Posted by chriscase on Saturday, March 17, 2007 at 18:59:44 :
In Reply to: An email just came in with a Very Good Question. posted by Clint Dixon on Saturday, March 17, 2007 at 10:00:30 :
Think of a wine barrel shape, with out the middle section. As the car moves to the outside of the tack, the inner wheel is smaller diameter where it hits the track. While the outer wheel is a larger diameter where it touchs it's track. So the 'barrel' turns toward the inside of the curve.
I'd say it's such a simple system that it never occurs to people how sophisticated it really is. A solid axle. One moving part. But it is a functioning differential. James Watt, maybe? Stevenson? whoever, a true genious.
Occasionally you'll see some educational TV show where they are rolling liquor barrels down 2 wooden 4x4's. You see the barrel wobble a bit, side to side, but generally go down the tracks. I'm sure that was the RR designer's inspiration.