Marine vessel propulsion arrangement and method of operating a marine vessel propulsion arrangement

Abstract

Marine vessel propulsion system comprising engine system ( 2 ) for producing propulsion power and several propulsion means ( 3, 9 ) at its stem section, including a combination of at least two propulsion arrangements ( 9 ) capable of steering action and at least one shaft driven propeller drive ( 3 ) having a controllable pitch propeller ( 6 ), being adjustable to substantially feathering conditions. The invention relates also to method of operating a marine vessel propulsion system in which at low speed and/or harbour manoeuvring operation the shaft driven propeller drive ( 3 ) is adjusted to be feathering and power transmission to the propeller ( 6 ) is stopped.

1 - 13 . (canceled)  
   
   
       14 . Marine vessel propulsion system comprising engine system for producing propulsion power and several propulsion means at its stern section, characterized by combination of at least two propulsion arrangements capable of steering action and at least one shaft driven propeller drive having a controllable pitch propeller, being adjustable to substantially feathering conditions.  
   
   
       15 . Marine vessel propulsion system according to  claim 14 , characterized in that the at least two propulsion arrangements capable of steering are azimuthing propulsion arrangements.  
   
   
       16 . Marine vessel propulsion system according to  claim 15 , characterized in that the azimuthing propulsion arrangements are provided with constant pitch propeller systems and/or variable pitch propeller systems.  
   
   
       17 . Marine vessel propulsion system according to  claim 15 , characterized in that the azimuthing propulsion arrangements are powered by electric motor, the power to which being supplied by piston engine generator set and that the shaft driven propeller drive is mechanically connected to a piston engine.  
   
   
       18 . Marine vessel propulsion system according to  claim 15 , characterized in that the propulsion system is arranged to be driven at different operation modes, when at normal/cruise speed operation mode both the at least two azimuthing propulsion arrangements and the at the least one shaft driven propeller drive are adapted to at least cause thrust in order to move the vessel, and at low speed/maneuvering operation mode only the at least two azimuthing propulsion arrangements are adapted to cause thrust in order to move the vessel.  
   
   
       19 . Marine vessel propulsion system according to  claim 14 , characterized in that pitch angle of blades in the propeller of the shaft driven propeller drive is adjustable to be either +80°-100° or −80°-100°.  
   
   
       20 . Marine vessel propulsion system according to  claim 14 , characterized in that the engine system comprises a coupling means connecting the propeller drive shaft to an engine and being shiftable to disengaged position.  
   
   
       21 . Method of operating a marine vessel propulsion system comprising at its stern section at least two propulsion arrangements capable of steering action and at least one shaft driven propeller drive having a controllable pitch propeller, wherein at normal/cruise speed 
 the propulsion thrust is provided by the shaft driven propeller drive and said propulsion arrangements capable of steering action and    steering thrust is provided by the propulsion arrangements capable of steering action, and    the thrust of the shaft driven propeller drive is mainly adjusted by adjusting pitch angle of the propeller,    characterized in that at low speed and/or harbor maneuvering operation the shaft driven propeller drive is adjusted to be feathering and that power transmission to the propeller is stopped.    
   
   
       22 . Method of operating a marine vessel propulsion system according to  claim 21 , characterized in that power transmission to the shaft driven propeller drive is stopped by disengaging the engine from the shaft of the shaft driven propeller drive.  
   
   
       23 . Method of operating a marine vessel propulsion system according to  claim 21 , characterized in that power transmission to the shaft driven propeller drive is stopped by stopping the engine.  
   
   
       24 . Method of operating a marine vessel propulsion system according to  claim 21 , characterized in that while the power supply to the propeller drive is stopped from the engine system, the at least two propulsion arrangements capable of steering action are maintained in operation.  
   
   
       25 . Method of operating a marine vessel propulsion system according to  claim 21 , characterized in that at low speed and/or maneuvering operation the pitch angle of propeller of the shaft driven propeller means is adjusted to be advantageously either +80-100° or −80-100°.  
   
   
       26 . Method of operating a marine vessel propulsion system according to  claim 21 , wherein the at least two propulsion arrangements capable of steering action are powered by electric motors, the power to which being supplied by one or more piston engine generator sets, characterized in that at low speed and/or harbor maneuvering operation piston engines of the piston engine generator sets are operated at greater speed than idle speed, substantially at their most efficient constant speed substantially independently from the power consumption of said propulsion arrangements.