A couple of folks have PM'd me to ask about "what's an F7?" and What do the numbers mean when you say 4-8-2 etc.
4 leading wheels 2 each side (small ones right behind the so-called cow-catcher). These actually steer the locomotive around corners
8 Drive wheels
2 more small ones under the cab
The truly humongous ones were the Union Pacific Big Boys which were 4-8-8 4 and the Challengers which were 4-6-6-4 with two sets of pistons/drivers per side.
For a pic of an F7, check out this Wikipedia: Wikipedia, the free encyclopedia
and for a pic of the Mountain Class that pulled passenger trains when I was a little munchkin : CN U-1-f - Wikipedia, the free encyclopedia
And for those who wondered about my Dad's trailer
When I was growing up, the town had no services such as welders, etc, so my dad went to the nearby town of Roseau, Minnesota to have a trailer built. The guy who did it was experimenting with self-propelled toboggans like the ones he had heard that Armand Bombardier was making in Quebec. He later went into production of them, under the name Polaris
. Polaris Snowmobiles, Polaris ATVs and Victory Motorcycles are the result - all "descendents of" my dad's utility trailer which I now own.