>>1283167Nah, it is just a mix of bad coal, too much coal and running the engine at with the valve timing all the way up for extended periods of time.
This is terribly inefficient and requires insane amounts of steam, wich also means a shitload of steam comes out of the chimney pulling combustion products out of the smoke-box, wich means particles of unburned coal can pass through the boilers tubes.
With steam engines it usualy more or less like that:
>boilerlimits maximum power
>enginelimits maximum torque
Extreme cases like the 4000 series BigBoy have insane levels of torque rivaling many modern diesel locos, but can't go fast.
And the PRR T-1 wich builds builds pressure at speeds in excess of 100 mph and is notorious for wheelspinn.
