Union Pacific Big Boy No. 4014 Currently the largest operating steam locomotive in the world! 📹 credit: @accuscale_models (check out on Instagram for some more Big Boy clips!) Originally engineered to haul freight over the Wasatch Range from Ogden, Utah, to Green River, Wyoming, the Big Boy locomotives are known for their powerful 4-8-8-4 wheel configuration. This design was specifically chosen to handle the difficult mountainous routes efficiently. By the late 1940s, their route shifted to run