Buoyancy element and module

Abstract

A buoyancy element (200) is disclosed which comprises a moulded body of plastics-composite material incorporating reinforcement (202) comprising at least one elongate flexible member or filament, embedded in the body and adapted to retain fragments of the buoyancy module together following structural failure of the module.

1 . A buoyancy module for mounting on an underwater conduit in a string comprising two or more such modules arranged end-to-end, the buoyancy module being provided with means for transmitting force to its neighbouring module in the string in a direction along the length of the conduit while facilitating angular deflection of the module relative to its neighbour.  
   
   
       2 . A buoyancy module as claimed in  claim 1  wherein the means for transmitting force is formed by an end face at the buoyancy module, which is tapered or curved to facilitate angular deflection of the module relative to its neighbour.  
   
   
       3 . A buoyancy module as claimed in  claim 1  wherein the means for transmitting force comprises a resilient spacer for placement between end faces of the module and its neighbour.  
   
   
       4 . A buoyancy module as claimed in  claim 3 , in which the resilient spacer is formed of polyurethane.  
   
   
       5 . A buoyancy module as claimed in  claim 3 , in which the resilient spacer covers substantially the entire end face of the buoyancy module.  
   
   
       6 . A buoyancy module as claimed in  claim 3 , in which the resilient spacer is a moulding formed in situ upon end face of the buoyancy module.  
   
   
       7 . A buoyancy module as claimed in  claim 3 , in which thickness of the resilient spacer is between 1 inch and 6 inches.  
   
   
       8 . A riser tower comprising multiple buoyancy modules as claimed in  claim 3 .  
   
   
       9 . A buoyancy module for mounting on an underwater conduit in a string comprises two or more modules arranged end-to-end, the buoyancy module being provided with a resilient spacer for transmitting force to its neighbouring module in the string in a direction along the length of the conduit while facilitating angular deflection of the module relative to its neighbour.  
   
   
       10 . A buoyancy module as claimed in  claim 9 , in which the resilient spacer is formed of polyurethane.  
   
   
       11 . A buoyancy module as claimed in  claim 9 , in which the resilient spacer covers substantially the entire end face of the module.  
   
   
       12 . A buoyancy module as claimed in  claim 9 , in which the resilient spacer is a moulding formed in situ upon an end face of the buoyancy module.  
   
   
       13 . A buoyancy module as claimed in  claim 12 , in which thickness of the resilient spacer is between 1 and 6 inches.  
   
   
       14 . A buoyancy module for mounting on an underwater conduit in a string comprises two or more such modules arranged end-to-end, the buoyancy module having an end face for transmitting force to its neighbouring module in the string in a direction along the length of the conduit, the said end face being tapered or curved to facilitate angular deflection of the module relative to its neighbour.  
   
   
       15 . A riser tower comprising multiple buoyancy modules as claimed in  claim 9.