Prediction of the total resistance and the speed of the semi-submersible crane vessel sleipnir at different scenarios

Offshore oil and gas industry. they transport, install and remove all types of fixed and floating structures. for this purpose, hmc operates four crane vessels of which three are semi-submersibles (sscv). sscvs are characterized by two floaters with three or four columns on each floater supporting a single body upper hull structure. recently, the new vessel, sleipnir, has been built in order to overcome the next generation challenges of the sector, being able to lift 20.000tn with its two cranes. during transits and operations, cargo and equipment are fitted on deck of sscvs or on a barge, if it does not fit. however, nowadays it is becoming a possibility to transport a cargo (jacket, or topsides) while being suspended on the cranes. it is therefore of interest to know how will the crane vessels respond to this situation, as regards to motions and available speed. the objective of this thesis will be to give a prediction of the total resistance and the speed of the new vessel sleipnir at different scenarios. unlike other sscv, sleipnir has been designed so as it can sail by own propulsion so before this craft starts working on future projects, hmc desires to be able of predicting the different speeds that it will get for different scenarios of draught, waves and wind, when transporting a cargo while being suspended. the scope of doing this study is for the company to know how much time will be spending on sailing for different weather and cargo conditions of the vessel, and therefore to be able to predict the timing better. in order to do the calculations for this project, data from the preconstruction studies has been analyzed and cross checked with the speed trials. these studies, performed years ago, did not account on the possibility to perform such transit situations since it has a transit draught of 12m and this one only has been considered at detailed design stage. therefore, these studies did not give a speed prediction for it