There was only one 5000 Class (Locobase 457) ATSF steam locomotive, road number 5000, known as Madame Queen.

ATSF 5006 was actually a Texas Class 5001 (Locobase 458) locomotive, and the first oil burner in the series of 10 (road numbers 5001-5010). Some sources say this class developed the highest piston thrust ever recorded, 219,000 lb.

[Back when they were new, these engines were referred to as both 5000-class and 5001-class, if numerous newspaper accounts are any guide. The article below details the wreck of ATSF 5004, a "giant 5000 class locomotive." - Dave]

I've seen plenty of steam locomotive pictures over the years, and appreciate pretty much all of them. But every once in a while there's a photo that really sums up the power and poetry of steam engineering. A massive machine designed with a single purpose in mind, where every individual component has a utilitarian form and reason, and whatever "styling" the whole has is dictated purely by function and a century of experience and refinement. It's a beautiful beast.

Also, props to the Shorpy logo for paying tribute to the wheel arrangement!