March 7th Steam's up!

[Lamplighter]

Originally Posted by xoxoxoBruce

G'wan, you ain't foolin' me, that's gotta be a photograph.

Very simple, want to pull monster loads over big hills, you just build a bigger, badder, locomotive with more grunt. But even with 16 drive wheels, and gigatons of weight on them, the total contact between the wheels and the track is miniscule...infinitesimal. How in hell do they transfer all that grunt?

Weight ... the more weight the higher the coefficient of friction on the rails.
Then all you need is the torque to get it started and keep it rolling,
... and occasionally, to stop it when that is needed.

[xoxoxoBruce]

Yes it does, but the contact area to apply that to remains the same. At some point the wheels and/or rail will gall and deteriorate. I did notice the Big Boy has maximum traction at 10mph.