The American Locomotive Company 4000-class 4-8-8-4, far more commonly known as Big Boy, is a steam locomotive built for the Union Pacific Railroad in 1941 - 1944. Twenty five locomotives were built and the majority were used on UPs Wyoming Division hauling freight over the Wasatch mountains. The engine is 132 feet long (40.47m) including its tender, weighs 1,250,000 lbs (567,000 kg), with a power output around 6,290 hp. In 1941 the cost to build one Big Boy was $265,000 and in 2015 it has an estimated construction cost of $4,270,577 USD.

Today only eight Big Boys remain, seven now on display at various parks and museums, and one being restored at Union Pacifics yard in Cheyenne. Union Pacific 4014, retired from service in 1959, was donated to the Railway & Locomotive Historical Society in Pomona, CA in 1961 where it remained on display until 2013. In 2012 Union Pacific announced that it had an interest in reacquiring one of its Big Boys and to restore it to an operational condition. On November 14, 2013, UP 4014 was moved from its home at the museum with plans to take it to Union Pacific's rail yard in Cheyenne.

On January 26, 2014, UP 4014 (recently re-numbered on the U.P. active locomotive roster so as to avoid confusion with an EMD SD70M diesel locomotive presently using the number 4014; SD70M renumbered UPP 4014) was pulled out of the Los Angeles County Fairplex by the Southern Pacific liveried diesel locomotive UP 1996 (part of UP's Heritage Series of locomotives). On May 8, 2014, UP 4014 arrived in Cheyenne and on August 12, 2016, the UP steam crew announced work on 4014's restoration had begun.

When 4014's restoration is completed, the engine will join excursion service and will officially be "the world's largest operational steam locomotive. Union Pacific hopes to return the Big Boy 4014 to active excursion service between 2017 to 2019. The restoration includes a plan to convert the locomotive to oil firing. Plans for operating the locomotive include the celebration of the 150th anniversary of the completion of the transcontinental railroad in May 2019.

---

On 4014s journey out of the museum it was moved by Union Pacific SD70M 4884, SD70ACe 1996, ten covered hoppers for braking needs and two SD40Ns 1739 and 1596.

If you're interested in seeing this, or more of my builds, you can visit them on The Realism Society! Just enter the IP mc.realismsociety.com