Buoyancy Element

Abstract

The invention relates to a buoyancy module ( 100, 200, 300, 400, 500, 700 ) which comprises multiple buoyancy elements ( 104, 204, 304, 404, 504, 604, 704 ) coupled to one another. Each of the buoyancy elements has a recess ( 110, 210 ) and the buoyancy elements are laterally juxtaposed with their recesses aligned with one another to encircle the elongate member in use. Multiple buoyancy elements are stacked one upon another along a direction which is axial with respect to the elongate member in use, to form a buoyancy module of a predetermined axial depth. The recesses of the buoyancy modules together form an axially extending passage through which the elongate member passes.

1 . A buoyancy module for mounting on an elongate member to be deployed underwater, the buoyancy module comprising multiple buoyancy elements coupled to one another independently of the elongate member, wherein each buoyancy element has a recess and buoyancy elements are laterally juxtaposed with their recesses aligned with one another to encircle the elongate member in use, and wherein multiple buoyancy elements are stacked one upon another along a direction which is axial with respect to the elongate member in use, to form a buoyancy module of a predetermined axial depth, the recesses of the buoyancy modules together forming an axially extending passage through which the elongate member passes, in use. 
     
     
         2 . The buoyancy module as claimed in  claim 1  further comprising at least one locating feature which projects into the passage to engage in use with a clamp secured to the elongate member and thereby locate the buoyancy module against axial movement with respect to the elongate member. 
     
     
         3 . The buoyancy module as claimed in  claim 2 , wherein the at least one locating feature includes two locating features axially separated from one another to abut opposite sides of the clamp, in use. 
     
     
         4 . The buoyancy module as claimed in  claim 2 , wherein the passage is generally circular in section and the locating feature forms a through-going opening in the passage of internal diameter smaller than that of the passage. 
     
     
         5 . The buoyancy module as claimed in  claim 2 , wherein the locating feature is formed by a locating part sandwiched between axially neighbouring buoyancy elements. 
     
     
         6 . The buoyancy module as claimed in  claim 5 , wherein the locating feature is formed by at least one plate sandwiched between axially neighbouring buoyancy elements. 
     
     
         7 . The buoyancy module as claimed in  claim 6 , wherein the plate is captively received in a recess formed between the axially neighbouring buoyancy elements and surrounding the passage. 
     
     
         8 . The buoyancy module as claimed in  claim 3 , wherein the locating feature is formed by at least one of the buoyancy elements. 
     
     
         9 . The buoyancy module as claimed in  claim 1 , wherein the passage is circular and has a substantially constant diameter along its axial length. 
     
     
         10 . The buoyancy module as claimed in  claim 1 , wherein five or more buoyancy modules are stacked one upon another along the axial direction. 
     
     
         11 . The buoyancy module as claimed in  claim 1 , wherein three or more buoyancy modules are stacked one upon another along the axial direction. 
     
     
         12 . The buoyancy module as claimed in  claim 1 , wherein buoyancy elements have first and second faces directed along opposite axial directions, through which axially neighbouring buoyancy elements abut one another, the first and second faces being provided with axial registration features and the axial registration features on the first face of one buoyancy element being engageable with the axial registration features on the second face of another buoyancy element, so that through engagement of their respective axial registration features, axially neighbouring buoyancy elements register with one another and are thereby aligned with one another. 
     
     
         13 . The buoyancy module as claimed in  claim 12 , wherein the axial registration features include complementary male and female features. 
     
     
         14 . The buoyancy module as claimed in  claim 1 , wherein laterally juxtaposed buoyancy elements engage through lateral registration features to align laterally juxtaposed buoyancy elements with one another. 
     
     
         15 . The buoyancy module as claimed in  claim 1  further comprising at least one axially extending fastener passes through stacked buoyancy elements to prevent them from being separated from one another along the axial direction. 
     
     
         16 . The buoyancy module as claimed in  claim 15 , wherein the fastener includes a threaded member. 
     
     
         17 . The buoyancy module as claimed in  claim 1 , wherein each buoyancy element has a male interlocking feature on a first side and a female interlocking feature on a second side opposite to the first, and in which the male engagement feature of one buoyancy element interlocks with the female engagement feature of an axially neighbouring buoyancy element, thereby locking the two buoyancy elements together. 
     
     
         18 . The buoyancy module as claimed in  claim 17 , wherein the male engagement feature includes a boss and the female engagement feature includes a recess for receiving the boss. 
     
     
         19 . A buoyancy element for assembly into a buoyancy module which is for mounting on an elongate member to be deployed underwater and which has an axially extending passage to receive the elongate member, the buoyancy element having
 abutment faces on either side of a recess so that a two or more of the buoyancy elements are able to be laterally juxtaposed around the elongate member to encircle it;   upper and lower faces formed such that the upper face of one buoyancy element is abuttable with the lower face of an axially neighbouring element, to form a stack of buoyancy elements in which the recesses of the stacked buoyancy elements together form a through-passage for receiving the elongate member.   
     
     
         20 . (canceled) 
     
     
         21 . The buoyancy element as claimed in  claim 19 , wherein the upper and lower faces are provided with axial registration features and the axial registration features on the upper face of one buoyancy element are engageable with the axial registration features on the lower face of another similarly formed buoyancy element, so that through engagement of their respective axial registration features, axially neighbouring buoyancy elements are able to register with one another. 
     
     
         22 . (canceled) 
     
     
         23 . (canceled)