Powdering is key: it dramatically increases the area-to-volume ratio [combustion in a gas atmosphere happens on the surface] and minimizes the production of incompletely combusted products, which are generally dangerously polluting as they are chemically active (example: carbon monoxide is the result of incomplete combustion and is a poison as it binds to hemoglobin more strongly than osygen; carbon dioxide is the result of complete combustion ans is chemically inert).

guaranteed to evoke a violent reaction from police is to challenge their right to "define the situation." --- David Graeber citing Marc Cooper

The one surviving (East) German coal powder locomotive (recognisable due to high tender), [class] 52 [no.]  9900:

...as you have given me another opportunity to push trains...

_{*Lunatic*, n.
One whose delusions are out of fashion.}