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Project POP&C (Pollution Prevention & Control) A Rational Risk Based Approach For Design And Operation Of Tankers. By Dr Seref AKSU Department of Naval Architecture & Marine Engineering, Universities of Glasgow and Strathclyde. International Workshop on Marine Pollution Control, - PowerPoint PPT Presentation
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Project POP&C (Pollution Prevention & Control)A Rational Risk Based Approach For Design And
Operation Of Tankers
International Workshop on Marine Pollution Control,
Athens , 9 June 2006
By
Dr Seref AKSU
Department of Naval Architecture & Marine Engineering,
Universities of Glasgow and Strathclyde
Presentation Outline
• Background
• Project Pollution Prevention and Control
Objectives
Technical Work Areas
Some findings / Expected Outcomes / Dissemination Activities
• Concluding Remarks
Background to Tanker Safety
Stricter International Regulations enacted in the early 90s, improved the tanker industry safety record but societal concern is ever present.
Despite these efforts, tanker accidents continue to occur
Erika and Prestige incidents have had major political, social and economical implications. As a result, new accelerated phase-out of single hull tankers was introduced.
Despite the political and economic importance of these issues, some of the relevant new regulation still tends to be made before incidents have been properly investigated.
A proper risk analysis may determine which types of oil tanker pose the highest pollution risk, the relative safety of new tanker designs, or the most appropriate response to an evolving oil pollution incident.
Pollution Prevention and Control - POP&C Project
FP6 - Strategic Targeted Research Project (STREP)Start date : January 2004Duration : 3 yearsTotal Budget : 2.2 mEuros
Consortium consists of
4 Universities 5 Research Institutions2 Classification Societies2 Ship yards2 Ship Operators, and
IMO (External)
Consortium PartnersParticipant name Short name Country
INTERTANKO INTERTANKO Norway, UKUniversity of Strathclyde NAME-SSRC UKBureau Veritas BV FranceSirehna SIREHNA FranceCenter of Maritime Technologies CMT GermanyNational Tech. Univ. of Athens NTUA GreeceGdynia Shipyard GDY PolandMaritime Simulation Rotterdam MSR NetherlandsLloyd’s Register lloyd’s Register UKNavantia NAV SpainSSPA Sweden AB SSPA SwedenIstanbul Technical University ITU TurkeyHerbert Software Solutions - EU HSSE UKSouter Shipping (OSG) OSG UKUniv. of Newcastle Upon Tyne UNEW UK
POP&C Objectives
• To develop a risk-based methodology to assess the oil spill potential of tankers
• To develop a risk-based passive pollution prevention methodology (design and operational lines of defence)
• To develop a risk-based active post-accident pollution mitigation and control framework
POP&C
WP6
Pollution Prevention
Environmental Impact Assessment
WP7
Pollution Mitigation and Control
Environmental Impact Assessment
WP5WP3
WP4
WP2
FIRE/ EXPLOSIONpf1
COLLISION/
GROUNDINGpf2
STRUCTURAL FAILURE
pf3
LOSS OF DAMAGE STABILITY/
SINKAGE Pfd
LOSS OF STRUCTURAL
INTEGRITY Pfs
OIL OUTFLOW-Co
LOSS OF VESSEL-Cp
DEATH/INJURY - Cl
Calibration of Probabilistic Index-A
using pertinent scenarios to match
historical risk
