Tugboat Having Azimuthal Propelling Units

Abstract

A tugboat having azimuthal propelling units, comprising at least two juxtaposed azimuthal propelling units, characterized in that each of the juxtaposed propelling units has a main shaft with a main axis extending at an angle relative to at least one of a main plane of symmetry or a transverse center plane of the tugboat.

1 . A tugboat comprising at least three azimuthal propelling units of which at least two are juxtaposed propelling units, wherein each of the juxtaposed propelling units has a main shaft with a main axis extending at an angle relative to at least one of a main plane of symmetry to a transverse center plane of the tugboat. 
     
     
         2 . The A tugboat according to  claim 1 , wherein the main shafts of the at least two juxtaposed propelling units have a main axis which has an inclination defined by said angle or angles mirrored relative to the main plane of symmetry of the tugboat. 
     
     
         3 . The tugboat according to  claim 1 , wherein the main shafts of the at least two juxtaposed propelling units have a main axis which is inclined and substantially lies in a plane parallel to the transverse center plane. 
     
     
         4 . The tugboat according to  claim 1 , wherein the main shafts of the at least two juxtaposed propelling units have a main axis which is inclined relative to the transverse center plane and to the main plane of symmetry. 
     
     
         5 . The tugboat according to  claim 1 , wherein the tugboat has a third azimuthal propelling unit at a length position different from the length positions of said at least two juxtaposed azimuthal propelling units. 
     
     
         6 . The tugboat according to  claim 5 , wherein the third azimuthal propelling unit is disposed at a length position which is located before or is equal to the length position of a towing point or a rearmost towing point respectively of the tugboat. 
     
     
         7 . The tugboat according to  claim 5 , wherein the third azimuthal propelling unit has a main shaft with a main axis extending at an angle relative to the main plane of symmetry, wherein the angle is between 1 and 15 degrees. 
     
     
         8 . The tugboat according to  claim 1 , wherein the at least two juxtaposed propelling units each have a main shaft with a main axis extending at at least one of:
 an angle relative to the main plane of symmetry of the tugboat, wherein the angle is between 1 and 15 degrees; or   an angle relative to the transverse center plane of the tugboat.   
     
     
         9 . The tugboat according to  claim 1 , wherein at least one propelling unit is mounted to a hull of the tugboat by a well or pot which extends inside the hull. 
     
     
         10 . The tugboat according to  claim 9 , wherein said well or pot comprises a peripheral wall extending around part of the main shaft of a propelling unit, wherein a lower side of the peripheral wall is mounted on or to a sloping surface part of the hull. 
     
     
         11 . The tugboat according to  claim 1 , wherein a hull of the tugboat is provided with an indentation or recess such that a propeller or propeller nozzle is in close proximity off or extends partly inside said indentation or recess. 
     
     
         12 . The tugboat according to  claim 1 , wherein each propelling unit has a main direction of thrust, preferably directed perpendicular to the main axis of the each propelling unit, wherein the at least two juxtaposed propelling units are mounted such that when their main direction of thrust in a top view are directed in the same direction and substantially intersecting, the main direction of thrust of a first of the at least two juxtaposed propelling units is directed below the main direction of thrust of a second of the at least two juxtaposed propelling units. 
     
     
         13 . The tugboat according to  claim 1 , wherein at least for the at least two juxtaposed propelling units the respective main axis crosses a hull of the tugboat, seen in a front or rear a view, at a substantially right angle. 
     
     
         14 . The tugboat according to  claim 1 , wherein with each propelling unit a separate driving engine is associated, wherein the tugboat further comprises a fire extinguishing installation having one fire extinguishing pump that can be coupled to one of said three driving engines. 
     
     
         15 . The tugboat according to  claim 1 , wherein with each propelling unit a separate driving engine is associated, wherein the tugboat further comprises a fire extinguishing installation having two fire extinguishing pumps coupled to two of said driving engines. 
     
     
         16 . The tugboat according to  claim 10  wherein the peripheral wall is at least one of substantially cylindrical or frusto conical and has a central axis substantially parallel to the main axis of the relevant propelling unit. 
     
     
         17 . The tugboat according to  claim 16  wherein the central axis is substantially coaxial with the main axis of the relevant propelling unit. 
     
     
         18 . The tugboat according to  claim 15  wherein the two fire extinguishing pumps are coupled to the driving engines associated with said two juxtaposed propelling units and wherein one driving engine at most is provided with a slip coupling between said driving engine and the associated propelling unit.