Key configurations for design and fabrication of high speed offshore vessels

Abstract

With the development of the Norwegian and the Barents seas and by advancing the oil and gas industry further to the sea from the coastal line, the marine industry requires a class of different purpose vessels to operate them at a pretty large distance from the shore line. These vessels should also be capable of working in the conditions of the specific and harsh weather in the Norwegian and the Barents seas. This report describes the opportunities and abilities of multihull vessels by using examples of catamarans and trimarans. Examples of calculations of some methods and practical analysis of the opportunities will be the results here. In this report the opportunities and advantages of trimarans and catamarans will be compared. Where trimarans, by keeping all advantages of catamaran design (the larger deck area and cross-section stability), have a higher speed and are less addicted to the impact from longitudinal rolling and they are more stable on a water surface.. Multihulls are having a certain number of disadvantages, for example, water impacts (during roll) to the area, where the beam connects to the hull (it is more expressed for catamarans, because of the double hull structure and hulls connect to each other by a cross-section beam), the weight of the hull increases, because of the double or triple hulls, and there are difficulties during construction and repair. In this report "The elasto-dynamical theory of multihulls in nonlinear beam sea" will be considered. Also will the features of the water’s resistance to the motions of multihulls be studied. These are defined by the arrangement and geometry of the underwater part of the hull and will be shown. By the calculation of: - the resistance of catamarans with a cruiser stern - the resistance of a trimaran - the resistance of a high-speed catamaran. Furthermore, the most suitable propellers will be reviewed; and also some calculations of the interaction coefficient of the screw propeller and the catamaran's hulls and calculation of the propulsive quality of a catamaran in a still water will be carried out. This Thesis report describes the features and the opportunities of construction of the given types of the vessels at shipbuilding plants of Ukraine. Examples and data of the largest shipbuilding yards of Ukraine will be included. This report also focuses on specifications and considerations of oceanographic and geographic features of the Straits of Bosporus and Dardanelles for the opportunities of transportation from the Black Sea to the Mediterranean Sea through these Straits