Ship velocity measuring system using dynamometer - detects resistance of body trailed in water behind ship and provides direct read=out in accordance with drag

摘要

The system uses a dynamometer with a fixed element secured to the ship and a mobile element secured to a body trailed through the water. The two dynamometer elements are coupled together via a number of springs allowing a square relationship to be obtained between the force exerted on the mobile element by the resistance of the trailing body and the displacement of the mobile element relative to the fixed element of the dynamometer. Pref. the mobile element is coupled to the trailing body by a cable. Pref. the two dynamometer elements comprise two tubular elements fitting one inside the other, the fixed element having a linear velocity scale along which an index attached to the mobile element can move, so that a direct read-out is obtained.