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TJHELMS
10-18-1999, 03:52 PM
I need some help with a coal fire investigation. The building houses a coal crusher on the first floor which feeds a 36" rubber conveyor in the basement. The crusher was down with the motor removed for repairs. Grinding was being done on the steel motor mounts ending at 10:00 am and men were on fire watch until 11:00 am.There are numerous openings in the floor between levels. At 11:05 pm two sprinklers activated above the conveyor extinguishing the fire which had consumed 8ft. of both upper and lower conveyor belts. The fire was also directly below the area where the grinding took place 13hrs earlier.
I have not had much exposure to fires dealing with coal and coal dust.
My question is ... Would the coal dust be able to hold a hot ember from metal grinding and sustain the temps needed to ignite 12 hours later?
Dust was about 1" thick below conveyor.
Men working also claimed to wetting the basement floor with water prior to grinding.
All other sources of ignition have been eliminated.
Any help would be greatly appreciated.

mtnfireguy
10-18-1999, 06:00 PM
Contact the Campbell County Fire Department in Gillette Wyoming 307-682-5319 and ask for one of the fire investigators.

They also have email at ccfire@vcn.com

They deal with coal fires on a regular basis and should be able to help you

TJHELMS
10-22-1999, 10:36 AM
After another round of questioning and a through overhaul,it was found that a 1" bolt that had been torched off at 9:00am had possibly fallen into the bin that feeds the conveyor.The bolt was found in a pit under the conveyor directly below the bin and conveyor.It looks like that could be the ignition source.We are in the process of doing our own experiments with coal dust and hot bolts to see if we can duplicate the time frame.
Thanks for the help guys.

Lt. T.J.Helms
Freedom Fire Company
Kaukauna,WI