Abstract: A drive system for use with a cable and a carrier for raising and lowering a payload includes a reel, a drive mechanism, a cable slack control mechanism, and a tension adjustment system. The drive member is operatively connected to the reel to rotate the reel in a winding direction when the drive member is rotated in a raising direction, and to controllably rotate the reel and/or permit the reel to rotate in an unwinding direction when the drive member is rotated in a lowering direction. The cable slack control mechanism is operative to automatically selectively decouple the drive member from the reel while the drive motor is rotating the drive member in the lowering direction when a tension on the cable does not exceed a threshold tension and/or the cable is fully unwound from the reel. The tension adjustment system is operable to selectively adjust the threshold tension.