A 43-year-old worker at a cement manufacturer died from injuries he received when his right arm became entangled in an auger conveyor. Why? Because there were no guards, no lockout/tagout and poor training.
Investigators with the U.S. Mine Safety and Health Administration (MSHA) found that the mine operator failed to properly guard dangerous machinery, ensure lockout/tagout rules were followed and adequately train miners on safety protocols.
Job included monitoring machine with history of problems
On July 21, 2022, Travis Cason arrived at 6:46 a.m. to begin his shift at the Giant Cement Company in Dorchester County, South Carolina. Giant Cement removes marl, an unconsolidated sedimentary rock consisting of clay and lime, from a surface mine and processes the substance into cement.
Cason was a shift utility worker with 47 weeks of mining experience. His job duties included housekeeping tasks and walking through the mine’s finish mill area to make sure machinery was working properly.
Shift utility workers were also assigned to monitor the mine’s auger conveyor, a machine with a history of maintenance problems, to confirm it was functioning properly.
Conveyor was going to be replaced
The auger conveyor was installed horizontally 48 inches above the floor, was more than 28-feet long and had a 10-inch diameter auger that rotated inside a trough, which conveyed material as the auger turned. The entire length of the conveyor was designed to be covered by guards held in place by spring clamps. In addition to the maintenance problems, material would clog at or in the machine’s discharge pipe, so an air lance was installed for shift utility workers to use to clear blockages.
The mine operator considered replacing the auger conveyor in August 2021, but later decided to just repair it anytime it broke down. The mine’s maintenance manager put a work order in to fully replace the machine in June 2022, but that work hadn’t been started.
Workers heard scream but there were no witnesses
At 9:30 a.m., Cason was instructed to verify that an air compressor was operating properly and then use it to air-lance dust from underneath the mill’s feeders. Twenty minutes later, several other workers heard a distress call over the radio. One of the workers called Cason on the radio to check in, but Cason didn’t answer.
At around the same time, a contractor crew working near the finish mill heard someone scream. The crew stopped working to investigate and found Cason lying on the ground in front of the doorway to the mill, having descended the stairs from the third floor of the facility.
One of the contractor crew members contacted the mine operator while the others began administering first aid.
There were no witnesses to the incident.
At 10:02 a.m., 9-1-1 was called with emergency medical personnel arriving on scene at 10:22 a.m. Cason’s right arm was amputated due to injuries apparently sustained from entanglement in the auger of the auger conveyor. He was transported to a local hospital where he died from his injuries at about 11:31 a.m.
Lack of training, guards, lockout/tagout protocols caused fatality
MSHA investigators found that while Cason had completed all of his required safety and task training, his training on workplace examinations was dedicated to correctly filling out inspection forms. Adequate training on workplace examinations would have included training on:
- hazard recognition techniques
- requirements to alert others to hazards found, and
- how to document hazards that weren’t immediately corrected.
While shift utility workers were considered competent persons to conduct workplace examinations at the mine, investigators found that exams either weren’t conducted or weren’t documented and miners weren’t notified of uncorrected hazards. Miners told investigators that the reasons these exams stopped was because they would document hazards but those same hazards would remain uncorrected, so they stopped documenting them.
The lack of proper training on workplace examinations and failure to adequately document and perform workplace examinations contributed to the fatal incident.
The mine operator’s failure to ensure the auger conveyor was properly guarded and that lockout/tagout procedures were followed also contributed to Cason’s death.
Investigators determined that spring clamps used to keep the auger conveyor’s guards in place were loose and inconsistently spaced along the length of the machine. Some guards were missing, exposing miners to entanglement hazards.
Shift utility workers were told to look at the ends of the auger shafts to ensure the shaft was rotating. This was done by separating guard sections to expose the moving parts. Investigators found that it was common practice to do this without de-energizing the equipment first and to generally run the auger conveyor without having the guards in place.
Mine removed conveyor, developed rules to address deficiencies
MSHA stated that four root causes led to Cason’s death, including the mine operator’s failure to:
- assure that the guard for the auger conveyor was in place while the conveyor was in motion
- de-energize and block machinery and equipment against hazardous motion before performing maintenance
- perform adequate workplace examinations, and
- provide adequate training to miners for tasks in which they had no previous experience.
The mine operator has since permanently removed the auger conveyor from service and doesn’t plan to replace this equipment. Miners have been trained to ensure all guards are secured in place while any equipment is in operation.
Written procedures were developed requiring a supervisor and electrician to verify machinery and equipment is de-energized and blocked against hazardous motions before maintenance work can begin. Procedures and a tracking system were also developed to assure workplace examinations were properly completed.
Additional task training was completed for all miners for each assigned task within the mine to address the general lack of training. This training included:
- guarding
- construction and maintenance of guards
- illumination
- safe means of access
- safety defects on equipment, machinery and tools
- maintenance and repair of equipment and machinery, and
- workplace examinations.
The mine operator said it will also provide task training for each new task assigned to miners.