Union Pacific No. 4014, famously known as "Big Boy," is one of the largest and most powerful steam locomotives ever built. Manufactured by the American Locomotive Company (ALCO) in November 1941, it is a 4-8-8-4 articulated locomotive designed to haul heavy freight over the Wasatch Mountains in Utah. No. 4014 served the Union Pacific Railroad until its retirement from active duty in 1961.
Following its retirement, No. 4014 was donated to the RailGiants Train Museum in Pomona, California, where it remained on static display for over five decades. In 2013, the Union Pacific Railroad reacquired the locomotive and transported it back to their steam shop in Cheyenne, Wyoming. After a complex and extensive restoration, No. 4014 returned to steam in May 2019, becoming the only operational Big Boy in the world.
Today, Union Pacific No. 4014 operates as part of UP’s heritage fleet, serving as a moving tribute to America's railroading legacy and thrilling railfans across the country during its special excursion runs.
History[]
Union Pacific Railroad No. 4014, known as "The Big Boy," is a massive four-cylinder articulated steam locomotive of the 4-8-8-4 wheel arrangement, owned and operated by the Union Pacific Railroad. Built by the American Locomotive Company (ALCO) in November 1941, No. 4014 was part of a series of Big Boy locomotives designed to address the limitations of the earlier 4-6-6-4 Challenger class engines, providing greater power and efficiency for hauling heavy freight over steep mountain grades. No. 4014 made its final run in regular service on July 21, 1959, as did the rest of the Big Boy fleet, and was officially retired on December 7, 1961. It was later donated to the Railway & Locomotive Historical Society and placed on display at the RailGiants Train Museum in Pomona, California. Capable of reaching speeds up to 80 mph and producing a massive 6,290 horsepower, No. 4014 remains an icon of American steam power and railroad engineering.[1][2][3][4][5][6][7][8]
Union Pacific No. 4014 arrived at its display location in Pomona, California in January 1962, where it was showcased at the Fairplex and the RailGiants Train Museum for over five decades. In 1989 or 1990, while the chapter was relocating its collection from the original display area behind the horse barns to a new site near the main parking lot, No. 4014 unexpectedly surprised the movers. During the transfer, the locomotive began to move more easily than anticipated and unexpectedly rolled away, colliding with the tender of the AT&SF Hudson 3450. The two locomotives were left in that position overnight while the team planned how to reposition them the following day. However, when they returned in the morning, they discovered that 3450 had slowly rolled off the temporary track sections used during the move and had partially sunk into the dirt.
First Restoration - Acquired by Union Pacific[]
On November 14, 2013, Union Pacific announced its plan to reacquire No. 4014 for restoration. The locomotive began its move out of the RailGiants Train Museum on January 26, 2014, and arrived at Union Pacific’s Steam Shop in Cheyenne, Wyoming, on May 8, 2014. To fill its spot at the museum, Union Pacific provided SD40-2 No. 3105 along with a boxcar and a caboose. After completing a full overhaul of Union Pacific No. 844 in July 2016, restoration work on No. 4014 officially began on August 11, 2016. Following several years of meticulous and extensive work, No. 4014 was brought back to life and returned to service. It joined No. 844, known as the “Living Legend,” as part of Union Pacific’s heritage excursion fleet. Once operational, No. 4014 became the largest, heaviest, and most powerful steam locomotive in active service, eventually surpassing and replacing Union Pacific Challenger No. 3985. Its revival marked a monumental moment in preserving one of the most iconic steam locomotives in American railroading history.[1][2][3][4][5][6][7][8]
The restoration of Union Pacific No. 4014 was completed in late April 2019, just in time to celebrate the 150th anniversary of the Transcontinental Railroad in May 2019, as well as the 75th anniversary of No. 844, the “Living Legend.” On April 27, 2019, 4014 successfully lit its oil fire, marking the first time a Big Boy had fired up in 60 years and making it the first Big Boy to be converted to oil-firing. 4014’s inaugural test run took place on May 2, 2019, followed by its first excursion run on May 4, 2019, where it doubleheaded with No. 844 to commemorate the Transcontinental Railroad’s anniversary. By January 2020, 4014 officially replaced Challenger No. 3985 in Union Pacific’s steam excursion program due to 3985’s declining mechanical condition. In August 2021, 4014 made history once again by becoming the first steam locomotive in the United States to be equipped with Positive Train Control (PTC) technology, despite the Federal Railroad Administration having informed Union Pacific in late 2018 that installing PTC on their steam locomotives was not mandatory at the time.[1][2][3][4][5][6][7][8]
In June 2022, plans were announced for No. 4014 to embark on a West Coast tour through the Pacific Northwest starting June 26th, including a highly anticipated meetup in Portland, Oregon with Southern Pacific No. 4449, known as “The Daylight.” However, due to freight traffic congestion caused by ongoing supply chain issues, the tour was ultimately cancelled. Instead, 4014 traveled to Denver, Colorado, arriving on July 28th, where it was put on public display under steam the following day. On July 30th, the locomotive led a special excursion hosted by the Union Pacific Museum, returning to Cheyenne, Wyoming.
