More Guarding - Fewer Accidents?

When it comes to machine guarding, does more guarding result in fewer accidents? I have often wondered that. It might depend upon how you define ‘accident’. Is a mishap where no injury occurs considered an accident? How about if it results in damage to the machinery or the work piece?

I recall when lap seat belts in cars were first encouraged there was criticism that though the seat belts would indeed keep people from flying through the windshields it didn’t necessarily make them safer. The drivers and passengers would still bend forward and their heads would collide with steering wheels and dashboards. The seat belts have been upgraded since with a locking over-the-shoulder harness. Softer dashboards, front and side air bags have also been added.

These safe guards have made a difference in fatalities. In Minnesota, 85% of the drivers wear their seat belts. Of the car accidents that result in a fatality, upwards of 55% involve people who weren’t wearing their safety belt. That 15% of the population who don’t wear their seat belt provide a disproportionately high amount of the car accident fatalities.

So if the fatalities resulting from an auto accident are down, is the number of accidents as a whole down because of seat belt use? Are the minor injuries also reduced? Some experts theorized with the advent of seat belts that more accidents would actually result. They theorized that people would feel safer while wearing a seat belt and then feel more invincible, causing them to drive more recklessly. This recklessness might appear as driving at faster speeds or trying to multitask by also talking on a cell phone or hunt for a radio station while driving.

I have seen this theory affirmed when taking hikes with a Boy Scout troop. Most of the hikes the troop takes are along well defined paths. When walking on these trails, a scout feels relatively safe and doesn’t really pay much attention to where he is stepping. On these hikes the scouts will often stumble over the odd tree root or rock that they failed to notice. Sometimes this led to a minor twisted ankle. These are accidents but not serious or life threatening.

On a couple of occasions the troop has hiked over very rugged terrain. The scouts have climbed over rock falls where sharp ridges of rock are protruding, and where it would be very easy to twist an ankle. If they should happen to fall, a serious accident could result. During these hikes I noticed the scouts paid close attention to what they were doing. They stepped carefully, kept their arms out for balance and were prepared to catch themselves by reaching out and grabbing on to something to prevent a fall.

As a leader and an adult in a position of responsibility there would be lots of butterflies in my stomach during these hikes. I would imagine all the possible accidents that could occur. Fortunately, during these more dangerous excursions, accidents did not occur.

So how does this translate into the world of machine guarding? It stands to reason that installing guards on shop machines might not reduce the number of accidents, but would make them less serious in nature. The accident might result in a cut or scratch rather than a lost digit.

Thanks to Andy Goettsch