I've seen a 1/16th scale toy gravity wagon, with part of the front side cut out, and the sides extended with plexiglass. It holds maybe a quart and a half of grain. But stick a small doll on top of the grain pile near the edge of the door, open the gravity wagon door, and it's not long before the doll is half-way submerged, then all the way submerged before the grain can run out. In fact, most of the time I've seen this demonstration, the doll reaches the bottom of the wagon and stops the flow of grain exiting through the door. The only problem is the top of the doll is still covered with grain.
I've seen it done with a one-eighth size grain bin and a doll, with a plexiglass plate on the front of the bin to watch what happens as grain flows out and sucks the doll down under the pile. And I've seen it on a large scale wagon, with the sides cut and replaced with plexiglass so you can watch, rather sickingly, as a child-size mannequin figure soon becomes trapped in the grain.
There are countless ways to demonstrate it. Bill Field and his staff use other methods at many of their exhibits at the Indiana State Fair and elsewhere, including letting people tug on a rope to see how much force they can exert against an object stuck under grain in a mock bin. The results are always the same. The grain wins every time. Perhaps nothing in nature is any more deceiving or any more deadly for the unsuspecting person than flowing grain.
Once you're up to your knees, you're trapped, notes Field, the Purdue University ag safety specialist. And once you're covered, which can happen in less than 60 seconds, you're likely going to suffocate and die. There have been survivors of such incidents, but they are rare.
All this is to make the point that as you're emptying bins here in late winter and into spring, think as many times as it takes to convince yourself it's not worth climbing into a bin with the auger clogged but running, to attempt to poke it free. A rope tied around your waist and a handheld two-way radio might help in some cases, but there are people no longer living who thought that was all the protection they needed.
Deaths in farm accidents in Indiana were up again last year. Percentage-wise, there likely weren't any more deaths from suffocation in grain bins than in other years, although Field and his staff have yet to analyze the data fully. But there was at least one. And one is one too many.
All the safety demonstrations in the world won't help if you don't take the message to heart. See, and believe! Grain has power if it's flowing.