Vessel

Abstract

A vessel comprising a plurality of hulls, a propulsion system including propulsion devices at respective end regions of the plurality of hulls and a control system connected to the propulsion system to control operation of the propulsion devices so as to position the hulls, wherein the propulsion devices are angled relative to the vertical longitudinally of each hull. Such vessel can perform installation functions of sub-surface assets such as tidal turbines, wave energy devices, cable laying and the like, or to facilitate foundation installations and also the function of inspecting sub-surface areas.

I claim: 
     
         1 . A vessel comprising a plurality of hulls, a propulsion system including propulsion devices at respective end regions of said plurality of hulls and a control system connected to said propulsion system to control operation of said propulsion devices so as to position the hulls, wherein said propulsion devices are angled relative to the vertical longitudinally of each hull. 
     
     
         2 . A vessel according to  claim 1 , wherein said plurality of hulls is two. 
     
     
         3 . A vessel according to  claim 1 , wherein said propulsion system includes four propulsion devices located at both end regions of each hull. 
     
     
         4 . A vessel according to  claim 1 , wherein the propulsion devices are located in corner regions of the vessel taken as a whole. 
     
     
         5 . A vessel according to  claim 1 , and further comprising skegs and/or rudders provided on each hull. 
     
     
         6 . A vessel according to  claim 5 , wherein said skegs and/or rudders are retractable. 
     
     
         7 . (canceled) 
     
     
         8 . A vessel according to  claim 1 , wherein said control system is a computer controlled system which automatically maintains the vessel's position and heading by using the propulsion devices and wherein position reference sensors, wind sensors and motion sensors together with gyro compasses provide information to the computer pertaining to the vessel's position and the magnitude and direction of environmental forces affecting its position. 
     
     
         9 - 12 . (canceled) 
     
     
         13 . A vessel according to  claim 1 , the arrangement being such that each hull is symmetrical about a substantially vertical plane transverse to a longitudinal axis of each hull. 
     
     
         14 . A vessel according to  claim 1 , and further comprising an inspecting arrangement mounted to at least two of the plurality of hulls to inspect an area outwardly away from said vessel. 
     
     
         15 . A method comprising positioning at a location a vessel having a plurality of hulls and utilising a control system to operate a propulsion system of said vessel in order to substantially maintain the position of the hulls at the location. 
     
     
         16 . (canceled) 
     
     
         17 . A method according to  claim 15 , wherein said control system is a computer controlled system which automatically maintains the vessel's position and heading by using propulsion devices of the propulsion system and wherein position reference sensors, wind sensors and motion sensors together with gyro compasses provide information to the computer pertaining to the vessel's position and the magnitude and direction of environmental forces affecting its position. 
     
     
         18 . A method according to  claim 15 , and further comprising inspecting an area outwardly away from said vessel. 
     
     
         19 . A method according to  claim 15 , wherein said vessel is according to  claim 1 . 
     
     
         20 . A vessel comprising a plurality of hulls substantially parallel to each other, the arrangement being such that each hull is symmetrical about a substantially vertical plane transverse to a longitudinal axis of each hull. 
     
     
         21 . A vessel according to  claim 20 , wherein each hull is symmetrical from front-to-back about a substantially vertical central transverse plane across each hull. 
     
     
         22 . A vessel according to  claim 20 , wherein the shape of a bow and a stern of said vessel are substantially identical. 
     
     
         23 . A vessel according to  claim 20 , and further comprising a moon pool in a deck structure supported by the hulls. 
     
     
         24 . A vessel according to  claim 20 , wherein the hulls have an elliptical form geometry. 
     
     
         25 - 33 . (canceled)