Feller Buncher Hot Saw and forest fire ignitions

[Montanaforester]

We are searching for any information on Feller Buncher Hot Saw fires, how they started, and what loggers have done to eliminate fire starts.  In Montana, we have been hit hard with fires since the summer of 2000.  Several of these large fires (one was 80,000 acre and multi-million dollar suppression costs) were started by hot saws (contually rotating saw disc) on Feller Bunchers.  The fire fighting agencies want to regulate these during fire season, especially during Hoot Owl.  We have this winter to come up with operating guidelines, supression systems, etc to curb the number of hot saw fire starts before they regulate us out of business during the summer months.

Any information you have, techniques you use, or know of any suppression systems (for the hot saw head) on the machine, would be a great help.

Thanks, Scott

[Tom]

Welcome to the forum, Scott.  Hope you have found a home.

[Gary_C]

I have never heard of fires starting in the hot saw heads, although I personally have never run one. I do know the disc rotates at a very high speed and has so much mass that if you leave it spinning at night, it will spin for over 30 minutes. Or you can cut two trees down after shutting the hydraulic motor that drives the disc off.

I do know that a number of excavators that were converted to feller buncher heads had a tendency to overheat and burn because of inadequate cooling of the hydraulics. But those fires were caused by the machine and not the head.

If I remember right, the John Deere 490 excavator had problems overheating and some of the problems could have been caused by not cleaning the cooling fans and engine compartment.

[Montanaforester]

There were 10 known hot saw related fires in Western Montana last summer. One turned out to be a multi-million dollar, 80,000 acre fire.  Three were while a Feller Buncher (FB) with a hot saw was actually cutting fire line on ta large fire, NE of Missoula.  They caught each at a couple acres, but still sort of ironic.

[Corley5]

What causes the fire ???  Sparks from the head striking rocks ???  I've started a couple grass fires with a bush hog after hitting rocks in very dry fields.

[BCtimber]

I have over ten years on bunchers.  Everything from 618 and 628 timberjacks to newer tigercats and old john deeres here in bc and alberta.  In my experience most of the fires caused by bunchers are from the tracks grinding on rocks in the dry grass.  The huge weight of these machines drive a hot spark deep down into the moss and can take hours to ignite.  I have had one incident when I put the head down on the ground for a coffee break and when I lifted it up again the heat from the bottom of the mandrel turning on the moss ignited.   Mostly though in has been from the tracks.  I suppose an inexperienced operator hitting the rocks with the blade frequently and hard might have a problem but in that case the teeth would be destroyed quite quickly.

[Ron Scott]

We have a number of hot saws working here, but I'm not aware of any fires being started directly by the saw heads. We ocassionally may get a fire start from a bad spark arrester or plugged engine fan, or engine fire. We work on sandy and loamy soils without a lot of rock so don't get a lot of excessive sparking like you may do.

The machines are required to have USFS approved spark arresters, carry fire extiguishers, and a fire shovel. When fire danger gets extreme their operations are shut down until conditions get safer.

[Tillaway]

Associated California Loggers might be able to help you.
http://www.calog.com/

Hot saws are run all summer in California, and do start fires.  One guy was cutting a rather rocky area and was starting fires on an almost daily basis.  I was working around him for a couple of months and was amazed he did not burn the whole place down.  The skidder was working with the buncher.  When the fire would start the skidder operator would have the fire tank out there in a jiffy.  I was amazed the FS allowed him to keep working but they were both on a very tight deadline to complete the sale.

[Montanaforester]

Thanks, I'll check with the CA folks.  I know other states also use humidity as their trigger point to curtail operations.  Montana has a zone (multi-county) broad brush approach.

Most of the fires that hot saws start, flame up after sevral hours and not right away.  So by the time the operator sees or smells smoke, it has had a chance to be big enough to be a problem.  By then they have worked their way up the hill away from the start.