Structural Integrity in Merchant Ships

Abstract

Since World War II, periodic changes in the fabrication, design, and material specifications for ship steels have been made to preclude brittle fractures. These various changes are described briefly, along with a history of fracture control for ships to serve as background information for a discussion of the present-day structural integrity program for ships in the marine industry. As additional information related to the structural integrity of ship structures, a review of two recent ship failures (e.g., the Ingram Barge in 1972 and the Chester A. Poling in 1977) is presented to demonstrate some of the factors involved in brittle fractures of ships. In both of these failures there were other factors contributing to the final brittle fractures that were more important than the notch toughness levels. These factors are reviewed as the basis for an observation regarding the overall structural integrity of merchant ships.