This Challenger is the largest locomotive currently working. Being in the USA, it has to be the BIGGEST, although there is a Big Boy under rebuild at the moment. That is an even larger beast.
What is fascinating is the speed these magnificent locos can achieve. Here in Australia, we have restrictions on steam train speeds these days. No longer can some trains travel 90 MPH or more.
The video below is very impressive as you watch one of these engines motor along.
The UP 3985 was one of the Challenger series steam locomotives and built tough. A steam locomotive that was first built around the beginning of World War II in order to haul freight and passengers without helper engines, especially on steep 1.14% grades. Imagine our troops packed into her passenger cars being transported to their training destinations! Currently she is in the roundhouse in Cheyenne, Wyoming. Her last regular train service was in the late 1950’s.