Mounting of Inner Support Structure on the Swedish Warship Vasa : Product Development

Abstract: The master’s thesis is focused around the mounting of an inner support structure to the Swedish warship Vasa and was given by Camatec Industriteknik AB. The Swedish warship Vasa is one of the greatest national treasures of Sweden. The ship was built high and narrow, therefore a small gust of wind made her capsize during her maiden journey. Today it is the world’s bestpreserved ship from the 17th century and has been on display for the public at the Vasa museum since the year 1990. The purpose of the master’s thesis was to generate and evaluate concepts for the mounting of the inner support structure to the Swedish warship Vasa. The master’s thesis had the following goals: To generate and analyse possible concepts regarding the mounting. Final proposals of the mounting created in CAD. FEM calculations of the final proposals to ensure that they handle the load conditions properly. The master’s thesis followed the methodical process of product development with the steps: pilot study, concept generation, concept selection and concept evaluation. Three concepts were selected for further analysis. Two concepts involved a timber tong around the hanging knees. One fastened in a present structure of the ship (concept Y2.1) and the other one attached clamping force created by a spring in the construction (concept Y2.2). The third concept was a metal sheet between the main wales at the outside of the ship (concept G5). The concept Y2.1 was eliminated due to high local stress concentrations at the attachment in the ship. The concept Y2.2 showed some desirable features, including visual representation if tension was present. However, it was not ensured that the concept can keep the surface pressure below the maximum 0.15 MPa. Another uncertainty with the concept was the behaviour of the timber tongs if movement of the hull occurred. Therefore, the concept Y2.2 needs additional work before it can be continued or eliminated. The concept G5 handled the loading case without exceeding the required surface pressure. However, a decision whether the metal sheets would be to visible for visitors needs to be taken before continuing with or eliminate the concept. In summary, the concepts need further analysing before a final concept selection can be done.