Ship Hull and a Method of Manufacturing Such a Hull

Abstract

A ship hull, especially intended for oil and chemical ships, passenger ships are fishing ships, comprising a hull made of steel or aluminium built on a supporting structure of frames, stringers and longitudinals, having improved buoyancy and energy absorbing capability, and a method of manufacturing such a ship. Between an outer hull ( 200 ) and an inner hull ( 202 ) a layer ( 204 ) of a cellular plastic material is applied having chiefly closed cells. The outer hull is made of a high strength steel, wherein at external strain the outer hull and the cellular plastic material are adapted to jointly constitute an energy absorbing deformation zone.

1 - 22 . (canceled)  
   
   
       22 . A ship hull comprising: 
 an inner hull built on a supporting structure of frames, stringers and longitudinals;    an outer hull; and    a cellular plastic material applied between the inner hull and the outer hull, said cellular plastic material having closed cells for improved buoyancy and energy absorbing capability wherein 
 the inner hull is made of at least one of aluminium and steel;  
 the outer hull is made of a high strength steel; and  
 at external strain, the outer hull and the cellular plastic material are adapted to jointly constitute an energy absorbing deformation zone.  
   
   
   
       23 . A ship hull according to  claim 22 , wherein the outer hull and the cellular plastic material are adapted such that in the case of external strain, said deformation zone absorbs enough stress to make the inner hull collapse or break before the outer hull.  
   
   
       24 . A ship hull according to  claim 22 , wherein the thickness of the cellular plastic material is adapted to the total weight of the ship in order to obtain buoyancy.  
   
   
       25 . A ship hull according to  claim 22 , wherein the thickness of the cellular plastic material is between 0.05 m to 3.0 m and the thickness of the high strength steel is between 0.005 m to 0.030 m.  
   
   
       26 . A ship hull according to  claim 22 , wherein the cellular plastic material is one of expanded polypropylene, expanded polythene, expanded PVC, expanded polystyrene, expanded PET, cross linked and non-cross linked materials.  
   
   
       27 . A ship hull according to  claim 22 , wherein the cellular plastic material is glued on an outside of the inner hull.  
   
   
       28 . A ship hull according to  claim 27 , wherein the outer hull is glued on the cellular plastic material.  
   
   
       29 . A ship hull according to  claim 28 , wherein a glue used for gluing the cellular plastic material is a glue that forms a dilatation joint during hardening.  
   
   
       30 . A ship hull according to  claim 22 , wherein at least one highly elastic layer is further arranged between the inner hull and the outer hull and functions as a membrane.  
   
   
       31 . A ship hull according to  claim 30 , wherein a material in the highly elastic layer is one of rubber, an elastomer or a polymer.  
   
   
       32 . A ship hull according to  claim 30 , wherein the highly elastic layer is formed by a glue used for gluing together the hull and the cellular plastic material.  
   
   
       33 . A method of manufacturing a ship hull comprising an inner hull and an outer hull, said method comprising: 
 attaching a layer of cellular plastic material having closed cells to the inner hull and the outer hull, wherein 
 the inner hull is made of at least one of steel and aluminium and built on a supporting structure of frames, stringers and longitudinals;  
 the outer layer is made of high strength steel; and  
 at external strain, the outer hull and the cellular plastic material are adapted to jointly constitute an energy absorbing deformation zone.  
   
   
   
       34 . A method according to  claim 33 , further comprising: 
 adapting the outer hull and the cellular plastic material such that in the case of external strain, said deformation zone absorbs enough stress to make the inner hull collapse or break before the outer hull.    
   
   
       35 . A method according to  claim 33 , further comprising: 
 gluing blocks of cellular plastic material having mainly closed cells to the inner hull;    gluing a plurality of steel plates, each to one of said blocks of the cellular plastic material; and    welding the steel plates together to form an outer hull.    
   
   
       36 . A method according to  claim 35 , further comprising: 
 gluing blocks of a cellular plastic material having a glued layer of high strength steel to the inner hull.    
   
   
       37 . A method according to  claim 33 , further comprising: 
 providing a construction between the inner hull and the outer hull to separate the hulls at a predetermined mutual distance in order to form a gap; and    injecting a cellular plastic forming material with an adhesive in the gap.    
   
   
       38 . A method according to  claim 33 , wherein the cellular plastic material layer is designed with a thickness of 0.05 m to 3.0 m and the high strength steel is designed with a thickness of 0.005 m to 0.030 m.  
   
   
       39 . A method according to  claim 33 , wherein the cellular plastic layer is selected as having a density of 100-150 kg/m 3  including the adhesive.  
   
   
       40 . A method according to  claim 37 , wherein hull surfaces adjacent the gap are pre-glued with a glue giving rise to one of a dilatation joint and a visco-elastic glue joint, such as a dual component polyurethane glue, epoxy resin and moisture-hardening single component polyurethane glue or different types of prepegs.  
   
   
       41 . A method according to  claim 37 , wherein the adhesive is a thermosetting plastic or any other hardening adhesive.