Hoist brake torque must be sufficient to safely hold the maximum load and handle the worst-case stopping scenario. Start by determining the load torque at the drum (load × drum radius), then account for reeving (parts of line), gearbox ratio, and mechanical efficiency to reflect the required torque to the brake’s mounting shaft. For many cranes, you must apply an appropriate safety factor because real conditions include shock loads, wear, and friction variation.
If the brake is used for dynamic stopping (not only holding), you also need to consider inertia: the rotating mass of the motor, gearbox, drum, and load reflected into the drive system. The brake must absorb stopping energy without overheating, so duty cycle (stops/hour) and stopping time are just as important as peak torque.
Because crane braking is safety-critical, the final selection should be validated against applicable standards and the crane’s duty class. If in doubt, provide application details to the brake manufacturer for verification.