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Common Structural Rules for Tankers Gary Horn, P.E. Director, Technology ABS Houston. Houston Tanker Event 2007 Houston, TX 26 March 2007. IACS Common Structural Rules. AIM:
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Common Structural Rules for Tankers Gary Horn, P.E. Director, Technology ABS Houston Houston Tanker Event 2007 Houston, TX 26 March 2007
IACS Common Structural Rules AIM: To develop a set of unified Rules and Procedures for the determination of the structural requirements for oil tankers and bulk carriers
Tanker Operations Tanker incidents by cause 1978-2004 Source: Intertanko
Tanker Operations • Improvements made in tanker operational, safety and pollution performances • We have “come a long way…” • However, we wanted to employ continuous improvement principles and take the next step… Common Structural Rules intended to enhance safety, robustness and durability.
IACS Common Structural Rules • CSR for Tankers • Complete Set of Structural Rules for Double Hull Oil Tankers • Length greater than or equal to 150m • CSR for Bulk Carriers • Complete set of Structural Rules for SSS and DSS Bulk Carriers • Length greater than or equal to 90m
Features of the new CSR • Rules are to result in common scantling requirements • Net scantling approach includes a clear link between newbuilding strength checks and in-service gauging review standards • Include coating standard criteria • Fatigue standard enhanced to include exposure to North Atlantic environment with minimum life of 25 years • Includes the results from industry input and feedback
IACS Common Structural Rules • Tankers Hull Girder Ultimate Strength Structural Strength Assessment Fatigue Strength Assessment Buckling Strength Assessment
CSR/Tanker - Overview Loads Design Require-ments General Rule Require-ments Scantling Requirements Minimum Require-ments Design Verification
CSR & Coating Performance Standards Protective Coating Wastage Allowance Predicted corrosion in 2.5 years (0.5 mm) Required Renewal Thickness Annual Thickness Measurements • Promote effective use of protective coatings • Provide a protective barrier to delay onset of corrosion, noting; • Corrosion wastage allowance is still included in rules • Wastage allowances are not reduced due to presence of coatings • Target useful coating life of 15 years • Added benefit – facilitate in-service inspection • Top coat to be a light color to easily distinguish from rust
Coating Performance Standards IMO Res MSC.215(82) Performance Standard for Protective Coatings for Dedicated Seawater Ballast Tanks in All Types of Ships and Double-Side Skin Spaces of Bulk Carriers IACS PR No. 34, IACS Procedural Requirement on Application of the IMO PSPC under IACS Common Structural Rules for Bulk Carriers and Oil Tankers IACS Common Interpretation and answers to frequently asked questions on IACS website www.iacs.org.uk ABS Guide for the Class Notation Coating Performance Standard (CPS), December 2006
CSR Rule Status • CSR - effective date 1 April 2006 • Tanker updates: • Corrigenda 1 – effective date 1 April 2006 • Corrigenda 2 – effective date 1 April 2006 • Rule Change Notice (RCN) No. 1 – effective date 1 April 07 or earlier if agreed between yard and owner • All future updates to follow IACS process: • PR32 • Hull Panel • Project Teams • Rule updates and maintenance • Rule interpretations, Q/A
CST/Tanker RCN No.1 • Effective 1 April 2007, may be applied earlier if agreed by builder and owner. • Can not be partially applied • Contents: • Corrosion additions for heated cargo tanks • Clarification of heavy ballast condition • Buckling assessment in way of bottom portion • FE analysis of tight floor, girders and webs • Slenderness ratio of bulb profiles • Deck equipment welding • Tolerance of hopper knuckle connection
Oil Tanker Orders - Gross Tons Source of feedback…
Oil Tanker Orders – Number of orders Source of feedback…
IACS Project Teams for CSR Maintenance • IACS implemented 2 Project Teams for CSR Maintenance • Active from 1st June 2006 • PT for Bulk Carriers: 3 JBP + 1 JTP members • PT for Oil Tankers: 3 JTP + 1 JBP members • Rotation among members every 2 years • Running of the PT governed by IACS procedure
IACS CSR Knowledge Center/Database • Centralized mechanism for collecting, categorizing and storing questions and answers, feedback and responses, tasks and pending actions, interpretations and rule changes • Basis for future improvements • External access to Q&A and Interpretations from IACS Web Site Transparency and consistent implementation of the Rules
GBS Overview IMO • Basic Principles of Goal-Based Standards • Broad, over-arching safety, environmental and/or security standards that ships are required to meet during their lifecycle • The required level to be achieved by the requirements applied by Class Societies and other ROs, Administrations and IMO • Clear demonstratable, verifiable, long standing, implementable and achievable irrespective of ship design and technology; and • Specific enough in order not to be open to differing interpretations
GBS Overview Tier I IMO Tier II IMO Functional Requirements Tier III IMO Goals Verification and Acceptance criteria Tier IV IACS Tier V Industry Procedures and Quality Systems Requirements, Rules and Industry Standards IMO IACS CSR for Oil Tankers & Bulk Carriers
Influence of GBS on future CSR developments • Structural residual strength: the CSR partially cover the GBS intent, but additional work necessary to define assumed extent of structural damage, environmental loads and acceptance criteria • Structural redundancy:the CSR partially cover the GBS intent, but additional work necessary to develop method to confirm structural redundancy and structural hierarchy • Reference to other standards:cross reference other regulations or standards • Human element • Design transparency • Survey and maintenance • Structural accessibility • Recycling considerations
Why Common Structural Rules? An improved structural standard. A major aspect in a complex yet integrated set of initiatives with the goal of improving performance for the safety of life, property and the marine environment.
Thank you Common Structural Rules for Tankers Gary Horn, P.E. Director, Technology ABS Houston