Depth Control System for Fatline Towed Arrays

The ability to control the depth of submarine towed arrays is a tactically desirable capability needed to place the array in the optimum acoustic layer. Discounting submarine maneuvers, there are three basic ways to implement array depth control: control array buoyancy, control tow cable catenary shape (via cable density variations and/or properly oriented lateral force devices), and/or fly the array via a depressor or winged appendages. The Phase I effort will consist of conceptual design and analysis of the two most feasible approaches: 1) controlling cable density, and 2) flyable approach, emphasizing the anticipated towing profile, practical limitations for typical fleet operations, cable termination designs, system reliability, low cost, and manufacturability of each. An overall performance and relative cost matrix will be developed that will identify the best near-term and long-term design approaches. The immediate near-term solution proposed for shallow water operations is a variable density cable consisting of a lightweight (LW) section near the array, preceded by a heavyweight (HW) section. The long-term "flyable" solution proposed uses the aforementioned LW cable to tow the array, which will include deployable, winged lifting surface devices with active controls yielding a completely flyable system with absolute +/- depth control.