Key - UP #4020 - Locomotive, Steam, 4-8-8-4 Big Boy - Union Pacific - 4020

Prototype History: Big Boy is the popular name of the American Locomotive Company 4000-class 4-8-8-4 articulated, coal-fired, steam locomotives manufactured between 1941 and 1944 and operated by the Union Pacific Railroad until 1959.

The Big Boy fleet of twenty five locomotives were used primarily in the Wyoming Division to haul freight over the Wasatch mountains between Green River, Wyoming and Ogden, Utah. They were the only locomotives to use a 4-8-8-4 wheel arrangement consisting of a four-wheel leading truck for stability entering curves, two sets of eight driving wheels and a four-wheel trailing truck to support the large firebox.

According to Union Pacific senior manager of Heritage Operations Ed Dickens Jr., the 4-8-8-4 series originally was to have been called "Wasatch". One day while one of the engines was being built an unknown worker scrawled "Big Boy" in chalk on its front. With that, the legendary name was born and has stuck ever since.

Read more on Wikipedia and on SteamLocomotive.com.

Road Name History: The Union Pacific Railroad (reporting mark UP) is a freight hauling railroad that operates 8,500 locomotives over 32,100 route-miles in 23 states west of Chicago, Illinois and New Orleans, Louisiana. The Union Pacific Railroad network is the largest in the United States and employs 42,600 people. It is also one of the world's largest transportation companies.

Union Pacific Railroad is the principal operating company of Union Pacific Corporation (NYSE: UNP); both are headquartered in Omaha, Nebraska. Over the years Union Pacific Corporation has grown by acquiring other railroads, notably the Missouri Pacific, Chicago & North Western, Western Pacific, Missouri-Kansas-Texas, and the Southern Pacific (including the Denver & Rio Grande Western).

Union Pacific Corporation's main competitor is the BNSF Railway, the nation's second largest freight railroad, which also primarily services the Continental U.S. west of the Mississippi River. Together, the two railroads have a duopoly on all transcontinental freight rail lines in the U.S.

Read more on Wikipedia and on Union Pacific official website.

Brand/Importer Information: Key Model Imports is an importer of brass locomotives.

Manufacturer Information: Samhongsa was a Korean manufacturer of model trains, well know for its brass models, imported notably by Hallmark Models. The company ceased its activity in the early 2000s. Some of the employees continued the brass model business as Sam Model Tech.