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GOAL BASEDNEW SHIP CONSTRUCTION
STANDARDS
Dragos RautaINTERTANKO
SAFEDOR 27 January 2005
Germanischer Lloyd, Hamburg
Goal Based StandardsThe IMO adopted principles
• since the flag State has this responsibility throughout the ship’s life, the relevant statutory rules and regulations should include the standards to which the ship is designed and the standards to which the ship is built
• design and building standards should be sufficient to enable a properly maintained ship to continue in service until the end of its economic life
• Goal Based New Ship Construction Standards
Goal Based StandardsINTERTANKO Interpretation
• IMO has recognised the need for statutory regulations for the ship design and for the ship construction phases.
• There are no such statutory regulations.• There are no international standards for the
construction of ships.• There is no unique and well defined standard for
survey of new buildings.• Class develops CSR for some ship types that can be
”accorded” to the GBS principles.
Goal Based Standards INTERTANKO Interpretation
• IMO has also recognised that a ship is reliable and safely serves its purpose only if she is properly operated and properly maintained.
• Operation and maintenance are the main factors that influence the condition of ships after delivery.
• IMO has well defined standard surveys for ships in service.
• IMO has however no standard to ensure that, at the time of delivery the ship is in excellent condition.
Goal Based Standards INTERTANKO Principles
• A ship will be and will stay fit for purpose if:– properly designed– properly constructed– properly operated and– properly maintained
• Therefore, GBS should address all these aspects but, first things first
• Develop international standards where they are lacking: i.e. design and construction
Goal Based StandardsMSC 79 Provisional Agreements
• Developed drafts for– ”basic principles”– ”goals” (Tier I) and– ”functional requirements” (Tier II)
• Draft considered as input for future work
• Initial work plan drafted
Goal Based StandardsDivergent Views
• Wide range of divergent views on:– the methodology used (risk-based; FSA)– draft functional requirements (Tier II) drafted are
not goal based but rather prescriptive– not common understanding of the meaning of GBS– whether to first apply it to oil tankers and bulkers– whether to first address design and construction
and include maintenance and operation on a second phase of development
Goal Based StandardsDivergent Views - Germany
• Evaluate the present safety levels - OK but, for large ships, we know them!
• Procedure for a risk-based evaluation of the current safety levels – ask Class Societies to give up comprehensive incident information!
• Establish future risk acceptance criteria – is already proposed in the draft but contested as being ”prescriptive”
Goal Based StandardsOwner's Experience
• Present Safety Levels (hazard identification)– Perception : accidents happen with elderly &
poorly maintained ships only – WRONG!! i.e. Derbyshire, Amoco Cadiz, Braer, Ievoli Sun, etc.
– Reality: Structural damages in very young ships
– Reality: Major defects in large castings with ships losing steering, power, etc.
Structural damages in young ships
Class NK: Comprehensive damage reviewof 2nd generation of VLCCs, Dec. 1998
Structural damages in young ships
Class NK: Comprehensive damage reviewof 2nd generation of VLCCs, Dec. 1998
DEFECTS ON RUDDER
found few months aftership delivery from Korean yard
Defects in large castings
FILLINGS IN A NEW PROPELLER
found 6 months after ship delivery from Korean yard
Defects in large castings
Goal Based StandardsOwner's Experience
• Present Safety Levels (hazard identification)– Poor design of engine shaft– Structural misalignment– Large tankers and large bulkers with significant restrictions
in cargo operations– Liquid cargo density for calculating sloshing forces
reduced from 1.025 Kg/m3 to 0.9 kg/m3 – there is no rule to stop ships carrying frequently cargoes with densities above 0.9 kg/m3.
– Requirements for ballast water exchange with no guarantee that bending moments would not exceed the maximum allowable
– Asymetric loads during ballast water exchange with torsional stresses unkown and not accounted for
YARD HULL NO. DATEA 5109 1998-08-17B 1089 1998-05-08B 1090 1998-07-03A 5120 1999-01-05A 5121 1999-01-28B 1164 1999-10-26C 1241 1999-12-02C 1241 1999-12-02
The Down Ratchet and the Deterioration of Tanker Newbuilding Standards, Jack Devanney and Mike Kennedy, 2003
KNOWN STERNTUBE BEARING FAILURES ON BRAND-NEW VLCCs OVER 18 MONTHS
Goal Based StandardsOwner's Experience
• Present Safety Levels (hazard identification)– Poor design of engine shaft– Structural misalignement– Large tankers and large bulkers with significant restrictions
in cargo operations– Liquid cargo density for calculating sloshing forces
reduced from 1.025 Kg/m3 to 0.9 kg/m3 – there is no rule to stop ships carrying frequently cargoes with densities above 0.9 kg/m3.
– Requirements for ballast water exchange with no guarantee that bending moments would not exceed the maximum allowable
– Asymetric loads during ballast water exchange with torsional stresses unkown and not accounted for
Goal Based Standards Owner's Experience
• Present Safety Levels (hazard identification)– Mandatory regulations for flooding scenarios which the
ship’s structure will not withstand!– No rule to assess these by FE– FE used for ”optimising” and cutting down strength– VLCCs designed and accepted being ”in class” with a
lightweight below 30,000 tons (normal minimum expected lightweigth is around 35,000 tons and ideal at least 38,000 tons)
– New ships have an unacceptable high residual stress– Lack of corrosion protection, etc.
Pitting as discovered on new double hull tankers (MIC)
Pitting in the tank bottom plate(MIC)
Goal Based StandardsConclusions
• Evaluate the present safety levels – Q.E.D.• Procedure for a risk-based evaluation of the
current safety levels – Which ”current” safety levels – class rules or class approvals of ”optimised” designs?
• Establish future risk acceptance criteria –Owners, the customers of the designers, yards and class have already indicated their expected safety level
Goal Based StandardsConclusions
• However, some Governments want to link the optimum design life of a ship as function of the interest rates at the time of the ship’s construction ?? (MSC 79/6/15)
• Some Governments want to use FSA to establish GBS but FSA is just a tool and not a decision making system. Each time it was used in IMO, FSA process took years and it failed to materialise.
• Allegations that owners wish a ”maintenance free” ship. Although such a thought is not against any risk-based concept, this is a completely non-realistic thought.
Goal Based StandardsOwners/Customers expectations
• GBS is a complex process and needs to be developed in several stages
• First priority: international standards for design and ship construction
• Owners assume responsibility at delivery
• GBS to be set for quality ships at delivery
• Shipyards have to assume responsibility for it over a transition period
Goal Based Standards Owners/Customers expectations
• Cost and Risk Benefit Analysis – irrelevant as long as applying to all new ships
• Large ships – first priority• Life cycle – yes, but when the new buildings’ quality
is defined – (is any intent to a major revision to SOLAS, MARPOL and all other Codes?)
• Other ship types – yes; large ships are the more complex to address, easier to deal with other ships later
Goal Based Standards Owners/Customers expectations
• A fast track development in IMO• Commitment from all Governments• Hazards & problems already defined• They all point to same problem: low quality at the
new builing• No need to re-invent the wheel: improve and apply
current standards as statutory requirements before the ship is delivered
• ACT NOW! Before a new generation of tankers is already built
