A spring applied band brake with hydraulic release is shown in figure 2. In the case shown, the brake is released by a hydraulic hand pump. To apply the brake, a valve is opened to release the hydraulic pressure. Winches with hydraulic drives can use the main hydraulic pressure to release the brake.
The handwheel is not used for routine operation. It is used to adjust the spring compression during calibration and to release the brake in case of a hydraulic malfunction. The handwheel should be secured with a seal after each calibration to prevent tampering. Alternatively, the brake screw can be equipped with a brake setting indicator to provide an easy visual check of the correct adjustment of the brake setting.
Figure 2: Spring applied brake with hydraulic release