Sizing Drop Weights for Deep Diving Submersibles Taking into Account Nonuniform Seawater Density Profiles

Abstract

This technical communication describes a method to size the drop weights used by submersibles for diving and surfacing taking into account varying seawater density profiles. The method allows consistent diving and surfacing performance to be achieved for differently sized submersible and target dive depths. The conditions that need to be met for safe operation of a submersible are described in this paper. The equations needed to appropriately ballast a platform and size its diving and surfacing drop weights are derived, highlighting some inherent limitations of using a two drop weight method for certain types of mission. The performance of the proposed approach is demonstrated through numerical simulations for different sized submersibles and target depths. The results show the effects of using different design parameters to illustrate some useful patterns and trends that can assist submersible developers and operators predict the effects of environmental and design uncertainties on important operational parameters such as the time taken for diving and surfacing.