Union Pacific 4014 is a preserved 4884-1 class "Big Boy" type steam locomotive owned and operated by the Union Pacific (UP) as part of its heritage fleet. Built in 1941 by the American Locomotive Company (ALCO) in Schenectady, New York, it was assigned to haul heavy freight trains in the Wasatch mountain range. The locomotive was retired from revenue service in 1959, and donated to the Railway & Locomotive Historical Society in 1961. It was displayed in Fairplex at the RailGiants Train Museum in Pomona, California.
In 2013, UP re-acquired the locomotive and launched a restoration project at its Steam Shop in Cheyenne, Wyoming. In 2019, No. 4014 moved under its own power after sitting dormant for almost six decades, becoming the world's largest operational steam locomotive and the only operating Big Boy locomotive of the eight that remain in existence. In 2021, No. 4014 became the first mainline steam locomotive to be equipped with the positive train control system. It now operates in excursion service for the UP steam program, including a coast-to-coast tour in 2026.
History Design
The Big Boy class was developed by Union Pacific (UP) and built by the American Locomotive Company in the 1940s to handle the 1.14% eastbound ruling grade of Utah's Wasatch Range unassisted. Under the instruction of UP president William M. Jeffers, a team led by UP's chief mechanical officer Otto Jabelmann adapted the design of the 4-6-6-4 Challenger, enlarging the firebox to about (about ), lengthening the boiler, adding four driving wheels, and reducing the diameter of the driving wheels from . Originally, the 4-8-8-4 class was rumored to be called Wasatch, after the Wasatch Mountains, but acquired the Big Boy nickname after an unknown ALCO worker scrawled it in chalk on the smokebox door of No. 4000, the first of its class.
The Big Boy was articulated like the Mallet locomotive design, although without compounding. It was designed for stability at , allowing for a wide margin of reliability and safety, as steam locomotives normally operated well below that speed in freight service. Peak power was reached around ; optimal tractive effort was maintained up to around . It is longer than two city buses and weighs more than a Boeing 747. The locomotives were equipped with a Hancock long-bell 3-chime "steamboat" whistle.
Revenue service
ALCO built No. 4014 as part of the first group of 20 Big Boys, called 4884–1. The locomotive was completed in November 1941 at a cost of $265,174 ($ in ) and delivered to UP a month later. In revenue service, the Big Boys were initially assigned to haul freight trains between their home bases of Ogden, Utah, and Green River, Wyoming, allowing the Challengers to be reassigned to wartime traffic east of Green River towards Cheyenne, Wyoming. They proved better than expected: designed to haul freight trains over the Wasatch Range, they routinely hauled up to . During a test on April 2, 1943, No. 4014 pulled 65 freight cars between Ogden and Evanston, Wyoming, generating a maximum of against a three-unit diesel.
Around 1944, wartime traffic was at its peak and the 4884–1 group were due for heavy shopping. UP ordered five more Big Boys, Nos. 4020-4024, which were classified as 4884-2 and built at a cost of $319,600 each. At this point, the Big Boys operated from Green River towards Rawlins, Laramie, and Cheyenne. Around 1948, all of them were based in Cheyenne for revenue runs to Green River; Denver, Colorado; and occasionally Ogden. By 1950, the Big Boys occasionally worked east towards North Platte, Nebraska, from Cheyenne.
No. 4014's last routine repairs took place in 1956. During the work, the locomotive's original tender, 25-C-115, was swapped with No. 4015's 25-C-116. No. 4014 also received a driving rod bearing part from No. 4002. On July 20, 1959, No. 4014 left on its final revenue run, departing Laramie at 10:15 p.m. and arriving in Cheyenne the next day at 1:50 a.m. It had traveled during its revenue service. Afterwards, the Big Boys were stored in operational condition in Wyoming: No. 4014 and most of the Big Boys in Cheyenne, four in Green River. The Big Boys' duties were taken over by EMD GP9 diesels and gas turbine-electric locomotives (GTELs); 17 of them were retired from the operating roster and cut up for scrap in 1961 and 1962.
Preservation
Eight of the popular locomotives were salvaged for preservation. Among them was No. 4014, which UP agreed to donate to fulfill an October 18, 1961, request from the Southern California Chapter of the Railway & Locomotive Historical Society (R&LHS) in Pomona, California. Its builder's plates had been stolen, so the locomotive was fitted with two replicas of No. 4001's plates with the serial number 69572 and the September 1941 build date. On December 7, No. 4014 was retired from the operating roster. It left for Pomona on December 29 and was transported by freight train with brief stops in Las Vegas, Nevada, and Yermo, California. On January 8, 1962, the locomotive arrived in Pomona, where Pacific Electric moved it into the Los Angeles County Fairgrounds (LACF).
UP's last new passenger steam locomotive, FEF-3 No. 844, had operated in excursion service since 1960, making UP the only Class I railroad in America still running steam locomotives. In 1981, UP's steam program added Challenger No. 3985, which along with No. 844, would be the program's marquee locomotive for more than three decades. In 1989, when the Southern California Chapter of the R&LHS moved their RailGiants museum within the fairgrounds, No. 4014 was pushed and pulled across the parking lot.
