Most of North Dakota is experiencing a severe drought. NDSU Agriculture has assembled important resources for dealing with the drought. Access them now. 

Page Title

Grain Bin Safety

Body

Grain Bin Safety

Working in and Around Grain Storage and Silo Enclosure

(Photo by C.S. Hagen used with permission of The Forum).

(Photo by C.S. Hagen used with permission of The Forum).

People often need to work in and around grain bins and other storage and enclosed facilities. Many times, this happens when there is grain stored in these facilities, which makes the job a greater hazard for the people doing the work. These tasks may include maintenance on the equipment, cleaning the equipment, and dealing with grain has gone out of condition and is stuck in the bin.

Here are a few tips to stay safe while working in and around these structures.

First, decide if the task is necessary now while there is still grain in the structure. Can the maintenance be done later when the structure is empty?

If the work is needed now, plan how to safely go about carrying out the tasks.

Let everyone on the farm know that there will be people working around the grain storage structures and that no one is to start any equipment at the site.

Assemble a team that will work on these tasks and assign each person their duties. Working in these structures is at minimum a two- to three-person job. At least one person needs to be outside the bin and to be able to hear the individual inside the bin. Station one individual on top of the bin who can always see the person in the bin. This individual can react quickly if something goes wrong. If a third person is on the ground, that person can call 911 and get help. They can direct emergency personnel when they get to the location and give them a rundown of what has taken place. The person on top of the bin stays there, watching the person and communicating with the person in the bin.

Watch this video from the National Corn Growers Association and National Grain and Feed Foundation for more tips for avoiding grain bin entrapment.

Remote video URL

Prior to entering the enclosure, run the aeration system and open the top of the bin for at least an hour to help remove any toxic gas levels.

Before entering, take a gas reading to make sure the gas levels are safe.

When the team is ready to go to work, tag out and lock out all grain handling equipment. This helps prevent accidental operation of this equipment while working inside.

The person entering the enclosure needs to be in a safety harness that is secured to the outside of the bin.

Grain handling in bins can become routine and when a worker is in a hurry an accident can happen. Sadly, year after year, people who enter grain bins are trapped and engulfed in grain resulting in suffocation. The number of grain bin fatalities can be greatly reduced if farmers and their workers get proper training and follow grain bin safety procedures in the video below. This is a longer, more detailed version of the National Corn Growers Association and National Grain and Feed Foundation video referenced above.

Remote video URL
Sections

Caught in the Grain!

(AE1102, Reviewed Feb. 2019)

People can become caught or trapped in grain in three different ways: the collapse of bridged grain, the collapse of a vertical wall of grain, and entrapment in flowing grain. Moving or flowing grain is involved in all three. People who work with grain – loading it, unloading it, and moving it from bin to bin – need to know about the hazards of flowing grain and how to prevent a grain entrapment situation.

Revised by Kenneth Hellevang, Agricultural Engineer

Availability:Web only


How It Happens

People can become caught or trapped in grain in three different ways: the collapse of bridged grain, the collapse of a vertical wall of grain, and entrapment in flowing grain. Moving or flowing grain is involved in all three. People who work with grain – loading it, unloading it, and moving it from bin to bin – need to know about the hazards of flowing grain and how to prevent a grain entrapment situation.


1. The Collapse of Bridged Grain

Grain can become bridged when it is moldy, high in moisture content, or in poor condition. The kernels stick together and form a crust which may be self-supporting. This gives a false indication that it is safe to stand on the surface of the grain. The worker cannot tell if there is grain under the crust or not.

A hollow cavity will form under crusted grain when some of the grain has been removed from the bin. The surface over this cavity is not strong enough to support the weight of a person. As the person walks onto the grain, the bridge of crusted grain will collapse. The victim instantly falls into the cavity along with the grain and is usually buried under several feet of grain. It will be very difficult to determine exactly where the victim is.(See Figure 1.)

Hollow develop under crusted grain

Figure 1. A hollow may develop under crusted grain when grain is removed from the bin, forming a bridge of grain. When the bridge collapses under your weight, you will be buried in seconds.

