Mr. Water is correct; the 9000's were 3-cylinder Simples.
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I have the Lionel version (TMCC); bought lightly used. Smoke does not work (this was made
when Lionel pretended to have smoke units) and the 3rd cylinder gear on the pilot
is not a functional design on the Lionel model. Wish that it were.
But, runs and sounds nice. The 9000's were such an impressive design, actually considered high-speed freight locos, and were so good that even after the 4-6-6-4's knocked them
down the totem pole a bit, they did not replace them and they lasted pretty much until
the end of UP steam, I believe.
I'm not a UP fan, but these things (and the gas turbines) have always attracted me.