Older silos and ladders were equipped with OSHA Approved Safety Harnesses. The cable system could be attached to the silo and allow service and maintenance people to safely travel up the ladder without fear of slipping or falling. The ladder could be one complete ladder from grade to the top. The system would only allow the operator to come down while activating a safety switch/button on the harness. The system would not allow any downward travel without this switch or button being activated. Parts and complete units are still available to satisfy OSHA requirements and give employees a safe way to service and maintain silos and vents.