Risk assessment of LNG and FLNG vessels during manoeuvring in open sea

Manoeuvring of a Liquefied Natural Gas (LNG) carrier in open sea at Floating LNG (FLNG) terminals can be associated with several operational risks of potential consequences to human safety, the environment and economy. In this paper, a fuzzy set approach was developed to handle the uncertainty in expert opinions commonly used for qualitative risk assessment studies such as the risk matrix. Risk parameters were modelled using a number of fuzzy sets, and a fuzzy risk value was calculated for several hazardous scenarios at different phases during ship berthing operations. The calculated fuzzy risk values were found to be consistent with the results of the risk matrix technique.