On June 7, 2023, it was announced that No. 4014 would embark on the Home Run Express Tour, running an excursion from Cheyenne, Wyoming, to Omaha, Nebraska. While in Omaha, the locomotive was placed on public display under steam at Charles Schwab Field before returning to Cheyenne in early July. On June 29, 2023, during its journey back, 4014 assisted a stalled Union Pacific freight train by coupling onto the rear of the train to help move it forward.
In 2024, two major tours for 4014 were planned. The first, known as the "Westbound Tour," took place during the summer, with stops in Roseville, California on July 12th and 13th, and Ogden, Utah on July 20th and 21st. The locomotive departed Cheyenne on June 30th for this tour. The second tour, called the "Heartland Circle Trip," ran from late August through late October, covering stops across Nebraska, Iowa, Illinois, Missouri, Arkansas, Texas, Oklahoma, Kansas, and Colorado. During this tour, former NBC Tonight Show host and comedian Jay Leno had the opportunity to ride in the cab of 4014 while filming an episode of his show, "Jay Leno’s Garage."
Reports have also indicated that siding improvements are underway in Idaho, which could increase the likelihood of 4014 operating another Pacific Northwest tour around 2026, potentially including stops in Boise and Portland.
In July and September-October 2025, 4014 participated in short trips out of Denver similar to those in 2022, this time accompanied by the Abraham Lincoln Unit 1616 (formerly No. 4015) in the former, and No. 4404 in the latter. Also in the latter, 4014 was fitted with smoke deflectors, becoming the second Big Boy to be fitted with smoke deflectors, the other being 4019. For America’s 250th anniversary in 2026, Union Pacific CEO Jim Vena said that he wants 4014 to make its first coast-to-coast tour.
Trivia[]
- On May 2, 2019, 4014 successfully made its first run under its own steam, officially gaining and reclaiming the title of "Largest Operating Steam Locomotive in the World", which was originally held by Challenger locomotive 3985. It then made its first excursion, dubbed The Great Race to Ogden, on May 4, 2019, double-headed with Living Legend 844.
- 4014 was previously renumbered to UP x4014 because of an EMD SD70M diesel locomotive that previously had 4014's number. That SD70M has now been renumbered to 4479 to allow the Big Boy to be numbered back to simply 4014.
- In December 2018, Union Pacific requested from the Federal Railroad Administration (FRA) waivers to exempt 4014, 844, and 3985 from federal Positive Train Control (PTC) requirements. In February 2019, the FRA officials responded that such waivers were not needed. However, 4014 was later successfully fitted with PTC technology in August 2021 before its big 2021 excursion tour.
- 4014 currently uses the oil tender from now retired 3985 and is the first Big Boy to be successfully converted to burn oil, unlike sibling Big Boy locomotive 4005 during its revenue service career with the Union Pacific.
- 4014 is temporarily using 3985's tender until its original tender is restored by the Railroading Heritage of Midwest America (RRHMA) in Silvis, IL, at which point, it will get its original tender back in exchange for 3985's tender.
- In April 2024, 4014's original tender was sandblasted and received a new coat of primer by the RRHMA's shop complex and is being prepared for conversion from carrying coal to oil.
- The locomotive can be seen in Herron Rail Video's Union Pacific Streamliners and Classic Steam in 1950s revenue service, being towed to the RailGiants Museum in Pomona, California during the 1960s, and on present day excursion service.
