Dry field conditions increase combine fire risk
Warm, dry weather and early maturing crops are good for helping field dry grain, but increase the risk of combine and field fires.
With list prices of new combines with a grain head in excess of $350,000, operators will want to not only prevent fires before they start, but be ready to handle them once they occur. It's not unusual for millions of dollars of combine losses to occur throughout the Midwest when conditions are dry. Fuel sources, such as leaves, stalks, husks, dust, oil and fuel and ignition sources, including exhaust, bearings and electrical wiring, are always present when harvesting fields.
Combine operators can help minimize losses by preparing themselves for harvest when conditions are dry.
• Carry a minimum of two class ABC fire extinguishers: a smaller 10-lb. unit in the cab and a larger 20-lb. extinguisher at ground level on the combine plus one additional extinguisher on each motorized piece of equipment used in the field (farm tractors, semi tractors, pick up, etc.). Invert the extinguishers once or twice a season and shake them to ensure that powder inside the extinguisher hasn't been compacted together by machine vibrations.
• Arrange to have tillage equipment present within the area during harvest. In the event a fire should occur this equipment may allow farmers to create a barrier around the perimeter of the field to prevent fire spreading to adjacent fields.
• Equip motorized equipment with small hand shovels to throw soil on a fire and keep a cell phone nearby to contact emergency personnel while in the field.
Other precautionary measures to prevent combine fires involve preparing and checking field equipment, according to Mark Hanna from Iowa State Extension Agriculture and Biosystems Engineering.
• Check engine fluid levels (such as coolant and oil) at the beginning of each day.
• Blow leaves, dust and chaff off the engine if compressed air is available. Older combines with front engine compartments can be particularly susceptible to collecting debris.
• Examine exhaust or hot bearing surfaces because they can be ignition sources for dry, combustible material.
• Check the pressurized oil supply line to the turbocharger shaft for areas that may rub from wear and start an oil leak.
• Place wiring harnesses in proper holders.
In addition to the combine, grain transport or pick-up trucks with exhaust systems below the chassis also can ignite field fires. Catalytic converters operate at several hundred degrees.
"Field fires are sometimes started with the passing of a truck. Flames may not be noticed for 15 to 30 minutes or longer. Don't allow extra truck traffic through the field when conditions for fire are favorable," Hanna said.
Because smoldering combustible material may not be noticed for some time, consider leaving the combine out of the machine shed when it first returns from the field. And, if field welding is to be done on equipment, wet down the area under and around the implement before welding as an added precaution.
Reprinted by Grinnell Mutual Reinsurance Company with permission from Iowa State University Extension, October 2011.