Boy - Fe Big

: The frame is "hinged" to navigate tight curves.

: The 14-wheel tender carries roughly 25,000 gallons of water and 28–32 tons of coal. Where to See a Big Boy Today Union Pacific Big Boy: History & Facts - Ftp FE Big boy

The (4000-class) is the largest and heaviest reciprocating steam locomotive ever built, designed specifically to haul massive freight trains over the steep Wasatch Mountains in Utah and Wyoming. Key Features and Specifications : The frame is "hinged" to navigate tight curves

: Features 4 leading, 16 driving, and 4 trailing wheels for immense traction. FE Big boy

The Big Boy is a marvel of 1940s engineering, built to a scale that remains unmatched by other steam locomotives.