We were not fighters like them; we were cunning and cowardly, and it was because of our cunning and cowardice, and our inordinate capacity for fear, that we survived in that frightfully hostile environment of the Younger World.
Union Pacific's 4-6-6-4 Challenger steam locomotive #3985 is the largest operating locomotive in the world. Built in July 1943 and still used by UP for occasional excursion throughout the western United States, the 3985 weighs 1,073,900 pounds (537 tons).
So what was the most powerful steam locomotive ever built...if you go by horsepower ratings? From what I've found out so far Pennsy's Q2 had the most horsepower of any steam locomotive (I've listed the locomotives that I know the horsepower ratings to). Also what where the horsepower ratings on some of the other big locos that I didn't metion below. PRR Q2=8000hp. UP Big Boy=6300hp.