Railroad history enthusiasts will be able to catch a glimpse of a historic steam engine this week.

Union Pacific Railroad’s restored Big Boy steam locomotive is scheduled to run through Arkansas, from Texarkana to Prescott on Wednesday and then from Prescott to North Little Rock on Thursday. On Friday, the historic locomotive will travel from North Little Rock to Poplar Bluff, Mo.

This won’t be the historic engine’s first visit to Arkansas.

Because as the Golden Spike ceremony at Promontory Summit, Utah on May 10, 1869, involved Union Pacific, the railroad thought it fitting to restore a Big Boy for the 150th Anniversary celebration in Ogden in 2019.

After an exhaustive study of the remaining Big Boys, Engine 4014 was reacquired and moved from Pomona, Calif., to Cheyenne, Wyo., for rebuilding.

After operating to Ogden, Big Boy 4014 embarked on two UP system excursion tours in 2019. The first tour, from July 8 to Aug. 8, was through the Midwest, and the second, from Sept. 27 to Nov, 26, was a large circle through the Southwest. The route included running from North Little Rock to Van Buren and on to Kansas City.

In 2019, Big Boy also stopped for a half hour in Russellville.

Big Boy History

Severe drought throughout the center of the United States, along with the Great Depression, caused nearly a half million Americans to migrate west in search of jobs. Many settled in southern California, the San Francisco Bay Area while others went to the Pacific Northwest.

As economic conditions improved, increasing volumes of farm produce flowed from California, Washington and Oregon to eastern markets. At the same time, the demand for manufactured products and raw materials in these three states also grew.

The Union Pacific Railroad was well positioned to handle these ever growing freight volumes; however, the stiff grades over the Wasatch Range, between Ogden, Utah, and Green River, Wyoming, was an obstacle. UP’s Challengers, their largest locomotives at that time, could not handle trains exceeding 3,600 tons, in either direction, on this 176-mile long segment. By 1938, nearly every train east from Ogden or west from Green River needed a helper, a second engine up front or on the rear, which added cost and delayed trains.

In early 1939, Union Pacific design engineers worked with American Locomotive Company engineers in Schenectady, N.Y., to come up with the “perfect” engine.

They determined that adding two more driving axles to the proven Challenger design, increasing the size of the fire box and increasing boiler pressure to 300 psi and reducing driver diameters by one inch (to 68 inches), the new locomotives would do the job. They were the world’s largest steam locomotives, and their 4-8-8-4 wheel arrangement was never duplicated.

UP wanted to name the new class “Wasatch” but while 4000 was being assembled, an unknown workman wrote “Big Boy” in chalk on the smoke box door. The name stuck.

Challengers and Big Boys were articulated locomotives, meaning there are two engines (separate frames) under one large boiler. The frames are hinged behind the fourth pair of drivers of the front frame and just ahead of the cylinders for the second set of drivers. The four-wheel pilot truck supports the front of the boiler and guides the massive locomotive around curves and through switches.

The boiler, plus smoke box and fire box, are rigidly secured to the rear engine frame, with its four drivers. The four-wheel trailing truck supports the huge fire box that was needed to efficiently burn the low-quality bituminous coal from UP owned mines in Wyoming.

The seven-axle “centipede” tender carried 28 tons of coal and 24,000 gallons of water. When 4014 returned to service, No. 5 fuel oil replaced coal and two additional tenders boost its water total capacity to about 75,000 gallons. Dynamometer testing in 1941 calculated maximum power output as 6,200 drawbar horsepower at 41 mph.

Big Boys were over 132 feet long, 11 feet wide, and 16 feet tall. They weighed nearly 1,200,000 pounds. These locomotives were designed to operate safely and smoothly at 80 mph, but rarely exceeded 60 mph during their working lives.

Engine 4014, serial number 69585, was one of an order for 20 locomotives (4000-4019), built by ALCO (American Locomotive Company) in 1941. They cost $265,000 ($4,921,000 in 2021 dollars) each. They were so successful that five more joined the roster in 1944.

End of an Era

Prior to World War II, most modern steam engines remained in service for 40 or more years, but diesel locomotives proved to be cheaper to maintain and their use eliminated coaling facilities and the need for vast quantities of water.

Massive diesel orders from four domestic builders in the 1950s doomed the Big Boys, which pulled their last revenue trains in mid-1959.

Because of their significance, eight of them were donated to museums in the early 1960s. One of those eight Big Boys donated to museums, Engine No. 4014, was reacquired and put back on the rails.

For more information, visit www.up.com/heritage/ steam/schedule/index.htm for the complete schedule, display locations and times and important safety information.