Abstract :
High-speed winch deployment of cable-suspended deep-ocean instrumented payloads, as exemplified by the deep-ocean ship-deployed dipping sonar, requires unique solutions in the field of hydrodynamics, winch technology, and cable design. With the advent of deep-operating sonars, the desirability to minimize non-operating "dead" time by increasing deployment speed has became of paramount importance. Although the military must at present be considered the major proponent of this type of technology, future applications in the field of deep-ocean mining are anticipated. Bunker Ramo, under NAVSEA sponsorship, recently conducted a study and an at-sea demonstration test designed to both analyze and explore the feasibility of operating large horsepower winches at recovery and deployment speeds well beyond speeds normally associated with oceanographic operations. Presented in this paper are: (1) the hydrodynamic equations for deployment and recovery; (2) the unique relationship between cable specific strength, sensor weight, and deployment time; (3) methods for deployment, free fall versus powering down; (4) recovery options of constant tension or horsepower and when to change over for optimal recovery; (5) how to vary winch drag to prevent over-deployment; (6) the relative merits of both steel and Kevlar in the design of the EM cable; and (7) body shape selection and compromises made to achieve bi-directionat stability. Also presented are the results of deep sea tests and correlation of the test data with the computer models.
