Maximum Safety Guarding in Medium Security
The federal government takes safety seriously. This is true in the Capitol, in the military — and in U.S. medium security federal prisons.
Many prison work programs incorporate manufacturing processes designed to provide inmates with job training that they can use upon release, as well as being a productive activity during incarceration. As with any production line, these programs must meet rigorous safety demands and employ safety guarding solutions that protect workers.
Richard Greene recently had the opportunity to help evaluate and increase safety in one such program at the United States Penitentiary at Marion in Illinois.
Evaluating the risks
The federal prison recently introduced new machines for wire hanger manufacturing. Electrical supervisor Ryan Humphries, who works for prison contractor Unicor, recognized that these machines were in need of a risk assessment. Having worked with Richard Greene territory manager Tom Wentz in the past, Humphries knew that the Richard Greene Company could help.
Wentz, in consultation with Humphries, identified potential hazards related to the new machines, evaluating both the severity and likelihood of risk. He spoke with the inmates about how they run the machines: where they stand, where their hands are, how often they need to reach into the machine, and so on. He identified “pinch points” — places where fingers could be injured. Wentz also noted which parts of the machine might need special treatment and how long moving parts would need to stop in the case of a potential injury.
After the assessment, the team determined that the machines were “Category 3” systems. The machines pull wire from spools, twist and form the wire into hangers, cut off the wire, and slide the hangers out onto a bar and into a bin. Jams and misfeeds are not uncommon, so completely preventing workers from reaching into the machine was not practical — but protecting them when they did so was vital.
First, hard safety guarding was needed to block the back of the machines and prevent anyone from reaching into a machine from that side. With only the front of the machine accessible, Wentz suggested “light curtains.” This Category 4 control system stops the machine if something breaks a light beam and prevents restart until the object — in this case, a worker’s hand — is removed from the hazard area. This is where the first unique issue came into play.
“The metal bar that that comes out from the machine to hold the hangars will always break the light curtain,” Wentz explained, “and when hangers slide through onto the rod, they also break the beam. We chose a system with a few features that allow ‘fixed blanking.’ We can configure the system to know that a beam will always be blocked by an object so that it doesn’t shut off. We also implemented ‘floating blanking,’ in which two beams can be blocked for a short period to accommodate a timed exit of so many milliseconds.”
Next, Wentz calculated stopping time to determine where to mount the curtains. Using machine specs and the Occupational Safety and Health Administration (OSHA)’s published hand-speed constants, the team established the time between when the machine would be notified of a curtain break and when moving parts would actually come to a complete stop. Wentz made sure the settings were compliant with OSHA, European standards, and other regulations.
“You can’t just look at a standard and say, ‘This is what we need to follow,'” Wentz says. “You need to look at each individual machine and see how it operates, how the operators run the machine, and then take the necessary steps to reduce risk as much as possible.”
Making security safer
Once the solution was designed, the team proceeded with testing, validation, and documentation of the new safety guarding devices. Wentz made sure to monitor the operations of the machine, reassessing the safety features and adjusting them as necessary.
Training is an essential part of the safety process, as workers often modify or even override processes that they feel slow them down or otherwise inconvenience them. Proper instruction as to why the safety processes and devices are in place, and how to work with them most effectively, is a necessary part of any installation.
Finally, the prison staff then had OSHA come to check the first machine. Upon approval, they then upgraded the others. The final result: a safer environment for prisoners as they perform a job that offers a measure of dignity and productivity that’s critical to their wellbeing.
Evaluating and adding safety features, especially to new equipment, is not always an easy decision, but for the Marion prison, the safety of the inmate workers prompted this important action.