Re: Fuel type and firebox wear/damage

Each has it's advantages and disadvantages.

A coal fire's changes in temperature are is much more gradual and the burning bed of coal gives a more consistent temperature all throughout the firebox. The disadvantage is the cinders cut into the firebox sheets, staybolt ends and rivet ends.

Oil has the difficulty of rapid changes in firebox temperatures, and more variation in firebox temps (the firebrick helps this). The greater expansion and contraction in an oil burning firebox creates more firebox repairs.

Wood would seem to be ideal fuel in that it does not cinder cut the firebox and has a burning bed of fuel (although much less than coal) to keep the firebox temps evened out. But, you consume a much greater amount of fuel because the BTU/lb. is much less than coal or oil.

When determining the "best" you have to combine all the elements of cost maintenance, supply, storage, etc.

Without a doubt, burning oil is the toughest on a firebox. However with oil, you store it a tank, and pump it into the tender. Coal needs a pile somewhere, someway to load it, you need an ashpit and a way to empty that. You also have a greater concern with cinder fires. Coal in general is much dirtier. Add all that up and costs even out. At present, coal is much cheaper to get than residual oil. The bagasse was essentially free fuel, which was good because there is very little heat in what is essentially straw.