Abstract: The invention is a device for controlling and adjusting the tension in the cable of mooring winches or cranes by measuring the torque exerted on a speed reducer having at least one intermediate gear-train, constituted of a pinion and a larger toothed-wheel integrally connected together. The device is characterized in that this intermediate gear-train rotates freely on two bearings supported by a stationary shaft concentric with the intermediate set, which stationary shaft is carried by two fixed supports located outside the bearings. The shaft also carries at least one pair of stress gauges secured between the bearings on two diametrically opposed generatrices of the shaft which are located in the same axial plane as the resultant compression force exerted on both bearings by the two tangential forces applied on the meshing teeth of the pinion and of the wheel of the intermediate gear-train.