Mounted corn pickers used to burn often--I believe they were the first things that got fire ext mounted on them---the exhaust systems had a screen system put on to help keep the corn shucks away and invaribly if they didn't keep them clean, thats where the fires would start from very fine debries thatt built up

By the way----I'm so old that I drove the mules too

First mechanics job was making gasket out of a Nabisco shredded-wheat box with a small ballpein hammer(about 5 years old)