Elevator systems and methods of operation include a tension member support positioned within an elevator shaft, a tension member suspended from the tension member support within the elevator shaft, and a slack detection system. The slack detection system includes at least one biasing element housed within the tension member support and operably coupled to the tension member, the at least one biasing element arranged to receive a load from the tension member and a switch arranged to be moved from a first position to a second position in response to movement of the at least one biasing element, wherein when in the second position the switch triggers an emergency stop of an elevator car within the elevator shaft.