Reliability and residual strength of double hull tankers designed according to the new IACS common structural rules

This paper studies the residual strength of three double hull tankers designed according to the new International Association of Classification Societies (IACS) common structural rules (CSR). Different damage scenarios at side and bottom are considered with different damage size to define a lower limit of strength which might be accounted for during design. The residual strength is calculated using progressive collapse method (PCM) and applying the failure modes defined in the new rules. The reduction in section modulus (SM) due to damage is considered to check whether the section modulus is still acceptable after damage. A design modification factor (DMF) is applied to the deck thickness to compensate for the strength lost with damage. The reliability of the three ships is calculated considering the worst scenarios. The change in the still-water bending due to damage is taken into account while calculating the reliability. The effect of damage on the reliability is also studied.