I would like to show you pictures of a 22-foot steamboat that I built when a teenager. It was made of 22-gauge galvanized iron and my younger brother held a weight on the head of all the rivets after he had inserted them as I drilled the holes for them. We steamed and bent two 1 by 6 oak boards to form the round ends of the coaming the purpose of which was to increase the clearance above the waterline.
Our father let us use his Toledo steam engine and a small porcupine boiler, which boiler was all made of black iron pipe. The engine crankshaft was directly connected to the propeller shaft and was installed under the removable wooden cover which can be seen at the bow of the boat. The boiler was at the stern, as shown, which made for plenty of passenger space amidship.
I used a wood fire for starting and a mixture of anthracite (hard coal) and coke for the main fuel supply. We don't know what speed it would make, however, a local man had a factory-made boat with a Fairbanks & Morse 9 HP marine engine, and if he had some passengers sitting on the stern-end seats of his boat then we could go faster then he did, but not if he was alone and sitting on the front seat.
I believe that anthracite coal is a low sulphur fuel and I wonder if you or someone can tell me about how plentiful it still is? I understand that pulverized or powdered coal can be handled much the same way that liquids are handled. In which case, if we run out of gasoline for our road vehicles, I am certain that motor vehicles can be fueled with coal in the above manner without too much inconvenience, in spite of what misinformation may be forthcoming from the modern day so-called experts.
The above mentioned water-tube porcupine boilers will have steam ready to use just about as quickly as the oil or coal fire can be made ready and they are safe because there are no pressure vessels to explode. Mud or lime in the feedwater is no problem because it always settles in the mud drum so that occasional quick opening and closing of the blow-off valve is all that is required. After WWI, this same boat was repowered with a 3-by-4 Stanley steamer engine and a similar, but larger, porcupine boiler, using a Stanley kerosene burner and controls, including a feedwater automatic regulator, all of which gave fully automatic steam power which was ready as soon as the burner had been started. I sure wish that I had a new boat just like that one was.