Big Boy #4014 Steam Show

Big Boy #4014 floating on a cloud of steam !!

UP took the old 4-6-6-4 Challenger design and enlarged the fire box, lengthening the boiler, adding 4 driving wheels, and reducing the diameter of driving wheels from 69 to 68 inches. These changes contributed to Big Boy’s overall length equal to two city buses and the combined weight total of more than a Boeing 747!

Big Boy is an articulated locomotive with compounding of the steam meaning steam is used once on both sets of driving wheels front and back. An articulated locomotive has the front of the boiler sitting on a front wheeled truck that allows the otherwise ridged boiler to pivot around curves that would normally be too tight.

Big Boy was also designed to operate safely at a maximum speed of 80 mph which was unheard of for steam freight locomotives in that time.

Let us know if you have ever seen Big Boy #4014 in action. We would love to hear about your experience!