A variablebuoyancy systemfordeep ocean vehicles

A variable buoyancy system hasbeendeveloped for underwater vehicles operating deepintheocean. Thispaper reports onthedesign, testing anddevelopment ofthesystem. The system wasdesigned tochangebuoyancy atupto11/min ata depth downto6000m. Theresults showedthatthesystem worked atitsdesign specifications after modification butthatfriction losses resulted inarelatively lowefficiency ofaround35% atlow working depth, butefficiency increased withincreasing depthto about70%at6000m.Efficiency couldbeincreased further with redesign orwithchanges inspecification. IndexTerms-AUV,ROV,variable buoyancy, variable ballast