Formalised Risk Assessment or Risk-Based Design of Tankers
Risk = Σw.Pfi x Σw.Ci.Rf
PASSIVE SAFETY ACTIVE SAFETY
RISK REDUCTION MEASURES/ INCIDENT
MANAGEMENT Rf
LO
SS O
F W
AT
ER
TIG
HT
IN
TE
GR
ITY
HA
ZID
(T
anke
r D
atab
ase)
Calibration of Pf through pertinent
scenarios, using structural reliability, to match historical risk
STAY AFLOAT Pfi
WP6
Pollution Prevention
Environmental Impact Assessment
WP7
Pollution Mitigation and Control
Environmental Impact Assessment
WP5WP3
WP4
WP2
FIRE/ EXPLOSIONpf1
COLLISION/
GROUNDINGpf2
STRUCTURAL FAILURE
pf3
FIRE/ EXPLOSIONpf1
COLLISION/
GROUNDINGpf2
STRUCTURAL FAILURE
pf3
LOSS OF DAMAGE STABILITY/
SINKAGE Pfd
LOSS OF STRUCTURAL
INTEGRITY Pfs
OIL OUTFLOW-Co
LOSS OF VESSEL-Cp
DEATH/INJURY - Cl
Calibration of Probabilistic Index-A
using pertinent scenarios to match
historical risk
Formalised Risk Assessment or Risk-Based Design of Tankers
Risk = Σw.Pfi x Σw.Ci.Rf
PASSIVE SAFETY ACTIVE SAFETY
RISK REDUCTION MEASURES/ INCIDENT
MANAGEMENT Rf
LO
SS O
F W
AT
ER
TIG
HT
IN
TE
GR
ITY
HA
ZID
(T
anke
r D
atab
ase)
Calibration of Pf through pertinent
scenarios, using structural reliability, to match historical risk
STAY AFLOAT Pfi
POP&C – Focus of ApplicationTo demonstrate the developed methodology, POP&C consortium agreed to consider AFRAMAX class of tankers.
However the methodology is applicable to any type or size of tanker.
Therefore, the foregoing discussion will be specific to AFRAMAX class of tankers.Aframax Tanker Fleet double-hull Development
6449 46 42
36 31 28 23
6
66
54
4 33
25
2119
18
1513
12
9
5
2429
3545
52 5765
0%
20%
40%
60%
80%
100%
1990 1992 1994 1996 1998 2000 2002 2004
% d
wt
shar
e
DH share (%)
DS share (%)
DB share (%)
SH share (%)
Hazard Identification and Ranking
Objective:To identify hazards such as grounding and collision, fire and explosion, structural failure with potential to lead to vessel’s loss of watertight integrity and consequently to pollution and environmental damage.
– Compilation and analysis of tanker accidents database
– Identification and selection of method(s) suitable for the hazards identification and ranking (techniques such as tabular HAZID, FT/ET analysis, and networks will be considered).
– Identification and ranking of relevant hazards
– Selection of critical scenarios
Outcomes of HAZID Analysis– An AFRAMAX tanker incidents database was compiled and a
comprehensive analysis was performed.
– Historical Data Analysis yielded that most important Hazards for Tankers are
– Collisions, Contact, Grounding,– Fire, Explosions, and Non-accidental Structural failure
– A method utilising both Fault Trees and Event Trees was chosen. Fault Trees and Event Trees were developed for these Hazards
– FTs and ETs were populated based on historical data analysis and expert judgment
Example-Grounding Fault Tree
Example-Grounding Event Tree
Loss of Damage Stability
Objective: To assess the survivability performance of a tanker following breach of watertight integrity of the hull from damage stability and sinkage points of view.
Specific Work Performed/Required
– Existing probabilistic survivability assessment models were evaluated for tanker ships
– Damage extents for Non-accidental structural failure, Fire, and Explosions were developed.
