Don Bourdon up in Woodstock, Vermont, not the place in New York where the pig farm was, is the main manufacturer of Stanley boilers in the world. There are three sizes; 10 hp, 20 hp, and 30 hp. Most people get confused by these horsepower ratings and think that the Stanley engines put out these power ratings. For an example a 20 hp Stanley engine will put out somewhere in the 65-100 hp before something bends or it runs out of steam. The horsepower rating is what the burner can do at a steady state and has nothing to do with what the boiler and engine can do on stored energy with the several gallons of hot pressurized water in the boiler.
The boilers are quite cleverly designed and they never blow up. They are a vertical water tube thing with copper tubes, steel ferrules, and a steel drum wound with 3 or 4 layers of 300,000 psi piano wire. The wire is wound with some weight on it mildly stretching the wire. The boiler shell expands with steam pressure to 350 psi and at that point the wire takes over and the shell does not expand any more. The vertical fire tubes are the stay bolts of the boiler. They keep the bottom sheet and the top sheet from spreading apart. Rigid and unrealistic boiler laws in Great Britain do not allow wire wrapping and thus the boiler shell has to be several times thicker than the original Stanley and thus it weighs much more over there.
The safety in this system is in the copper tubes. They will collapse inward one at a time when the pressure gets too high and long before the shell and wire breaks. Some people have used cupro-nickel tubes and they work and one can swage them without using steel ferrules, but the safety factor is missing with this material.
What happens mostly in this type of a boiler is that it scorches. That happens when the water runs out and is all evaporated and the bottom sheet glows red hot from the fire. When there is water in the boiler the hottest the steel bottom sheet gets is 50 degrees hotter than the water temperature inside. When the boiler scorches everything expands and does many things and mostly leaks. The solution is to not run out of water. Carefully watching the water sight glass helps and remembering to close the water pump by-pass valve helps also, and general awareness helps. The other solution happens after the boiler scorches and it is to swage the ferrules. This involves a three pound maul and a tapered swaging tool and lying on your back underneath the car for a day pounding uphill. People who have done this say that a lot of thought happens while in the process.
We are not certain of the historical antecedents of this boiler design. The rumor is that it was originally used to can green beans. It is a fairly efficient way, although expensive, to boil water. The current problem with them is that in a condensing car the oil in the water will carbon up the bottom sheet and insulate it causing it to over-heat and do many bad things. The oil is for lubrication. The other problem is that when over-fired the water lifts and thus the bottom sheet will overheat.
The other thing in the photos is a burner. This is a vaporizing burner that can be used to burn gasoline, kerosene, or diesel fuel. The firing up procedure appears at first blush to be complex and difficult. People who know what they are doing make it look easy and simple. To appreciate this burner what you need to know is that when it was invented and designed in 1895 they had not invented electricity for cars. There were no generators or regulators or small electric motors to power air fans and fuel pumps, or any spark ignitors. All they had were batteries. The genius of this burner is that it runs and turns on and off and does all that is asked of it by using expanding pieces of metal; expanding from the heat of the water or steam. It also turns on and off with steam pressure, making for a completely automatic vehicle when everything is working properly. There is a way to sense water level in the boiler and that puts water into the boiler when needed. These things are called fuel automatics and water automatics, another topic for another time, but all very clever.
What is involved in starting up is a pilot light is lit to heat up the fuel to boiling and then two nozzles that shoot the high pressure fuel vapor into two tubes drawing in air and making enough pressure to push all of this flame through the boiler. Once things are heated up then the pilot light does not have much to do except make certain that the main fuel fires when it comes back on. The cast iron plate that is the grate has either thousands of little holes drilled in it or hundreds of little narrow slits sawed into it.
This is called a blue flame burner. It is a very compact, clean burning, way to make a flame. The beauty of the vaporizing burner is that the power made by boiling the fuel is used to pump air into the combustion chamber and up through the small holes that keep the hot part from the cool part so the fire burns where it is supposed to; above the cast iron grate. Sometimes the fuel carbons up as it is being boiled and blocks the vaporizing tube and sometimes bits of carbon block the small jets where the vapor shoots out. There are many opportunities for things to go wrong, all the way from the wind blowing out the pilot light on up, however, this is nearly the only way fuel could be burned and water boiled with the technology of the time.
Don Bourdon is keeping many Stanleys going and running reliably and safely.