Machine Guarding – Keeping Workplaces Safe
by Michael Shade, IQS Editor
I worked part time as a janitor when I was in college. One of my responsibilities was to keep each of the custodial closets and mechanical rooms in my assigned buildings clean and organized. This task was easy in the supply closets, because they were just closets. Their contents were limited to small amounts of bathroom supplies, maybe a mop and bucket and de-icer in the winter months. The mechanical rooms were a different story. These spaces served a dual purpose: storage as well as housing for HVAC components and controls, sprinkler controls and a number of other components. Some of these components were high voltage, some of them had moving parts and all of them were meticulously labeled and enclosed by machine guarding according to OSHA and other standards.
Image courtesy of Gordon Engineering.
One of the mechanical rooms housed a particularly bloated air handling unit that was outfitted with big belts that kept impellers spinning in their housing. The machine guarding for one of these belts stuck out into a space through which maintenance staff often had to walk to find replacement light bulbs. So many people had banged their heads against that guard over the years that we taped several layers of foam to its exterior in order to avoid causing increases in the school health insurance premiums. I can only imagine what kind of mayhem might have been wrought upon those premiums (and people’s heads) had the spinning belt not been covered by a machine guard.
Image courtesy of Flexbar Machine Corporation.
This is the main benefit of machine guards: they protect workers from becoming injured by equipment they use or work in close proximity to. A secondary benefit of machine guarding is that it protects equipment from nearby workers. As injurious as it would have been to my head had I smashed it against the spinning belt, it probably also would have disrupted the operation of the belt, which would have disrupted the air handling system, which would have affected air quality in the building, which would make repairs necessary, which would probably be expensive. Machine guards are simple yet indispensable utilities that head off accidents of that nature.
Machine guards are designed in all kinds of configurations. Because there’s such a variety of equipment in use throughout industry, commerce and in institutional settings, it probably would be impossible to put together a complete list of every machine guard variety. Some varieties are more common than others, though. Machine guard fencing, for example, is a simple, effective way of keeping workers and hazardous equipment separate from each other except when necessary. They also limit access by unauthorized people and in doing so limit liability in the event of accidents. Lathe guards, drill press guards and chuck guards, on the other hand, each are used in very specific processes. A lathe guard keeps the shavings and flung debris from a lathe workpiece from flying about and injuring workers. Drill press guards keep digits and appendages from accidentally coming into contact with drill components. These kinds of tools also make debris management easier, which makes workspace maintenance easier. Well-maintained workspaces tend to be safer and healthier working environments, so machine guards can contribute to worker well-being in this way as well.
The best thing about machine guards is their simplicity. A chuck guard, for example, can be a simple as a piece of transparent plastic fastened to equipment with screws and brackets. Machine guard fences can be simple wire constructions. The belt guard on the air handling equipment in the mechanical room was a simple aluminum cover. Despite their simple design and low cost, each of these utilities eventually will recoup their cost many times over in the form of medical bills that were never incurred and operational downtime that never became necessary. Machine guards will always play an important role in all of the contexts in which they’re used.