– Population of AFRAMAX tanker fleet configurations were identified
– A survivability index (Attained Index of Subdivision - A) is determined for the critical scenarios identified in Hazard Identification and Ranking study
– Index A is calibrated against the derived historical risk
Example Damage Scenario
Figure : Damage to transverse bulkhead between tanks 2 and 3
Sample Calculations
Vessel Name Lt Ship LS LCG MS LS KG Type Arrgt N. Tanks Capacity [m^3]Aframax SH 4x3 8+2 13538 11.300A 11.60 SH 4x3 8+2 115930Aframax SH 4x3 7+2 16680 13.280A 11.60 SH 4x3 7+2 98528Aframax SH 5x3 12+1 15244 9.933A 10.95 SH 5x3 12+1 78173Aframax SH 5x3 11+2 14831 12.510A 11.98 SH 5x3 11+2 102309Aframax DB 5x3 19 18831 13.206A 14.12 DB 5x3 19 100717Aframax DH 6x2 12+2 small 16638 10.100A 11.24 DH 6x2 12+2 121147Aframax DH 6x2 12+2 large 19004 10.803A 11.19 DH 6x2 12+2 131301Aframax DB 6x3 18 16361 10.863A 11.38 DB 6x3 18 110989Aframax DS 7x1 7+4 13699 13.090A 12.61 DS 7x1 7+4 82724Aframax DH 7x1 7+2 13964 12.378A 13.59 DH 7x1 7+2 110650Aframax DH 7x2 14+2 19346 11.29A 11.10 DH 7x2 14+2 93954Aframax SH 7x3 21 21735 15.950A 11.05 SH 7x3 21 121800Aframax DS 8x1 8+3 17319 16.210A 13.29 DS 8x1 8+3 112061
Outflow/Capacity
0.000
1.000
2.000
3.000
4.000
5.000
6.000Bottom
Side Historical Bottom
Historical SideHistorical Bottom 2
Aframax Tanker Configuration Data
Probability of Survival after damage Oil outflow capacity
Structural Reliability
Objective:
To determine the probability that the hull structural integrity will be lost in the event of the watertight integrity of the hull being breached.
Specific Work Areas of Structural Integrity
– Development of specific scenarios for loss of structural integrity
– Collision Analysis of single hull and double hull tankers
– Residual strength analysis using non-linear FE,
– Development of simplified model to account for damage ship structural strength
– Assessment of residual structural strength for critical damage scenarios
Collision Analysis
web_ballast Plt_ballast
web_fullload plt_fullload
max (Seqv) = 591MPa max (Seqv) = 596MPa
max (Seqv) = 562MPa max (Seqv) = 657MPa
Fig. 2.1-1 von Mises stress at sub-step 5
Collision Damage Locations/ Collision Angles
Angle = 60 degrees Angle = 45 degrees
Angle = 90 degrees Angle = 75 degrees
Fig. 2.2-1 Relative positions of colliding ships
Single Venture - Double Venture Comparison
max (Seqv) = 504MPa max (Seqv) = 540MPa
Single Venture Double Venture
Figure 1 : Comparison between Single Venture and Double Venture contours of von Mises stress at sub-step 10
Single Venture - Double Venture Comparison
Single Venture Double Venture
Figure 1 : Comparison between Single Venture and Double Venture displacements of bow vs. time (s) (friction included and 90o contact angle)
Single Venture - Double Venture Comparison
Single Venture Double Venture
Figure 1 : Comparison between Single Venture and Double Venture contact force vs. displacement (N-m) (friction included and 90o contact angle)
Damage Extent- Marpol (mostly single hull tankers)
SIDE: Longitudinal Extent
11.95
3.5
0.35 0.350
2
4
6
8
10
12
14
0 0.05 0.1 0.15 0.2 0.25 0.3
Damage Length/Ship Length
Pro
b. D
ensi
tySIDE: Transverse Penetration
24.96
5.00
0.56 0.56
0
5
10
15
20
25
0 0.05 0.1 0.15 0.2 0.25 0.3Transverse Penetration/Ship Beam
Pro
b. D
ensi
ty
SIDE: Vertical Extent
0.50
0.50
3.83
0
1
2
3
4
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Damage Extent/Ship Depth
Pro
b. D
ensi
ty
Damage Extent- Derived for double hull tankers
SIDE: Transverse Penetration
26.652
0.5360.536
4.264
0
5
10
15
20
25
30
0 0.05 0.1 0.15 0.2 0.25 0.3
Transverse Penetration/Ship Beam
Pro
b. D
ensi
ty
SIDE: Longitudinal Extent
3.2
0.27 0.27
12.79
0
2
4
6
8
10
12
14
0 0.05 0.1 0.15 0.2 0.25 0.3
Damage Length / Ship Length
Pro
b. D
ensi
ty
SIDE: Vertical Extent
0.483 0.483
3.93
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Damage Extent/Ship Depth
Pro
b.
