Storing and handling large volumes of grain or feed on farms is very common. Grain storage structures
and handling equipment create hazardous work situations. Workers who work with grain – loading,
unloading, or moving – must be aware of the hazards of flowing grain and ways to prevent a grain
entrapment situation. Workers can become caught or trapped in grain in three different ways:
Entrapment in flowing grain
A grain bridge collapse
The collapse of a vertical grain wall
Flowing Grain Hazard
Flowing grain is a term that is used to describe the movement (downward and out) of grain from a
storage bin. During unloading, grain flows in a funnel-shaped path downward to the unloading auger. A
conveyor at the bottom of the bin transports the grain out of the bin. This vortex of grain behaves very
much like a water whirlpool. Velocity increases as grain flows from the bin wall at the top of the grain
mass into a small, vertical column at the center of the bin.
Flowing grain acts very similar to quick sand. If a
worker is pulled under, there is often little or no time
to react (see Figure 1). Rate of inflow at the center top
of a grain bin is so great that escape is impossible.
Once engulfed in the grain flow, a victim is rapidly
drawn down toward the bin floor. The few survivors
of this type of entrapment say they deliberately
covered their mouths and noses with their hands and
did not panic. All expressed amazement at the
tremendous speed of their engulfment.
Source: North Dakota State University Agriculture
and University Extension
Figure 1: Flowing grain
FLOWING GRAIN ENTRAPMENT
WSPS.CA
