There are many different types of tanks on ships that meet various requirements. Each tank is required to undergo hydrostatic testing according to the Ship Safety Act after being installed onboard. In some hydrostatic tests, excessive deformation may occur. The overpressure of the air in the tank generated during testing is one of the possible causes of deformation. Based on the dimensions of the tank, nozzle, and pipes installed, it was confirmed that the overpressure of the air can cause problems with the structure, according to the Bernoulli equation. Additionally, finite element analysis (FEA) was performed on the tank structure to confirm the deformation and the stress occurring in the structure. From the perspective of deformation, the maximum deflection limit was set based on the criteria provided by the Eurocode and DNV. From the perspective of stress, the structural safety assessment was performed by comparing the allowable stress and equivalent stress generated in the structure. To determine whether the behavior of the actual structure was well implemented via FEA, beam theory was applied to the tank structure and compared with the FEA results. As a result of the analysis, severe deformation was found in some cases. This means that the overpressure of the air may be the cause of actual deformation. It was also confirmed that permanent deformation may occur.

Structural design for shipbuilding is generally divided into three stages: the basic, detailed, and production designs, of which the production design is the most frequently revised among the three design stages. The revision involved in production design department was approximately 61% of the total 4,211 revision members and approximately 56% of the total 710 revision cases in the survey on the number of design revisions for nine ships. In this study, members and drawings with a high revision rate were investigated, and related design departments were identified. In addition, the work contents of the design department were analyzed to reduce the number of design revisions and three tasks are very frequently revised were selected. A survey was conducted with engineers engaged in the production design, after which, standards were proposed for the method of aggregating bills of materials, to employ macros to calculate the length of members and that of profile input data when reviewing drawings. Via the study, it was determined that the major causes of design revision are simple mistakes by engineers or lack of understanding on structural arrangement of basic members more than intricacies of prior design and high level specification. As a result of applying the proposed standards, it was confirmed that the design revision was reduced by approximately 40%.