Safety Precautions:

  • Is the grain bridged? Stop the auger and do not go in the bin. Instead, look for a funnel shape at the surface of the grain mass after some grain has been removed. If the surface of the grain appears to be undisturbed and has not funneled down toward the auger, then it has bridged and there is a cavity under the surface. The cavity will be equal in volume to the grain removed from the bin.
  • Do not enter the bin to break the bridge loose or attempt to stand on the grain. From outside of the bin, use a pole or other object to break the bridge, causing it to collapse. Tie the pole or other object to a rope which is tied to the bin so you can retrieve it if you drop it.
  • If the surface is disturbed and shows evidence of the grain flowing down to the auger, then a chunk of crusted grain has probably moved down to the auger and blocked off the flow of grain. This situation is dangerous if you enter the bin, because the grain at the top of the funnel will break loose and avalanche down.
  • Prevent grain bridging by storing grain in good condition and avoiding spoilage, which leads to crusted grain.

2. Collapse of a Vertical Mass of Grain

Grain can “set up” in a large mass against the bin wall or in various formations when it has been stored while in poor con-dition. The mass of grain can collapse and “avalanche” down on workers who attempt to break it loose with shovels or other objects. There will be no warning when it breaks loose and cascades down. The impact will knock workers off their feet, burying them in various positions. Individuals working in the bin can be buried almost instantly.

If secondary avalanches are possible, it will be very risky for rescue personnel to dig out the worker. The rest of the grain will have to be stabilized or knocked down so it is safe for rescue personnel to work.(See Figure 2.)

Watch for unstable grain

Figure 2. Grain may stick together when stored in poor condition. After some of the grain has been removed, some of it may remain stuck together in a large pile or lump. Breaking it loose can be very risky. You may be buried in seconds when it cascades down.

Safety Precautions:

  • Do not enter a bin and try to break down grain which has “set up” in a large mass.
  • Attempt to break up the grain mass either from the top of the bin with a long pole on a rope, or from outside of the bin, through the door, with a long pole. Entering the bin to do this work can cost you your life!
  • Expect, and be prepared for, the grain mass to break free at any time and to cascade down.
  • Prevent grain from “setting up” in the bin by storing grain in good condition and avoiding spoilage which leads to this problem.

3. Flowing Grain

Flowing grain will not sup-port the weight of a person. It will pull a person down and into the grain mass as it flows. The “suction” action is strong enough that a person cannot “swim,” climb, or walk against it and get out. As grain flows out of a bin the victim will be pulled down and under very quickly with little or no time to react.(See Figure 3.)

Flowing grain pull on body

Figure 3. Flowing grain can exert a tremendous pull on a body caught in the flow. You will be helpless within three to four seconds. In 20 seconds or less, you can be completely buried.

A person cannot be pulled from flowing grain without risk of injury to the spinal column if the grain is at waist level or higher. The grain will have a very strong grip on the body. Research has shown that up to 400 pounds of pull is required to extract a body from waist-deep grain.* That is more than enough force to permanently damage the spinal column.(See Figure 4.)

Use a life line to enter a grain bin

Figure 4. Use a life line if you must enter a grain bin! Always stop the machinery, first! Remember, a life line improperly used can cause injury to the spinal column. Install a permanent life line in each bin.

Dangerous flowing grain situations are: grain flowing downward in a bin; grain flowing downward out of a rail car, truck or wagon box; and grain flowing downward in an auger-pit. Workers should not enter any of these containers when the grain is flowing.


Safety Precautions:

  • Children should not be permitted to work or play in an area where there is flowing grain. It is an attractive nuisance and is dangerous to people of all ages, especially children.
  • All workers involved in situations where there is flowing grain should be warned to stay out of the grain.
  • Warning decals should be placed at all bin entrances, on all rail cars, truck and trailer boxes used for grain hauling, and on all gravity discharge wagons.
  • Never enter a grain bin without stopping the auger first and then using “lock-out/tag-out” procedures to secure it. Use a key type of padlock to securely lock the switch for the auger in the off position. Attach a tag to the locked switch so that other people involved can positively identify it.
  • Never enter a grain bin alone; have at least two people at the bin to assist in case problems arise. Use a safety harness or safety line when entering the bin.
  • Install a permanent life-line hanging from the center of the bin for a person to grab on to. Tie slip-reducing knots about one foot apart along the life-line. A life-line in a grain bin does not make it safe to enter the bin and should not lead workers to taking undue risks because of a false sense of security. Life-lines are commercially available through safety equipment retailers.
  • Control the access to grain storage facilities to prevent grain entrapments.

