Flexible-link towing is a physical process involving unsteady motion of inertia masses interconnected by a flexible element. Reliability of towing depends on selection of an optimum length of the towline and on minimizing the towline, overloads under various conditions. Non-automatic towing winches with a pull of 120 kN and above may be used with three-speed a-c cage motors controlled by means of magnetic controllers.
Taking account of the optimum speed ratio of the winches for towlines 37.5 to 48.5 mm in diameter use may be made of three-speed motors with a speed ratio of 1:2:4, developing a rated power and a rated pull at the medium speed; the motors are controllers.
