Locomotive Design

My electronic friends...
There has been a thread here, about steam locomotive design, on which I want to comment.
First, the leaf springs are simply small parts of the complete design. They soften the blows of the track irregularies, but they are not fundamenatal parts of the mechanism.
The great success of the "American Type", the 4-4-0, was its great flexibility. It had a "three point" suspension. The front truck provided the first point. The drivers, supported by equalizing beams on both sides of the locomotive's fire boxes, provided the remaining two points. (When lecuturing, I always use the simile of the the three legged milking stool, which can always sit true on the floor of a milking barn.)
More to follow...
Bob Keller