The Atchison, Topeka and Santa Fe Railway class 5011 was the last class of steam locomotives to be purchased by AT&SF. The class was introduced by Baldwin Locomotive Works in 1944.
A total of 25 of these large engines were built. They were nicknamed "War Babies" by the AT&SF from being built and used during World War II.
The AT&SF ran the class from the mid-1940s to the mid-late 1950s. Despite being mainly freight haulers, their driving wheels were unusually tall for a "Texas" type, which led to them also being successful in passenger service.
Numbers 5011 to 5035, when built, were the largest and fastest class of "Texas"-type locomotives ever built and equipped with Timken roller bearings on every axle.
The engines had a maximum output of measured at the rear of the tender, at a top speed of .
Four of the class 5011 locomotives were preserved by the AT&SF for museums, with the remainder being scrapped.
The four preserved locomotives are: