It seems to me that most, if not all, steam engines have drive wheels in even numbered sets of wheels: 2-6-2, 4-8-8-4, 2-6-0, etc. I don't recall ever seeing a 2-5-2 or a 2-3-3-2. I think I understand the weight distribution issue requiring the sets to be equal( you wouldn't see 1-3-5-2), but am not clear on the reasoning, the mechanical or physics principles driving (sorry) the even numbered sets. Or am I wrong. Are there odd numbered and different size sets? There may be some obvious answer that a non-engineering type like me doesn't get. Anyone know?
Posted by MPALMER (Member # 125) on :
Ira,
Steam engines are numbered by total wheels, not wheel sets. A 2-6-2 means there is one lead truck with 2 wheels, 6 driving wheels, and 2 trailing wheels.
Mike
Posted by Ira Slotkin (Member # 81) on :
Ahhhh, got it Mike. Thanks. Nothing like having someone point out the obvious to make me slap myself up-side-the-head. So much for my basic math skills.
Ira
Posted by pjb (Member # 2671) on :
In places (like continental Europe) where Whyte system is not used, axles are counted. Hence your Prairie type becomes a 1-3-1 in France, for example. Good-Luck, PJB