As the recession in shipbuilding industry became longer, domestic shipbuilders focused on the need for high value added and high technology, and strived to build safer vessels. There are LNG carriers and container ships that require representative technologies. Both ship types are rapidly increasing ship size in the 2000s. Recently, there have been the increase of ship size and the development of oil and gas in arctic region. These trends have led to the requirements such as high strength, good toughness at low temperature and good weldability for prevent of brittle fracture at service temperature. Studies on unstable fracture have mainly been conducted to evaluate the brittle crack stopping properties of the high strength steel welded joints through large scale fracture tests, and studies on the difficulty of stopping brittle cracks in welded joints. It is known that BCA (Brittle Crack Arrest) steel has recently been developed to prevent unstable fracture if cracks propagate toward the BCA steel even if brittle cracks occur. Therefore, it is considered that the ship can be dried more easily if a technology capable of inducing the brittle crack to the BCA steel is developed. In this study, we describe a technique for securing unsafe fracture safety by inducing cracks toward the BCA steel, which has excellent brittle crack stopping ability, regardless of the welding process when brittle cracks occur in the superstructure of super large container ships. Key words: Brittl crak arrestability, Crack arrest toughness, Thick steel plate, FCAW, ESSO test, Welding residual stress