- In 2022, 4014 was fitted with a new dual-beam headlight and its whistle was swapped out with 844's whistle. However, in 2023, 4014 was given back its excursion service whistle.
- Said whistle from 844 is 4014's regular service whistle, which it wore during its freight career.
- On June 29, 2023, 4014 assisted a stalled Union Pacific freight train by coupling behind the rear end of the train.
- In May 2024, 4014 was fitted with a third dynamo to power the PTC equipment. Thanks to that 4014 doesn't need an diesel assistance during excursions anymore (However it will still run with diesel assistance as a backup engine or additional braking power).
- In September 2025, 4014 was fitted with smoke deflectors, becoming the second Big Boy to be fitted with smoke deflectors, the other being 4019.
- 4014 has appeared in the videos:
- 1. Last of the Giants Volume 3-Sherman Hill,
- 2. Kidsongs-Boppin' With The Biggles,
- 3. Union Pacific Big Boy Collection,
- 4. Big Boys & Challengers,
- 5. Big Boys & Brothers in the '50s,
- 6. Big Boy 4014 Update,
- 7. The Wasatch Grade,
- 8. Return of the Big Boy,
- 9. A Giant Returns,
- 10. Big Boy 4014 West,
- 11. Big Boy Returns to the Mainline,
- 12. Big Boy 4014 Returns to Steam,
- 13. Big Boy Back in Steam,
- 14. Big Boy On Tour,
- 15. Trains Magazine's Best of 2019,
- 16. Steam Across America,
- 17. Great American Steam Locomotives: Articulateds,
- 18. Southwest Big Boy,
- 19. Big Boy-Greetings From Kansas City,
- 20. Steamin' in 2019,
- 21. Steamin' in 2021,
- 22. Steamin' in 2024,
- 25. Year of the Big Boy Trilogy,
- 26. Union Pacific's Sidney Subdivision Parts 1 & 2,
- 27. Union Pacific's Kearney Subdivision,
- 28. Big Boy 4014 Back On Tour 2021,
- 29. Big Boy 4014 Goes to Texas,
- 30. Union Pacific's Pocatello Subdivision Parts 1 & 2,
- 31. Big Boy Tours the Midwest,
- 32. A Northern A Challenger & A Big Boy,
- 33. Big Boy 4014 in the Midwest,
- 34. Union Pacific Railroad Volume 1: Big Boy & Freights in Wisconsin,
- 35. Steam Smoke & Thunder Parts 1 & 2,
- 36. Northwest Shortline & Regional Railroads Volume 1,
- 37. UP 4014: Big Boy in the Midwest,
- 38. Mainline Steam Across the US,
- 39. Search for Steam (the best of 2021),
- 40. EMD at 100,
- 41. Introduction to Steam Locomotives,
- 42. UP 4014: The Great Race Across Texas
- 43. In Search of Steam Volume 3-The Best of 2019
- 44. Articulateds-America's Biggest Steam
- & 45. Train Mountain Triennial 2022
- On one portion of the Big Boy's Hearland Circle Tour in 2024, Former NBC Tonight Show Host & Comedian Jay Leno rode in the cab of 4014 during the filming of an episode of "Jay Leno's Garage".
References[]
- ↑ 1.0 1.1 1.2 https://www.american-rails.com/big.html
- ↑ 2.0 2.1 2.2 https://www.britannica.com/technology/Big-Boy-locomotive
- ↑ 3.0 3.1 3.2 https://www.up.com/heritage/steam/4014/
- ↑ 4.0 4.1 4.2 https://www.up.com/heritage/steam/4014/4014-project/index.htm
- ↑ 5.0 5.1 5.2 http://www.railgiants.org/union-pacific-big-boy.htm
- ↑ 6.0 6.1 6.2 https://www.up.com/cs/groups/public/@uprr/@newsinfo/documents/up_pdf_nativedocs/pdf_up_media_4014_fact_sheet.pdf
- ↑ 7.0 7.1 7.2 https://www.up.com/heritage/steam/schedule/index.htm
- ↑ 8.0 8.1 8.2 https://www.trainchasers.com/up.html