In 2013, UP re-acquired the locomotive and launched a restoration project at its Steam Shop in Cheyenne, Wyoming. In May 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.[3] It now operates in excursion service for the UP steam program. No. 4014 became the first mainline steam locomotive to be equipped with the positive train control (PTC) system in 2021.
The Big Boy class was developed by Union Pacific and built by the American Locomotive Company (ALCO) in the 1940s to handle the 1.14% eastbound ruling grade of Utah's Wasatch Range.[5] A team led by UP's chief mechanical officer Otto Jabelmann adapted the design of the 4-6-6-4Challenger, enlarging the firebox to about 235 by 96 inches (5.97 m × 2.44 m) (about 155 sq ft or 14.4 m2), lengthening the boiler, adding four driving wheels, and reducing the diameter of the driving wheels from 69 to 68 in (1,753 to 1,727 mm).[2][5]
The Big Boy was articulated like the Mallet locomotive design, although without compounding.[6] It was designed for stability at 80 miles per hour (130 km/h), allowing for a wide margin of reliability and safety, as steam locomotives normally operated well below that speed in freight service.[7] Peak power was reached around 35 mph (56 km/h); optimal tractive effort was maintained up to around 10 mph (16 km/h).[7] It is longer than two city buses and weighs more than a Boeing 747.[8]
ALCO built No. 4014 in November 1941 at a cost of $265,174 ($5,493,000 in 2023[9]) and delivered it the following month to Union Pacific, which placed it in revenue service.[2][5] No. 4014 was part of the first group of 20 Big Boys, called 4884–1.[1] Designed to haul 3,600-short-ton (3,214-long-ton; 3,266 t) freight trains over the Wasatch Range, the Big Boys routinely pulled freight trains of up to 4,200 short tons (3,750 long tons; 3,810 t).[2] During a test on April 2, 1943, No. 4014 pulled 65 freight cars between Ogden, Utah, and Evanston, Wyoming, generating a maximum of 5,530 hp (4,120 kW).[5][10]
No. 4014's last routine repairs took place in 1956.[11] The locomotive completed its final revenue run on July 21, 1959, just hours before the last revenue run by any Big Boy.[2] It had traveled 1,031,205 miles (1,659,564 km) during its revenue service.[2][5] Union Pacific retired No. 4014 on December 7, 1961.[7] All of the remaining Big Boys were retired by 1962, when their duties were taken over by diesel locomotives and gas turbine-electric locomotives (GTELs).[2][12] That same year, Union Pacific donated No. 4014 to the Southern California chapter of the Railway & Locomotive Historical Society in Pomona, California, where it became one of the eight Big Boys preserved around the United States.[7][13]
"No other railroad has retained its historical equipment or honored its American roots like Union Pacific. Our steam locomotive program is a source of great pride to UP employees past and present. We are very excited about the opportunity to bring history to life by restoring No. 4014."
In late 2012, Union Pacific officials announced that they intended to obtain a Big Boy locomotive for restoration to operational condition for excursion service.[14] On July 23, 2013, UP announced that the Southern California Chapter of the Railway & Locomotive Historical Society (R&LHS) had agreed to return No. 4014 to UP.[15][a]
On November 14, 2013, No. 4014 began its journey to the UP Steam Shop in Cheyenne.[18][19] It was pulled from its display site at the museum, on temporary track, through the adjacent parking lot.[18][19] On January 26, 2014, No. 4014 was pulled from the Los Angeles County Fairplex to the Covina station on Metrolink trackage by No. 1996, an SD70ACe diesel locomotive painted in Southern Pacific colors.[20][21] It presently arrived at UP's West Colton Yard in Bloomington, California,[22] where it sat on display until April 28, when it began its journey to Cheyenne.[23] After arriving at the Steam Shop's roundhouse on May 8,[24] No. 4014 sat largely idle for two years while the UP steam crew worked to overhaul No. 844.[25][26] The Steam Shop also used the time to expand and upgrade its facilities to accommodate a Big Boy.[27]
In August 2016, a month after No. 844's repairs and inspection were complete, UP officials announced that the restoration work of No. 4014 had begun under Heritage Fleet Operations director Ed Dickens.[28][29] By early 2017, the locomotive had been completely disassembled.[30] Some new parts were fabricated, including the rod brasses, top boiler check valve, and lubricator check valves.[30] The driving wheels were sent to be repaired by the Strasburg Rail Road in Strasburg, Pennsylvania, for crankpin and axle work as well as installing new tires.[31][32]
