I had this model built to my design ( actually Tesla’s design ) in Canada in 1980 when I worked up there. The mild steel cube is about 2.5 inches on an edge. The shaft and disks are of one piece of bronze. There are only three main parts, 4 screws and two locating pins for the end cap. It turns with compressed air at about 10,000 RPM. I’ve forgotten the running pressure I used, but it will run at 20 to 100 PSIG without any trouble I believe.

No vibration to speak of, but you know it is turning! Very simple to make. Essentially self-lubricating when these materials are used. Steam could also be used. Or hot gases, but watch out for melting! If I were doing it over, I would make it larger in diameter to realize some power. Not the most efficient thing on earth, but when you consider how easy it is to make and maintain, that’s got to be worth something from the “overall efficiency” standpoint! Tesla describes this in a very short paragraph in one of the biographies of him. I “built” it from that verbal description alone. The first time I hitched it up to an air hose it did not run. Then I reasoned that I had made the exhaust holes between each disk too small. So I opened them up to about the same diameter as the space between each disk. It took off like a bandit.

A dramatic difference right away. The only modification to it I ever made. It’s a neat project. This turbine could be made bigger and then run with steam from a boiler. The design for a simple boat motor would be to let it turn an automobile alternator and generate electricity. These alternators turn around 8,000 RPM anyways. So you don’t need a gear box. Then send the rectified current to a few batteries and then a car starter motor to the propeller shaft. Presto…a steam turbine boat!

I think American car alternators can put out around 40 amps at about 13 volts. That’s about 520 watts. (746 watts makes a horsepower. ) If the alternator and electric motor add up to about 50% efficiency, then you’d have about 1/3 horsepower available. That’s enough power to drive a 14 foot boat at about 6 knots. Plenty fast for this lad.