Manoeuvring Simulation and Control Studies for Application to Dry and Wet Towing of Jack Up Units

Ocean engineering

Williams, Owen Skae

University:University of Glasgow

关键词: Ocean engineering;   

Others  :  http://theses.gla.ac.uk/75509/1/13832111.pdf

来源: University of Glasgow

【 摘 要 】

The work contained in this Thesis presents manoeuvring simulation models which can be applied to the dry and wet towing of jack up units. The first chapter is a general introduction on the applications and methods of transportation of jack up units. In Chapter Two, a single vessel modular manoeuvring simulation model is presented and the modelling of wind and current loading is then discussed in Chapter Three. The wind loading on jack up legs is studied in Chapter Four using three models proposed by Det Norske Veritas, the British Standards Institution and Marathon Marine Engineering Company. The most appropriate leg loading model from this study is then incorporated into the simulation studies of the dry towing of a jack up on a heavy lift vessel in Chapter Five. The modelling of a skeg is also presented for these simulations. In Chapter Six, an experimental program is presented to obtain the linear drift manoeuvring derivatives and the current loading coefficients for a jack up geometry. In Chapter Seven, the Classical linear theoretical model and the extended analysis is presented for the prediction of directional stability of three single tow line systems. The system conditions for these theoretical studies are then simulated in two tow simulation models and the results are compared. The two tow simulation models employ a rigid and elastic tow rope assumption. These tow models are further compared under wind loading and for the location of the towed vessel superstructure. The elastic tow rope model is then extended to model the towing simulation with a bridle. The main conclusions to Chapter Two through to Seven are presented in Chapter Eight with some recommendations for towing operations and future work.