The work included one major alteration: converting the coal-burning locomotive to run on No. 5 fuel oil.[7] This was done by replacing the firebox grates with a fire pan and an oil burner.[33] This made No. 4014 the first Big Boy to undergo a coal-to-oil conversion since No. 4005, which ran on oil from 1946 until it was converted back to coal in 1948 due to uneven heating in its large, single-burner firebox.[13][34] No. 4014's old firebox grates were salvaged and used on the Milwaukee Road 261 steam locomotive.[35][b]
In March 2018, it was reported that No. 4014 was being reassembled;[33] ten months later, the locomotive's restoration was nearly finished.[37] On February 6, 2019, No. 4014's boiler passed a hydrostatic test and the locomotive was successfully test-fired on April 9.[38][39][40] Around 9 p.m. on May 1, 2019, No. 4014 moved under its own power for the first time in almost 60 years.[41] The following evening, the locomotive made its first test run, from Cheyenne to Nunn, Colorado.[42]
Once restored, No. 4014 joined the railroad's never-retired No. 844 steam locomotive in excursion service.[43][44] It also became the world's largest operational steam locomotive, displacing No. 3985.[45] Additionally, No. 3985's original tender, No. 25-C-311, is connected to No. 4014 to meet the restoration deadline.[46][47] In January 2020, Union Pacific officials announced that the UP Steam Team would operate just two steam locomotives—Nos. 844 and 4014—and would retire No. 3985, which was in poor mechanical condition.[45][46]
In May 2022, the Railroading Heritage of Midwest America (RRHMA) in Silvis, Illinois, announced plans to convert No. 4014's original tender, No. 25-C-116, to carry fuel oil instead of coal.[58] The tender is to be reconnected with No. 4014 and the No. 25-C-311 tender will be reconnected to the No. 3985 locomotive,[58] which is to be donated by UP to the RRHMA.[59][60] In late July 2022, No. 4014 pulled the Museum Special excursion between Cheyenne and the Denver Union Station to benefit the Union Pacific Railroad Museum.[61][62][c] On September 14, 2022, No. 4014 was fired up to move Union Pacific 5511 from the Cheyenne roundhouse and around the yard for testing before the 2-10-2 locomotive left for the RRHMA two months later.[65][66]
In June 2023, No. 4014 ran from Cheyenne to Omaha, Nebraska, with the Home Run Express Tour, for display at Charles Schwab Field Omaha on June 15-21 and 24-25.[67][68] During the return journey to Cheyenne on June 29, No. 4014 banked a stalled freight train up the grade in Blair, Nebraska.[69] Two cab rides on the July 3 journey from Pine Bluffs, Wyoming, to Cheyenne were sold for $9,500 apiece to benefit the Union Pacific Railroad Museum.[70][d]
Two tours were executed in 2024.[72] The first ran from June 30 to July 26, with stops at the Western Pacific Railroad Museum in Portola, California, on July 10,[73]Roseville, California, on July 12 and 13, and Ogden, Utah on July 20 and 21.[72] The second tour began on August 28 and concluded on October 23; it included stops in Texas, Arkansas, Kansas, and Illinois.[72] On the second tour's journey through Iowa in September, American comedian and former The Tonight Show host Jay Leno hitched a ride on No. 4014 to film the episode for his YouTube web series Jay Leno's Garage.[74]
In December 2018, Union Pacific asked the Federal Railroad Administration (FRA) to exempt UP Nos. 4014 and 844 from federal positive train control (PTC) requirements;[75] three months later, the FRA officials responded that such waivers were not needed.[76]
In 2021, No. 4014 became the first mainline steam locomotive to be equipped with PTC.[77][78] Initially, its PTC display was powered by computers and equipment in its helper diesel locomotive, No. 4015.[78][79] 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.[80]
^No. 261 may be converted to burn oil, depending on the feasibility study and cost-benefit analysis.[36]
^UP originally announced on April 11, 2022, that No. 4014 would tour the Northwestern United States, starting on June 26 in commemoration of UP's 160th anniversary, but the tour was cancelled on April 22 so UP could reduce supply chain congestion.[63][64]
^UP's original plan was to auction off one cab ride.[71] But on June 23, UP informed its Steam Club members that the auction "was manipulated by an individual and did not result in an award to the highest bidder" and that as a result, the museum would sell two tickets, priced at $9,500 each, at 5 p.m. CDT on its website.[70]
^On April 10, 2019, the diesel locomotive numbered 4014 was redesignated as 4479 on the UP active locomotive roster, allowing the "Big Boy" to retain the number.[81][82]