bpetit wrote:Does it produce more or less the same Drawbar HorsePower as coal?
That's not at all related to type of fuel, that has everything to do with the power of the locomotive, steam pressure, cylinder size, driver size, and so on. Fuel plays no part in those calculations.
The biggest difference between Liquid fuel (oil) and solid (coal and wood) is planning. With oil, your planning lead time is maybe a minute. When you add more oil with the valve it takes under a minute for you to notice a difference in pressure. With Coal, its closer to 15 minutes, and wood, your planning 30 minutes before you need steam.
As a result, Coal and Wood are far more of an art form then oil is, oil is far easier to teach, and far easier to learn. If you can't figure out oil, you have a bigger problem.
I've fired both coal and oil. My first trip with oil was on the Loop, and I did just fine. My first trip with coal was with 346 at the Colorado railroad Museum (not as demanding as the Loop by any stretch) and I did terrible, although my second trip I got into a bit more of a groove, but I still had a messy firebox at the end. A huge pile in the back, and a huge pile about 2/3 of the way down the firebox. Nothing up front, and pretty much perfect between the backhead and the pile beyond the middle.