As the years passed, some speculated that one of the eight preserved Big Boys could be restored to operational condition. A year after No. 3985 was removed from service in 2010, a West Coast businessman proposed to fund a multi-million dollar UP effort to restore a Big Boy. This proposal was accepted by Ed Dickens, the senior manager of UP's heritage fleet operations.
Ownership transfer and restoration
In late 2012, UP officials announced that they might restore a Big Boy locomotive. The Southern California Chapter of the R&LHS said they had conducted preliminary discussions with the railroad about returning No. 4014, whose boiler barrel was in excellent mechanical condition and whose display in temperate Southern California had limited rust and other deterioration. On July 23, 2013, UP officials announced that the deal was done. No. 4014's journey to the UP Steam Shop in Cheyenne began on November 14, when Dickens and his team, along with lead journeyman machinist Austin Barker, used a front-end loader to tow the locomotive from its display site at the Fairplex onto a short section of temporary track. It took nearly a month to pull the locomotive across a mile of the LACF parking lot and National Hot Rod Association property, repositioning 40-foot sections of temporary track in leapfrog fashion, to reach a UP holding track near Arrow Highway and White Avenue.
On January 26, 2014, No. 4014 was pulled onto Metrolink trackage and into Covina station by No. 1996, an SD70ACe diesel locomotive painted in Southern Pacific colors. It presently arrived at UP's West Colton Yard in Bloomington, California, for further repairs. On April 28, it began its journey to Cheyenne behind an SD70M that shared the same number as the Big Boy. Another SD70M, No. 4884, was behind the Big Boy to help brake when descending the hill. Its number was also a nod to the Big Boy's wheel arrangement. On May 8, No. 4014 arrived at the Steam Shop's roundhouse. It sat largely idle for two years while the UP Steam Team crew worked to overhaul No. 844 and to expand and upgrade its facilities to accommodate the Big Boy.
In July 2016, after No. 844's repairs and inspection were complete, the restoration work of No. 4014 began under Dickens' supervision. The UP Steam Team used No. 844 to move the Big Boy onto the turntable, and turned it to face west. They separated the locomotive from its tender and moved it into the main Steam Shop. They began a through boiler inspection: removing the tubes, flues, and superheaters, testing all of the bolts and rivet, checking the metallurgy, inspecting the seams of the boiler courses, and performing an ultrasonic test to determine the thickness of the boiler shell and firebox walls. In December 2016, the Steam Team hired a derailment-cleanup company to use two heavy-duty cranes to lift No. 4014's boiler, allowing the two sets of articulated frames to be separated from the rest of the locomotive.
By early 2017, the Big Boy had been completely disassembled. Some new parts were fabricated, including the rod brasses, top boiler check valve, and lubricator check valves. The leading wheels, driving wheels, and trailing wheels were sent to the Strasburg Rail Road in Strasburg, Pennsylvania, for repairs and upgrades. The drivers were given new tires, while the roller bearings on the axles of the leading and trailing wheels were replaced. The axles, crankpins, and eccentric cranks, which were part of the driving gear made to transmit the wheels' movement, were also replaced. The two cross-compound air pumps were rebuilt by the Back Shop Enterprises in Wheat Ridge, Colorado. Barker, who had become the general foreman of UP's heritage fleet operations in 2015, used a computer-aided design (CAD) program to analyze how No. 4014's mechanical parts move and interact with adjacent components.
The restoration work included one major alteration: converting the coal-burning locomotive to run on No. 5 fuel oil by replacing the firebox grates with a fire pan and an oil burner. The data lettering on the sides of No. 4014's cab was changed from "MB", denoting an MB-type mechanical stoker, to "DB", for Dickens/Barker, crediting Dickens and Barker for converting the locomotive to run on oil. No. 4014 was the first Big Boy to undergo a coal-to-oil conversion since No. 4005, which ran on oil from 1946 until it was reconverted to coal in 1948 due to uneven heating in its large, single-burner firebox. To meet the restoration deadline, No. 4014 was mated with tender No. 25-C-311, which originally belonged to No. 3985. No. 4014's old firebox grates were salvaged and used on the Milwaukee Road 261 steam locomotive.
In March 2018, it was reported that No. 4014 was being reassembled; In June 2018, all of the wheels returned from Strasburg. By December 2018, the locomotive's restoration was nearly finished. The locomotive was moved outside to be reunited with its newly rebuilt articulated frames. On February 6, 2019, No. 4014's boiler passed a hydrostatic test and the locomotive was successfully test-fired on April 9. Around 9 p.m. on May 1, 2019, No. 4014 moved under its own power for the first time in almost 60 years. The next evening, the locomotive made its first test run, from Cheyenne to Nunn, Colorado. One estimate put the cost of restoration at $4 million or more.
Positive train control In December 2018, Union Pacific asked the Federal Railroad Administration (FRA) to exempt UP Nos. 4014, 3985, and 844 from federal positive train control (PTC) requirements; three months later, the FRA officials responded that such waivers were not needed.
In 2021, UP would equip No. 4014 with PTC anyway, making it the first mainline steam locomotive to be so equipped. Initially, its PTC display was powered by computers and equipment in its helper diesel locomotive, UP SD70M No. 4015. In May 2024, PTC equipment was installed in a cabinet in the tender, and a third dynamo added to the locomotive to provide electrical power, allowing No. 4014 to run without a diesel helper.
Excursion service