A worker was killed instantly when a conveyor belt grabbed him and pushed him into a conveyor support. Multiple safety lapses, many related to a failure to view the conveyor as machine with potential hazards, contributed to the death. These failures are a common thread in the conveyor incidents discussed in the last two months (“Analyzing conveyor designs for safety,” Sept. 23, 2010; “When it comes to safety, conveyors are machines, too,” Oct. 21, 2010).
This avoidable death involved a conveyor at a recycling facility. The worker was solely trained to stand next to the conveyor, pick material off the belt, and sort it into one of several nearby barrels.
He spoke only Spanish, and all his previous work experience was in agriculture. He had never before worked with stationary mechanized equipment.
At the time of the incident, the conveyor belt was mistracking. The supervisor, who spoke little Spanish, instructed the worker to adjust threaded rods inside the conveyor frame that controlled the positioning of the conveyor belt bearing blocks and gave the worker a wrench for that purpose.
The worker adjusted the bearing blocks on one side and ducked under the conveyor to tighten the others. Staples holding the two ends of the belt together caught the hood of his sweatshirt and dragged him into a conveyor support. He was killed instantly.
As in the previous conveyor case I described, the incident could have been prevented with a functioning lockout/tagout plan. If the worker or supervisor had been trained in such a program, they would have known enough to lock out the conveyor before attempting maintenance. Mistake #1.
The worker was asked to do a conveyor maintenance job for which he was not trained. Because the task was new to him and was explained in a cursory manner, he was most likely unaware of the hazards of the job or how to protect himself from them. Mistake #2.
The supervisor did not ask the worker to verify that he understood the instructions, an especially important step in light of the language barrier between them. Mistake #3. And the supervisor should have stayed with the worker or assigned a partner to work with him instead of sending him to do the job alone. Mistake #4.
Because entanglement in the conveyor was a known risk, workplace rules should have prohibited loose clothing like hoods and ties that could catch on moving equipment. Mistake #5.
These training problems were compounded by oversights in the conveyor design. Workers or maintenance personnel should have been able to adjust the bearing blocks from outside the conveyor frame. Mistake #6. And instructions for safely performing this common task should have been printed on the machine. Mistake #7. Fixed guards should have kept workers away from hazards near the tail pulley and under the moving belt. Mistake #8.
Though conveyors seem mundane, slow moving, generally safe, and easy to understand, they can kill or cripple in an instant. Those who work with or around conveyors need proper training in the hazards of this work environment and how to avoid them. Conveyor manufacturers, companies that use conveyors, and employees who work with the machines are all responsible for preventing conveyor-related injuries.
Lanny Berke is a registered professional engineer and Certified Safety Professional involved in forensic engineering since 1972. Got a question about safety? You can reach Lanny at firstname.lastname@example.org.
Edited by Jessica Shapiro