UP's steam engine drivers

Trains Magazine Steam & Preservation
21

Thanks, Mark. I feel I understand your second description well. I would guess that those studs are to inhibit the tire from creeping/slipping under load or hard braking? Or is it for lateral retention…maybe all of the above?

The Gibson rings sound like I’ll need an image or diagramme…I keep conjuring up images of a large gravel truck’s split-rim type of design, but that wouldn’t be right on a driver.

I’ll wait.

-Crandell

22

This is a page from the book “Train Wrecks”.

Clearly shows the tire and the wheel.

23

In Pentrex’s video “Steam across America” at the very end, they sow some work on one of the wheels of a Big Boy in the Cheyenne roundhouse.