Rescue Procedures

  • Shut off all grain-moving machinery. Stop the flow of grain!
  • Contact the emergency rescue service or local fire department.
  • If possible, ventilate the bin using the aeration or drying fan.
  • Protect the rescue workers; be sure the power to the auger is locked out, and use safety lines and respiratory protection.
  • Work in such a way that additional grain pressure is not exerted on the victim.
  • Use retaining walls around the trapped person. Form retaining walls with plywood, sheet metal, or other structural materials to keep grain from flowing to the victim.
  • Remove grain from around the victim using shovels, buckets or a vacuum.
  • Cut at least 2 holes in bin sides to drain grain away from the victim if the person is completely submerged. Cut at least two V-shaped or U-shaped holes on opposite sides, or more holes equally spaced around the bin, using a cutting torch, metal-cutting power saw, or air chisel. The bin will collapse if it is not evenly unloaded.
  • Apply care to the victim as soon as possible, providing breathing assistance, maintenance of body temperature, and emotional support. Plan ahead for victim removal procedures.
  • Don’t give up when conditions appear to be grim. People have survived submersion in grain for up to two hours; sometimes the victim can still breathe while buried in the grain. Never give up!

References:

  1. Grain Bin Entrapment: What If It Happens To You?, Jim P. Allen, Extension Engineer and Ronald T. Noyes, P.E., Extension Agricultural Engineer, Oklahoma Cooperative Extension Service, Division of Agricultural Sciences and Natural Resources, Oklahoma State University, 1994.
  2. C.V. Schwab, I.J. Ross, L.R. Piercy, B.A. McKenzie (1985). Vertical Pull and Immersion Velocity of Mannequins Trapped in Enveloping Grain Flow. Transactions of the ASAE Vol. 28(6).

February 2019


Trapped in Grain Bin

Steps to Take for Rescue When Trapped in a Grain Bin

Grain Bin dangers

Check out the quick tips below. For more in-depth information, see the full NDSU Extension publication"Caught in the Grain!"

If you come upon a grain engulfment, shut off all equipment around the bin site and turn off the electric power to the site.

  • Call 911 immediately and indicate that it is a possible grain bin engulfment so emergency rescue can bring the appropriate equipment for extraction.
  • Do not attempt to enter the grain bin alone to try to save the individual.& You are putting yourself in harm’s way and may endanger the individual who is trapped even more.
  • If an individual is completely engulfed in the grain, you may want to turn on the bin aeration system to help get air to the trapped person. However, if it is cold out, turning the fans on may result in the trapped person getting hypothermia.
  • If an individual is completely engulfed, you may want to open the sides of the grain bin to start the grain flowing out to speed the recovery process. You can achieve this by using a loader bucket, cutting torches or metal cutting saws to cut out U- or V- shaped holes equally spaced around the bin. This will allow the grain to flow evenly out the sides and prevent the bin from collapsing on top of the trapped individual.
  • If the individual is trapped in grain but not fully emerged, stay where you can visually see the person and continue communication to keep the individual alert and responsive.
  • Do not go in by yourself to rescue the individual as you also may get trapped or you could cause the trapped individual or yourself to become completely submerged in the grain.
  • Once help arrives and safety harnesses are in place and tied off, rescuers can begin to enter the grain bin to rescue the trapped individual. The rescue team will need to build a wall around the trapped individual so they can start removing grain from around the trapped individual and the wall will keep the grain from flowing back on Rescue teams need to have someone outside the bin who has a visual of what is going on so if a problem occurs that individual can react and call for additional help if needed.
  • Do not attempt to pull an individual from trapped grain as the force of the grain pushing down on the person can cause severe bodily damage, which could include spinal column damage.
  • Once the individual has enough grain removed around him or her, secure a safety harness so the person won’t sink deeper into the grain.
  • Once the trapped individual is free, he or she can be raised up and taken to safety for medical evaluation.