[Steam-engine] Safety valves...now firing

[Best, Dianne]

I will not dispute any "common knowledge" about dampering a coal fire
being hard on grates but simply say I have been running my 1/2 scale
Russell on Pennsylvania "Blacksmiths coal" for 7 years. When working, it
provides the whitest, hottest fire I have seen. The baby Russell is very
air tight and if I close the damper, it will put the fire out in a very
few minutes. It seems that being suffocated stops the combustion process
VERY quickly - the white and yellow coals turn black within a minute or
two and I think the only heat left is the heat in the unburned coal.
There is no increase in pressure, which tells me there is little heat
being transferred and the combustion process has stopped.

I am still on the original (cast iron) grates and they show no sign of
abuse or deterioration (except rust). Haven't found a good "grate paint"
yet for a coal-fired engine ;-)

Dianne