Steering and propulsion arrangement for ship

Abstract

The present invention relates to a steering and propulsion arrangement in a large ship suited for transoceanic traffic, which arrangement comprises a number of propulsion devices situated partly at the rear and partly at the forebody of the ship. The forebody of the ship is provided with one or more steerable rudder propeller devices, which are arranged so as to substantially provide the steering and control of the ship, to produce a substantial part of the propulsive force pushing the ship forward at least substantially within all speed ranges, and in addition, arranged so that they do not extend, at least not significantly, below the base line of the ship.

1 - 5 . (canceled)  
   
   
       6 . A large ship having a hull with a narrow wedge-like bow and the broadest part of the underwater hull being located amidships, and the length of the ship being about 100 meters or more, so that the ship is suited for transoceanic traffic, said ship being provided with a steering and propulsion arrangement comprising a number of propulsion devices situated partly at the rear and partly at the forebody of the ship, wherein the forebody of the ship is provided with one or more steerable rudder propeller devices, which are arranged and dimensioned so as to substantially provide the steering and control of the ship and to produce a part of the propulsive force pushing the ship forward at least substantially within all speed ranges such that in so-called harbour manoeuvering they can cover, as needed, at least about 20% of the ship's total propulsive power and when steering ahead in sea traffic they cover preferably at most about 10% of the ship's total propulsive power, said steerable rudder propeller devices being additionally arranged so that they do not extend, at least not significantly, below the base line of the ship.  
   
   
       7 . A steering and propulsion arrangement according to  claim 6 , wherein at the forebody of the ship in the underwater section of the hull at a distance from the base line of the ship, there is an area, which is designed sufficiently flat so that it enables the mounting and free turning of said one or more rudder propeller devices, and that the bottom of the ship hull from said area towards the stern is smoothly shaped so that the rudder propeller devices, while the ship is moving ahead, can be directed according to the shape of the ship hull, whereby the flow behind the rudder propeller device towards the hull surface can be minimized accordingly.  
   
   
       8 . A steering and propulsion arrangement according to  claim 7 , wherein in case the ship is provided with a bulb, said area is situated behind the bulb.  
   
   
       9 . A steering and propulsion arrangement according to  claim 6 , wherein there are at least two rudder propeller devices at the forebody of the ship.  
   
   
       10 . A steering and propulsion arrangement according to  claim 6 , wherein all the propulsion devices of the ship are permanently situated outside the ship hull.