Big Boy 4014 Live Tracker Today: Best Vantage Points, Webcams, and Photo Spots
By Sarah Jenkins
No. 4014 is an astonishing mechanical survivor. Built by the American Locomotive Company (ALCO) in 1941, it was designed specifically to haul heavy wartime freight over the steep Wasatch Mountains without helper engines. Union Pacific's steam shop crew in Cheyenne, Wyoming, completed an exhaustive multi-year heritage fleet restoration, converting the machine from coal to No. 5 heavy fuel oil. That conversion eliminated trackside cinders while dramatically simplifying logistics on the road.
The locomotive uses an articulated chassis that splits its 68-inch drive wheels into two independent engine sets: a four-wheel leading truck, two groups of eight drivers, and a four-wheel trailing truck. This hinge-like design allows the massive rigid frame to negotiate mainline curves that would otherwise derail a locomotive of this length. When the throttle opens, 300 psi of saturated boiler pressure converts into more than 7,000 horsepower, vibrating the ballast beneath your boots.
Behind the historic tender runs a modern diesel support locomotive, typically a UP heritage SD70ACe or clean Tier 4 unit, coupled to water auxiliary cars and the support crew's mobile workshop. The diesel unit is not pulling the train. Instead, it supplies dynamic braking assistance along downhills, powers positive train control (PTC) electronics, and provides house electricity for the support coaches, preserving the steam engine's brake shoes and mechanical parts during coast-to-coast tours.
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
