Fairbanks-Morse Opposed Piston Engine

[curtissjoyce]

The cross section drawings of the engine I have seen show a crankshaft on the top and one on the bottom with two pistons in each cylinder in opposition to each other. If both crankshafts were turning independently of each other, how were they used? Were there separate generators connected to each for the traction motors that essentially operated indepently of each other, or what? How was the power utilized?

[arbfbe]

The two crankshafts were connected on one end by gears.

[M636C]

To expand on arfbe's comment, at the "free end" of the FM engine, the end away from the generator, there was a vertical shaft with bevel gears on each end connecting the two crankshafts. Ithink there was some flexibility built in using springs, like automobile clutch springs, to absorb any shocks in the gearing.

As I recall, the generator was driven by the lower crankshaft and the roots blower (a supercharger) was driven by the top crakshaft. The timing was set up so that about 60% of the power went through the bottom shaft, and 40% through the top. At lower speeds when the blower didn't need that much power, the connecting shaft transferred it to the bottom shaft to drive the generator.

The English company Napier built an engine like this with three crankshafts arranged in a triangle, six cylinders long, that therefore had 18 cylinders and 36 pistons. There were locomotives built with two of these engines, driving separate generators. The engines and the locomotives were called "Deltic" after the Greek letter "D" (or delta) which looked like a triangle. These engines had direct spur gears connecting the crankshafts and a single output shaft driving the generator.

One of the Italian engine builders went one better and built an engine with four crankshafts arranged in a square, but it had the crankshafts vertical with a right angle drive to the generator. This never was used in a locomotive or anything else that I know of, but at least one was built and tested.

Peter

[curtissjoyce]

THANKS FOR THE INFORMATION!!

[Modelcar]

....Peter, that's wild...! Makes a radial airplane engine sound like a mere tinker toy....!

[CSSHEGEWISCH]

Peter:
I'm aware of the Deltic design and its use on British Rail. How successful was the design in everyday use and how did its maintenance expenses compare to more ordinary designs.
Paul