March 7th Steam's up!

[Carruthers]

A few days ago I bought a second hand copy of the book 'Terence Cuneo, Railway Painter of the Century'. It includes a large number of his best paintings.

I was especially impressed by this work.

The Mightiest of the Mighty

A Union Pacific ‘Big Boy’ takes on coal and water at Harriman, Wyoming, before tackling the heavy grades of Sherman Hill.

Introduced in 1941, these 4-8-8-4, 594 ton locomotives were the largest ever built and were the equivalent of four conventional engines.

New track had to be laid to cope with their great weight and new turntables for their length.

In all, 201 were built of which six remain today. (1990)

Union Pacific Big Boy

Wiki suggests that 25 of the locos were built and not the 201 quoted in the book.

Terence Cuneo

[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?

[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.