Protect against harvest time fires

John Shutske
While fall fires can’t be totally eliminated, a few precautionary steps can greatly reduce the likelihood that fire will ignite inside in your combine or the field you’re harvesting.

Based on crop progress reports from USDA, it looks like corn and soybean harvest is progressing nicely in the state as we begin to see the transition into normal fall weather.

With the limited harvest time window we have, taking the time to protect against combine fires can be challenging. In fact, both prevention and protection are important. The truth is, some machines will burn regardless of what you do to prevent it.

Over the years my former students and I have done investigative work on about 12,000 farm machinery fires including combines, tractors and other specialty harvesters. Based on what we’ve learned, here are important tips for preventing harvest-time equipment fires:

  1. Keep the engine compartment as clean and clear of debris as possible. If you find caked residue or pooled oil often mixed with residue, it probably means there’s a leak someplace. Find it and fix it.
  2. Always listen closely for unusual noises and pay attention to warning lights and sensors that could indicate the impending failure of a bearing, belt or other drive-component. Plan ahead for replacement. Badly worn drive components can generate temperatures hot enough to ignite a fire.
  3. Many combine fires are ignited by the electrical system. If your equipment is blowing fuses, lights are flickering or other electrical problems are occurring, there is likely damage or wear that should be diagnosed and corrected.
  4. The ABC dry-chemical fire extinguisher is the most cost-effective type of fire extinguisher for fires that might involve flammable liquids as well as crop residue. And bigger is better, provided you can handle the extinguisher. Most experts recommend models that are at least 10 pounds. Mount extinguishers where they can be grabbed quickly in the cab AND/OR from the ground. I suggest having two available – it helps in cases of bigger fires or if one of the extinguishers is in the fire zone. In matters of safety, having a backup is always wise.
  5. If a combine catches fire, drive it away from any standing crop immediately and shut off the engine. The longer the fire burns, the more difficult it will be to put it out. If the engine is left running, it’ll be almost impossible to extinguish, even for a fire department. Once a fire has burned for 30 to 60 seconds, it’ll be far more challenging to extinguish it with a handheld extinguisher.
  6. Once the combine is away from the standing crop and turned off, grab your extinguisher, get out and call for help immediately. With extinguisher in hand and ready to use, approach the fire carefully. Begin by aiming for the base of the fire. After you’ve smothered it, continue to blanket the area so there’s time for hot parts to cool down.
  7. Always consider your personal safety. A combine fire that gets into a fuel, oil or other flammable liquid system will burn hot. If the fire ignites a tire, the heat can be incredibly intense. A machine can be rebuilt or replaced. A life cannot.
  8. If you’ve used an extinguisher even for a short burst, it MUST be recharged. If you’re not sure where to recharge and re-tag your extinguisher, call your local fire department.
Two 10-pound or larger ABC fire extinguishers are recommended for combines

John Shutske, professor and extension specialist with the UW-Madison Department of Biological Systems Engineering and UW-Madison Division of Extension, and director of the UW Center for Agricultural Safety and Health. 

John Shutske is a professor of biological systems and engineering and is also an extension specialist at University of Wisconsin-Madison.