The Influence of Collision Damage at the Bilge on a Double Hull Tanker to the Ultimate Strength

Damage to a ship’s structure can occur at any time and in any location, including incidents like grounding or collision that might affect various parts of the ship. This necessitates that structural design criteria account for such damage. The objective of this research is to investigate the impact of damage caused by collisions in the bilge area on the overall strength on a double hull tanker (DHT). To analyze the effects of collision damage, the study employs Smith’s method for the analytical solution. The DHT is examined in two scenarios: when it is intact and when it has sustained damage. During both hogging and sagging conditions, the DHT’s cross section is maintained as a plane throughout the progressive collapse. Material properties, including the dimensions of plates and stiffened plates, are kept constant. The DHT’s dimensions are 44 m in breadth and 21.2 m in depth, with the longitudinal length equal to one frame space. The results suggest that a double hull tanker experiences reduced ultimate strength when subjected to collision-induced damage in the bilge, compared to its strength in an undamaged condition. This study presents the results using moment versus rotation analysis and also describes the progressive collapse observed.