Light weight marine vessels operating in brash Ice

Abstract: This is a master thesis, done as a part of the ongoing research projects ”Vattenvägen 365” and ”LightIce - Light weight marine vessels operating in brash Ice”. This work is a study of the design of a high speed craft, intended for use in the public transportation network in the Stockholm area. Emphasis is put on investigating the consequences of the ice conditions in the area during winter. The work is primarily done as a case study, based on the design of a high speed passenger vessel, intended to navigate in ice. The ice conditions considered are light ice conditions, like brash ice and thin ice sheets. In connection with the high speed craft design, work is done on the effect of the choice of material concept. The scope of the work is as follows. To look into the existing literature on the topics of ice loads on high speed crafts and the use of lightweight materials in the construction of ice-going vessels. Create an initial design of a high speed craft suitable for passenger transportation in the Stockholm area. Gain insight into the ice loading on a high speed craft, and looking into the use of composite and lightweight materials.A literature review on literature related to ice loading of high speed crafts is done. A vessel is brought into the initial design stage, basing the design on a operational profile developed for a suggested route for commuter transportation in the Stockholm area. This high speed craft is used as a basis for comparison of different methods for estimation of ice loading. Testing is planned to investigate the ice loading of high speed crafts, based on the operational profile and vessel design. In connection with testing, a loading scenario is created by estimating the expected maximum ice thickness during a winter in the intended area of operation, an impact scenario is defined and work is done with regards to estimation of ice floe size and modelling of the impact between the vessel under normal operational conditions and an ice floe. For the testing, full scale hull panels are designed in four different materials, both metal and composite. Testing is planned using the defined loading and the designed hull panels.The thesis serves as a basis for conducting further research into the topic of ice loading of high speed crafts.