Of all the dangers involved in unloading grain bins, grain entrapment is indisputably one of the most perilous.
A routine entry into a bin to shovel some resistant grain can become deadly in a matter of seconds if the auger — and thus the flow rate — stays active.
“One of the main things we need to realize about grain handling is that flowing grain behaves like quicksand,” said Robert Gobeil, a grain bin safety expert.
“It only takes a few seconds to sink past your knees — and once you’re past your knees at the grain level you’re basically trapped. You cannot self-extract and get out on your own.”
The survival rate when trapped in grain is extremely poor — it’s estimated the fatality rate is 90 to 95 per cent.
But the risks of entrapment can be easily minimized. And that starts by not working alone.
“One of the most basic things producers can do is have an attendant standing on the outside of the bin who can power down and lock out equipment so it can’t accidentally be turned back on during the rescue process,” said Gobeil, an agricultural health and safety specialist with the Canadian Agricultural Safety Association.
Augers help create the quicksand effect — one moving 100 bushels a minute only takes a second or two to move a human-sized volume of grain.
Another major cause of grain entrapment is poor aeration in the bin, said Gobeil.
“When grain is out of condition it tends to crust up and create a bridge across the surface — usually about a four-inch-thick layer. So when you run your flow systems you can create a void below the grain. When someone goes on top of this bridged, crusted material, they can get trapped.”
(The Prairie Agricultural Machinery Institute has done extensive research on grain conditioning. For more information, visit www.pami.ca and enter “aeration” in the search box.
Although intended to prevent falls, harnesses specifically designed for grain bins can prevent someone from sinking into the grain vortex. But many older bins do not have the anchor points necessary to secure the harness — at least against a fall. However, if you’re using the harness primarily to prevent sinkage (which puts less pressure on anchor points), there is some room for improvisation.
“Farmers are pretty crafty guys,” said Gobeil. “They can easily find an adequate anchor point to create a fall restraint system.”
‘It won’t happen to me’
For the past two years his association has been taking its BeGrainSafe mobile unit (which demonstrates how quickly a person can become entrapped) to trade shows, exhibitions and other farm events.
“A lot of people are really surprised how quickly an entrapment can occur,” said Gobeil. “They have a lot of stories about how they used to play in grain when they were kids or go into the grain bin and shovel to clear up augers.”
But others are harder to reach.
“At the other end of the spectrum we have a lot of people who have the ‘It won’t happen to me’ mentality. A lot of the ones with that mentality are typically the more experienced producers. They’re aware of the dangers, of course, but they have not had it happen to them yet.”
Grain bin manufacturer GSI has come up with a self-emptying grain bin system that uses inflatable liners to essentially push the grain towards the auger.
The company claims the system can clear out almost 100 per cent of the contents of a flat-bottom grain bin without manual labour or use of a sweep auger.
Using automatic touch screen control, the system inflates one of two liners — one for each half of the bin — which gently push grain towards the centre of the bin and the auger. The process is then repeated on the other half of the bin.
Some producers ask how susceptible the liners are to breakage from inflation or mouse activity, said Jonathan Waits with GSI’s head office in Illinois.
“The system works using very little air pressure – you’re looking at less than one psi throughout the entire process,” he said. “There’s enough capacity in our blower system to overcome most holes in the liners so you still have the air pressure needed to empty the remaining grain.
“Once you’re done with that process you can clean and patch the liners. They are easily fixed — you just clean them off and it’s a simple glue patch to fix any holes.”
“It looks like quite the interesting system and would definitely be a step in the right direction,” said Gobeil. “If we can reduce the frequency of people going into bins in general it’s that much less likely for an entrapment to occur.”