / documentation requirements and evaluation criteria –PP developed a statement of intent for each of the Tier III requirements that Rules owner follows when submitting information, documentation and evaluation criteria to the Group of Experts.

5 Specific Areas Considered III.1Design Life III.2Environmental Conditions Source of sea state data North Atlantic environmental conditions III.3Structural Strength Designed to withstand at net scantlings the operational and environmental loads III.4Fatigue Life III.5Residual Strength Survivability: collision, grounding and flooding Relationship of the flooding scenarios to IMO instruments Consensus that there is insufficient information currently available to develop specific evaluation criteria for residual strength. Submitter to demonstrate, through the analysis of representative designs, that their Rules require a reasonable level of residual strength after damage considering existing IMO requirements, the application of the extents of damage and associated environmental conditions of existing IMO requirements. Note: IMO damage stability cases! Also, weather conditions!

6 Specific Areas Considered III.6 Protection Against Corrosion III.6.1 Coating Life: Confirm that the coatings are properly selected and applied to protect the structure for the target useful life (i.e. IMO PSPC). III.6.2 Corrosion Addition: Confirm that the Rules for corrosion additional values are rationally based and adequate for the specific design life III.7 Structural Redundancy: Sufficient redundancy to withstand localized damage in any other stiffening structural member III.8 Watertight and Weather tight Integrity III.9 Human Element Considerations III.10 Design Transparency III.11 Construction Quality Procedures

7 Detailed Evaluation Criteria for Rule Maintenance Ensure consistent and repeatable verification over time for different rule submissions and evaluators Relevant information and documentation requirements Will be most effective if a transparent process for continuous performance monitoring is established which requires a RO to perform a continuous self-assessment of the effectiveness of Rules and report back to the IMO on a regular basis, a feed-back loop for Rule performance.

8 Maintenance of Verification On an annual basis by each RO Make available proposed rules changes to all Administrations by whom RO is recognized Should clearly indicate why those changes will not affect the compliance with GBS Administration considers that changes in the Rules of a RO could lead to non-compliance with GBS, it may request the Secretary-General to conduct a review Every five years shall submit a report to the Secretary through their sponsoring Administration that describes the changes that have been made during that period

9 Group of Experts Independent panel of technical experts whose decisions are not affiliated with any member state or organization Shall consist of [7][9][11] members Three will serve for terms lasting 3 years Staggered by a year each; shall not serve successive 3 year terms; the remainder shall serve on an ad hoc basis A [simple]/[two-thirds] majority will be required for all findings Selected from a list of experts maintained by the IMO S.G. Administrations or non-governmental organizations with nominate individuals for inclusion on the list of experts Selection by qualifications to ensure appropriate representation and expertise for the specific rules being considered IMO S.G. shall identify a chairman responsible for overall coordination. IMO S.G. will provide the Group with adequate administrative assistance, including a permanent secretary

10 Net scantlings PP could not come to agreement as to how to apply the definition of the net scantling One interpretation is that there should be the same net scantling to be used for all structural calculations (local and global structural responses) However, there is no reference or clarification on this issue with regard to fatigue assessment IACS CSR for tankers apply a different approach for determining nominal design scantlings for each of the strength modes being evaluated, i.e. local, hull girder and fatigue strength.

11 Difference 1: - Local strength/steel renewal is calculate for the NET scantling value (red line) - - Hull girder strength evaluted to the 10 % diminution in hull girder section modulus (approach as per SOLAS requirements)

12 Difference 2: Fatigue calculation for BULK CARRIERS assumes thicknes = net + 50% of the corrosion allowance intact

13 Difference 3: Fatigue calculation for OIL TANKERS assumes thicknes = net + 75% of the corrosion allowance intact

14 Net scantlings A majority of the PP members felt that the application of a “single” or “pure” net scantlings for all structural calculations is too simplistic, not allowing for the efficient optimization of structure. Other members felt that the definition of net scantlings as defied in Tier II.3 should be used throughout Tier III because it is transparent, simple, and easy to apply and monitor. It will provide future members of the Group of Experts with a simple approach, which can be readily checked. In the absence of any justification and benchmarking of different approaches, it is presently the only possible option that should be used from a purely scientific point of view to fulfill Tier I goals. Therefore, the current Tier II footnoted definition shall remain as is, and that assumed loads, safety factors and acceptance criteria shall be adjusted as needed within the scope of Tier I goals.

15 Net scantlings PP agreed that the appropriate thickness to be applied in scantlings assessment must be considered in conjunction with other factors, such as extreme loads, safety factors and acceptance criteria, and that all methods should be appropriately justified and benchmarked with service history.

16 Recommendations for Future Work Guidelines should undergo additional refinement and development through a second, more detailed trial application with CSR There was not a consolidated version of the Tier III verification process available to allow IACS and the PP to conduct a proper trial application. PP spent the majority of the available timeframe developing the Guidelines, and there was no time to test them against CSR bulk carriers.


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