Risk analysis of collision-damaged ship structures
Examensarbete för masterexamen
Naval architecture and ocean engineering (MPNAV), MSc
Bangera, Pavan Janardhana
Ullal, Anirudh Mallya
Shipping is the biggest mode of transport for bulk goods both by volume and value. But there were many cases where the shipping owners had to face huge losses due to ship-ship collisions, indirectly affecting the revenue flow in the shipping market. To quantify the consequences and reduce the loss behind these setbacks, an engineering solution of risk analysis has been done for a collision-damaged vessel. Three major post-collision hazards are considered in the scope of this thesis. Risk analysis on these three major hazards is done to quantify the severity of the consequences faced after a collision. The whole objective of this thesis is to build a general methodology that accounts for the stability risks of any vessel after damage, assesses the structural safety and ultimate strength risk, and develops an oil pollution response model that presents an economic valuation of the environmental impacts caused by the collision. Three methodologies are built addressing two different locations to showcase the accident based on the marine traffic density and history of ship collision on the west coast of Sweden. The analysis is made reliable by directly mapping the wave characteristics of the accident location on the seakeeping, survival probability, ultimate strength exceedance probability, and oil drift assessments. Considering the vulnerability, two ship types (RoPax & tanker) were used to showcase the versatility of the developed methodologies. A graphical user interface of the risk analysis tool is developed for all three major risk modules. The influence of the wave characteristics of the location on the risks are shown. The damage stability risk tool presents the motion responses and the survival risks; the ultimate strength risk tool delivers the ultimate strength exceedance probability, consequence, risks, and proposes mitigation actions; finally, the oil pollution response tool quantifies the consequences concerning the environmental impacts in the Swedish waters. It was shown that the wave characteristics vary for different locations in the same region and have a significant influence on the results of the risks on both RoPax and tanker vessels. It was concluded that the damage stability risk is sensitive towards the maximum time for evacuation. It was also shown that the simple act of manoeuvring the vessel can be an efficient way of ultimate strength risk mitigation. Analysing the oil drift simulation results it was concluded that viscosity and density play a very major role during the oil pollution response cost assessment.
Consequence analysis , metocean statistics , oil discharge , oil pollution response , probability of capsizing , risk analysis tool , rose plots , survival probability , ULS risk