Estimating Spills Caused by Chemical Tanker Collisions

in the Gulf of Finland Using Different Impact Models

MTE11 conference 12-14.10.2011

Świnoujście, Poland

by Otto Sormunen

Otto Sormunen (1), Floris Goerlandt (1), Kaarle Ståhlberg (1), JakubMontewka (1,2) & Pentti Kujala (1)

(1) Aalto University, School of Engineering, Department of Applied Mechanics,Espoo, Finland

(2)Maritime University of Szczecin, Institute of Marine Traffic Engineering

Overview of the presentation

Formal Safety Assessment

Overview of the presentation

• .

Accident Frequency

Analysis

PA|T : probability of accident

for hazardous material T

PB|A: probability of chemical

spill in case of accident PCS : probability of spill of

size X = RT

Accident Consequence

Analysis

- Traffic simulation to

obtain chemical tanker

collision frequency

- Comparing collision energy

to hull structural strength- Chemical spill size estimation

in case of a hull breach

Step 2:

Risk Analysis

No. of. hull

breaches &

spill sizes in GoF

PA|T : probability of accident for hazardous material T

• Simulation model by Goerlandt and Kujala (2011)

– Based on 2007 AIS data

PA|T : probability of accident for hazardous material T

• Division of GoF into 5 x 5 km squares

PA|T : probability of accident for hazardous material T

• Collisions from average of 24 simulation runs

PB|A : probability of chemical spill in case of accident

Evaluated based on collision energy vs hull structural strength

Collision energy modelby Zhang (1999)

PB|A : probability of chemical spill in case of accident

• Evaluated based on collision energy vs hull structural strength

Impact scenario models

Hull critical energy

(Zhang 1999), (Lützen 2001) and (HSE 2000)

(ABS 2010)

Different

proposals

Cargo area

PB|A : probability of chemical spill in case of accident

• Uncertainty

PA|T PB|A= E[hull breaches / year]

• Max = 0.0016, sum = 0.026 Max = 0.0024, sum = 0.038

•

•

• Max = 0.0011, sum = 0.018 Max = 0.00089, sum = 0.020

PA|T PB|A= E[hull breaches / year]

• Max = 0.0012, sum = 0.020 spills/year

RT = PA|T PB|A PCS

- Spill model by Montewka et al. 2010

• Max = 1.3, sum = 22.51 tons / year

FSA Step 3: Risk Control Options

• Oil- and chemical recovery vessels

Where should these be stationed?

Thank you for your attention

Questions?otto.sormunen@aalto.fi