An apparatus includes a drum to draw in or let out a line and a motor and transmission coupled to the drum to apply a torque thereto. The transmission includes at least one stage of gearing to reduce a gear ratio of the motor relative to the drum. A shaft couples the motor to the transmission and a locking mechanism selectively locks the shaft to prevent rotation of the drum. In certain embodiments, a braking mechanism may be provided in addition to the locking mechanism to slow the motor when the motor is not applying torque to the drum. This may slow the motor sufficiently to enable engagement of the locking mechanism.