Since these guys are getting tired of trying to explain, I thought I'd keep it up for a while. While I do not pretend to be an expert Shay man, or a machinist of any kind, I have to respect what is being said by the above posters in the theory that misalignement is a long term bad thing. Working around machinists and mechanics of all sorts in the past, I have come to repect the highly experienced machinic's ability to "see" things that are wrong with a piece of machinery, without the rest of the onlookers being able to "see" what is wrong. There are two points in the above arguments that, to me at least, seem to glare out at your argument. One being the point that Lima made different castings and design's around specific parts of the locomotive, specifically because of the allignment and how those parts were affected by the guage. There was a large expense associated with engineering these parts and having them made. It does seem to me, that if all guages of Shay could have been built with either 3' or 4' 8 1/2" wheel sets, with no other changes to the chassis or engine, then Lima would have done so. Granted that a Shay's "U joints" may have taken the abuse - but to one of their other points - maybe not at peak efficiency and long life.
The other point is to the "inside vs. outside curve" argument. It seems to me that how far the "engine" portion or the Shay set in towards the wheel's alignement, would indeed have an effect on the designe and function of the drive line. If you imagine the drive line as a curve, when the Shay entered a curve, the curve would have to be "stretched" ( or vice versa "squeezed") more, IE. the length of the shaft, than if the "engine" portion of the drive line were more in line.
I would love to here a more technical, engineering point on all of this, as I am SURE, that somewhere out there, someone is mathamatically smart enough to give all of our supositions a definitive answer, but with all do respect for your opinon on this matter, it seems that your only true "evidence" are photographs. While they do give rise to your theory that as long as they are out of allignement in one plane, they can just as easily be out of alignement in two planes, they do not prove your point. I would love to see more scientific, mathimatical, enigineering, proof on this subject from both parties, as I find it intriguing. But for now, I set squarly on the side of the guys who have wrench's, calipers, and years of experince maintaining these monsters, than in a bunch of one diminsional photos on a book shelf. Yours truly - and I hope still a friend.
Rodger Polley