Density
Overall Passive Pollution Risk
Objective:
To determine an overall risk index through– Determining consequences of oil outflow, loss of
vessel and loss of lives /injuries (and other pertinent costs) in the form of an Index
– Developing risk acceptance criteria for each risk element or the combined risk
– Developing a Risk-Based Design and Assessment Methodology
RISK
livespropertypollution
lives
property
pollution
kagestrengthcapsize
failurestructural
losion
fire
grounding
contact
collision
failurestructural
losion
fire
grounding
contact
collision
WWWx
C
C
C
xPPPx
P
P
P
P
P
P
R
R
R
R
R
R
,,,, sin
expexp
Risk = Frequency of Occurrence x Consequence
Frequencies of main Hazards
Consequence Analysis
Damage survivability
Structural Integrity
i=collision, contact, grounding, fire, explosions, structural failure.
6
1iitotal RR
Pollution Prevention
Objective:
To identify a risk reduction index (or reduction in frequency of events leading to major hazards) if active measures are taken to prevent oil spills through
- Identification of measures to reduce pollution risk by prevention - Examination of scenarios and developing counter measures
- Identification of generalised scenarios and counter measures.
Pollution Mitigation and Control
Objective: To formulate a pollution mitigating and control framework capable to cover adequately oil spill incidents/accidents generated from maritime transport players, namely vessels (tankers) through
– identification, ranking and assessing a critical mass of RCOs and PCOs
– pinpoint on-board (and nearshore) procedures, processes, policies, guidelines, technologies, innovations and practices, along with human factor aspects
– post-accident pollution control activities, such as on-board confinement, safe refuge operations
– Risk reduction by reducing consequences
RISK Reduction
livespropertypollution
lives
property
pollution
kagestrengthcapsize
failurestructural
losion
fire
grounding
contact
collision
failurestructural
losion
fire
grounding
contact
collision
WWWx
C
C
C
xPPPx
P
P
P
P
P
P
R
R
R
R
R
R
,,,, sin
expexp
ΔR = Δ(Pi) x ΔCj
Reduction in frequencies of main Hazards (Prevention)
Reduction in consequences
Reduction in frequencies of capsize or loss of structural integrity
Recent Dissemination ActivitiesCountries Size of Partneraddressed audience responsible
/involved
Conference, ENSUS Industry (Marine), NTUA-SDL/
2005 Conference, Higher Education, INTERTANKO,
Newcastle, UK Research BV, NAME-SSRCConference, 2 Papers
in IMAM 2005Industry (Marine), BV / NTUA-
SDL,Conference, Lisbon, Higher Education, NAME-SSRC,
Portugal. Research INTERTANKO
Sep-05 Lloyd’s List Industry (Marine) International INTERTANKO/BV, NTUA-SDL
Industry (Marine),
Higher Education,
Research
Industry (Marine), NTUA-SDL/
Higher Education, INTERTANKO,
Research NAME-SSRC, BV
Feb-06 Article in INTERTANKO Weekly News
Industry (Marine) International 1,600 INTERTANKO/ NTUA-SDL, NAME-SSRC, BV
4,000 BV
Jan-06 Conference, 1 paper in RINA 2006, London, UK
International
Nov-05 VERISTAR NEWS Industry (Marine) International
Dec-05 IMO News International INTERTANKO/BV, NTUA-SDL
International 100-150
Sep-05 International 150-200
Actual date Type Type of audience
Apr-05
Concluding Remarks
• The POP&C project aims to improve the overall safety in transportation of hazardous goods through the development of a risk-based methodology that encompasses ship design and operation (passive and active safety).
• In this respect, the focus is twofold:- Existing tankers: to contain risk through identifying/evaluating cost-effective measures of pollution prevention/mitigation by active means.- New designs: to approach design of new tankers rationally by integrating systematically risk analysis in the design process, addressing prevention/ reduction of pollution risk by passive and active means by a direct (first-principles) approach.
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