Volume
3 Issue
11
August
1, 2006
Grain Combine Fires - Still a Burning Problem
It's a perfect day to start wrapping up the last full week of a
long, busy harvest. There's not a cloud in the sky. The crop is dry
and bountiful. The harvest has been as hectic as any other, but
fortunately with no breakdowns or any real problems! In fact, other
than checking the oil a few times, greasing bearings, and fueling
up, your combine hasn't missed a beat. You're congratulating
yourself, because this year . . . you'll be done with harvest before
all your friends and neighbors.
As you turn at the end of the field, midway through your first
round, you smell smoke. You feel your stomach sink. That feeling of
anticipation and exhilaration turns to fear and you realize that
last busy week of combining could drag on into the early winter!
You jump out of the combine wishing you were closer to the cell
phone and fire extinguisher in the cab of your pickup! Just as you
hit the ground, you turn back to see bright orange flames and smoke
starting to pour out of the bottom of the combine's engine
compartment. You walk toward the smoke to get at the engine to try
and at least throw some dirt on it. You burn your hands on the now
red-hot hood latch and resign yourself to standing back and watching
your $250,000 new machine go up in flames!
Does this scene sound far-fetched? Probably not to most busy
farmers. University of Minnesota research show that combine and
tractor fires still cause millions of dollars in property losses
each year and even more because of lost time and downed crops during
the busy harvest season. Fires not only cause huge losses and waste
time...they also cause dozens of injuries each year, and
occasionally a person is killed because of a farm machinery fire.
There are two keys to preventing a disaster like the one just
described:
- prevention
- preparation in case a fire does break out
Machinery Fire Prevention
For a fire to occur, three things must be present: air, a material
to burn, and a heat source. It's impossible to eliminate air around
a farm machine. So, machinery fire prevention focuses both on
keeping the machine clean of possible fire-causing materials and
eliminating all possible sources of heat that could lead to a fire.
Cleanliness and Maintenance
Begin every harvest season with a clean machine. Pay special
attention to the engine and engine compartment, since research
indicates that over 75% of all machinery fires start in that area.
Use a pressure washer to remove all caked-on grease, oil, and crop
residue. A clean engine will run cooler, operate more efficiently,
and greatly reduce your chance for fire.
After starting the season, make sure you frequently blow any dry
chaff, leaves, and other crop material off the machine with
compressed air. Also, clear off any wrapped plant materials on
bearings, belts, and other moving parts.
Pay close attention to your machine operator's manual and follow
all instructions and schedules for lubrication and routine
maintenance. If you notice leaking fuel or oil hoses, fittings, or
metal lines, make sure to replace or repair them immediately!
Eliminate Heat Sources
Combine and tractor fires can be caused by several heat sources. The
most common is exhaust system surfaces that contact flammable
material. Make sure your exhaust system including the manifold,
muffler, and turbocharger are in good condition and free of leaks.
When checking your oil and performing other daily maintenance,
quickly scan any exposed electrical wiring for damage or signs of
deterioration. Replace any worn or malfunctioning electrical
component with proper parts from your dealer. If you are blowing
fuses, or have a circuit that intermittently cuts out, it's a good
sign that there's a short or loose connection in the system. The
arcing electrical wires on a farm machine will generate extremely
high temperatures.
Also keep an eye out for worn bearings, belts, and chains. A
badly worn bearing can glow red-hot. Rubber belts subjected to
intense heat from a worn part can burst into flames.
Be Prepared for the Worst
Despite your best intentions and good maintenance, a fire on a
combine or tractor can still occur. Your best source of protection
for a combine is at least one fully charged ten-pound ABC dry
chemical fire extinguisher. A five-pound unit is recommended for
tractors. Select only extinguishers with an Underwriter's Laboratory
approval. Having two extinguishers on the machine is even better in
case one malfunctions or loses pressure.
Keep one mounted in the cab, and one where it can be reached from
the ground. Check your extinguishers periodically, paying special
attention to the pressure gauge. To function effectively, the gauge
must show adequate pressure to expel the powder inside.
Extinguishers should also be checked periodically by someone from
your local fire department or insurance company. Any extinguisher
that has been even partially discharged must be fully recharged
before it's used again. During even a brief discharge, the tiny dry
chemical particles will create a small gap in the internal seal of
the extinguisher valve. This tiny opening will cause any remaining
pressure to leak out in a few hours or days.
What If I Have A Fire?
If a fire does break out on a machine you're operating, quickly shut
off the engine, grab your extinguisher, get out, and get help. If
you forget to grab the extinguisher, don't go back in after it
unless the fire is small or confined to an area well away from the
cab.
Having a cell phone or two-way radio nearby will help get
professional assistance to the field more quickly. Be sure to stay
calm and give complete and accurate directions.
Approach any fire with extreme caution. Even a small fire can
flare up dramatically as you open doors, hatches, or other areas to
gain access. These types of fires are especially dangerous when
liquid fuels are involved.
If possible, use the extinguisher's flexible hose to shoot the
chemical from a safe distance at the base of any flames you see.
Continue to blanket flames to allow the fire to cool and prevent a
reflash.
Remember that it may not be possible to put out every fire. If
it's in a difficult-to-reach area or seems out of control, don't
risk the chance of injury or even death... wait for help to arrive.
Before resuming operation after any fire, make sure to find and
correct the cause. It’s always best to have the machine looked at by
a qualified equipment mechanic who can also help to prevent future
fires by locating parts that need replacement and inspecting other
areas that might represent a future fire hazard.
*for more fire protection information:
http://www.safe-design.net/machinery_fires/index.html
John M. Shutske
Agricultural Safety & Health Specialist & Professor
Department of Bioproducts and Biosystems Engineering
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