Steam Engine Terminology

Trains Magazine Locomotives
1

Could you explain the meaning of a “one spot” steam engine, or a “two spot” steam engine. I’ve found references from -, 2, 4, 5, all the way up to eleven. I’ve been all over Google and other sites and it seems it is old terminology from the earlier steam engines including Shay locomotives. I’ve tried to relate it to the number of times the crankshaft turns to a revolution of the drive wheels and other things such as the number of cylinders. None link up to the jargon, however; when entering "one step steam engine on Google, several samples of engines on display label them as a one spot or two spot without explaining what that means.

Thank You

Michael Schafer

lineswest@hotmail.com

2

Normally a reference to a number plus the word “spot” as you have used it refers to the locomotive’s number. Usage like this is normally reserved for Short Line railroads with rosters of very few locomotives.

3

I remember this question being raised by DPM many years ago in “Second Section”. Several answers turned up in “Railway Post Office” and they all centered around playing cards. Playing cards from Ace to Ten have the appropriate number of pips, or spots on them. Consequently, engines or cars numbered from 1 to 10 became One-Spot, Two-Spot, etc.