J.B.Bane Wrote:
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> As to wood, I don't think we have ever had a
> broken staybolt on the WHEccles #3 Heisler, nor
> has it had any firebox work done on it. Likely it
> is original. It apparently did have coal burned
> into it during it's few years of operation in
> logging service in Idaho. Flues have gotten to
> weeping from time on the firebox end which is
> pretty easily remedied I think. Since this old
> girl has really gotten a work out year after year,
> I think this is a testament to wood being a more
> gentle fuel than coal or oil as far a boiler
> maint.
19th century sources written when wood was still in common use as fuel regarded wood as much less destructive to fireboxes relative to coal, due to the lower temperatures produced. This applied to fireboxes made not only from steel, but also copper and even iron--the latter material being regarded as particularly inadequate when coal fuel was used. Late 1860's and 1870's era sources regarded copper fireboxes as uneconomic for coal-fueled locomotives because the copper sheets had to be made so thick as to eliminate any advantage gained from that material's greater thermal conductivity compared to cheaper steel. In addition, particles from wood fires were also generally regarded as very much less damaging to boiler tubes compared to coal cinders. Wood's downside is that it's an inferior fuel to coal in just about every other respect, from consistency of performance to energy density to ease of transport and handling. I haven't seen many firemen say many nice things about the workload involved in firing wood-burners, although I've known a couple who admitted it wasn't as filthy as coal.
The railways of Brazil, especially metre gauge railroads, often used wood fuel well into the 20th century owing to its availability. This included some fairly modern locomotive types including superheated Mikados and Pacifics and mallets.
