Union Pacific Big Boy
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The Union Pacific Big Boy is a type of simple articulated 4-8-8-4 steam locomotive manufactured by the American Locomotive Company between 1941 and 1944 and operated by the Union Pacific Railroad in revenue service until 1959.
|Union Pacific Big Boy|
|Cost to build US$ 265,000 in 1941, equivalent to $4,513,993 in 2018|
The 25 Big Boy locomotives were built to haul freight over the Wasatch mountains between Ogden, Utah, and Green River, Wyoming. In the late 1940s, they were reassigned to Cheyenne, Wyoming, where they hauled freight over Sherman Hill to Laramie, Wyoming. They were the only locomotives to use a 4-8-8-4 wheel arrangement: 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 a Union Pacific executive, the class series originally was to have been called the "Wasatch". One day, however, 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 it has stuck ever since.
Eight Big Boys survive today, most on static display at museums across the country. One locomotive, No. 4014, was re-acquired by the Union Pacific in 2013 to be restored to operating condition. The locomotive was restored in May 2019 and made its first runs that same month, becoming the largest and most powerful operational steam locomotive in the world.
In 1936, Union Pacific introduced the Challenger-type (4-6-6-4) locomotives on its main line over the Wasatch Range between Green River and Ogden. For most of the route, the maximum grade is 0.82% in either direction, but the climb eastward from Ogden, into the Wasatch Range, reached 1.14%. Hauling a 3,600-short-ton (3,300 t; 3,200-long-ton) freight train demanded double heading and helper operations, and adding and removing helper engines slowed operations.
To eliminate the need for double heading and helper operations, Union Pacific decided to design a new locomotive. For such a locomotive to be worthwhile, it would have to be faster and more powerful than slower locomotives like earlier compound 2-8-8-0s that UP tried after World War I. To avoid locomotive changes, the new class would need to pull long trains at a sustained speed of 60 miles per hour (100 km/h) once past mountain grades. In fact, it was designed so that it could travel smoothly and safely at 80 miles per hour (130 km/h) — even though it was not intended to be used that fast.
Led by Otto Jabelmann, the head of the Research and Mechanical Standards section of the UPRR (Union Pacific Railroad) Mechanical Department, the UP design team worked with ALCO (the American Locomotive Company) to re-examine their Challenger locomotives. The team found that Union Pacific's goals could be achieved by enlarging its firebox to about 235 by 96 inches (5.97 m × 2.44 m) (about 150 sq ft or 14 m2), increasing boiler pressure to 300 psi, adding four driving wheels, and reducing the size of the driving wheels from 69 to 68 in (1,753 to 1,727 mm) on a new engine. The new locomotive was carefully designed not to exceed an axle loading of 67,800 lb, and achieved the maximum possible starting tractive effort with a factor of adhesion of 4.0.
The Big Boys were articulated, like the Mallet locomotive design, though lacking the compounding of the Mallet. They were built with a wide margin of reliability and safety, and normally operated well below 60 miles per hour (100 km/h) in freight service. Peak horsepower was reached at about 41 mph (66 km/h). The maximum drawbar pull measured during 1943 tests was 138,000 lbs while starting a train.
The Big Boy has the longest engine body of any reciprocating steam locomotive, longer than two buses. It was likely the heaviest steam locomotive ever built: the 772,250-lb engine and 436,500-lb tender together outweighed a Boeing 747. There is some speculation that the first series of Chesapeake and Ohio 2-6-6-6 “Allegheny” locomotives, built by the Lima Locomotive Works in 1941, may have weighed as much as 778,200 lbs, exceeding the Big Boys, but subsequent re-weighs of early-production H8s, under close scrutiny by the builder and the railroad, found them to be less than 772,250 lbs.
The American Locomotive Company manufactured 25 Big Boy locomotives for Union Pacific; two groups of ten in 1941 and one group of five in 1944.
|Class||Quantity||Serial Nos.||Year built||UP No.||Notes|
|4884-1||20||69571-69590||1941||4000-4019||No. 4005: converted to oil fuel in 1946 and reverted to coal in 1948. No. 4019: given experimental smoke deflectors in 1944-45, later removed. No. 4014: in excursion service since May 2019. Nos. 4004, 4005, 4006, 4012, 4017 and 4018 on display in various locations.|
|4884-2||5||72777–72781||1944||4020-4023||No. 4023 on display in Omaha.|
The Big Boy locomotives had large grates to burn the low-quality bituminous coal supplied by Union Pacific-owned mines in Wyoming. Coal was carried from the tender to the firebox by a stoker motor: a steam engine that drove an Archimedes’ screw.
As an experiment, No. 4005 was converted to burn oil. Unlike a similar effort with the Challengers, the conversion failed due to uneven heating in the Big Boy's large, single-burner firebox. The locomotive was converted back to coal firing in 1948. No. 4014 was successfully converted to oil during its restoration. Another short-term experiment was the fitting of smoke deflectors on locomotive 4019, similar to those found on the railroad’s FEF Series. These were later removed, as the Big Boys' nozzle and blower in the smoke box could blow smoke high enough to keep engineers’ lines of sight clear.
The locomotives were held in high regard by crews, who found them sure-footed and more “user friendly” than other motive power. They were capable machines; their rated hauling tonnage was increased several times over the years. But postwar increases in the price of coal and labor, along with the advent of efficient, cost-effective diesel-electric power, spelled the end of their operational lives. Nonetheless, they were among the last steam locomotives withdrawn from service on the Union Pacific. The last revenue train hauled by a Big Boy ended its run early in the morning on July 21, 1959. Most were stored operational until 1961 and four remained in operational condition at Green River, Wyoming until 1962. Their duties were assumed by diesel locomotives and gas turbine-electric locomotives.
Accidents and incidentsEdit
- On April 27, 1953, No. 4005 was pulling a freight train through southern Wyoming when it jumped a switch track at 50 mph (80 km/h), throwing the engine onto its left side and derailing its tender and the first 18 freight cars of its 62-car train. The engineer and fireman were killed on impact; the brakeman died of severe burns in a hospital a few days later. The tender destroyed the cab of the locomotive, and the loads from the 18 derailed cars were scattered. Despite the relatively heavy damage, the locomotive was repaired by Union Pacific at its Cheyenne facility and returned to service.
- On May 16, 2019, No. 4014 derailed while entering the yard at Rawlins, Wyoming; it was returned to the rails within three hours.
Just eight of the 25 Big Boy locomotives survive. Seven are on static display: 4005 and 4017 are displayed indoors while the other five are outdoors without protection from the elements. An eighth, No. 4014, has been restored to operating condition by Union Pacific as part of its steam program.
The surviving Big Boys and their locations are:
- 4004: Holliday Park, Cheyenne, Wyoming ( ).
- 4005: Forney Transportation Museum, Denver, Colorado ( ). No. 4005 has been displayed in a renovated building since January 2001.
- 4006: Museum of Transportation, St. Louis, Missouri ( ).
- 4012: Steamtown National Historic Site, Scranton, Pennsylvania ( ). After retiring in 1962, No. 4012 was on display at Steamtown, USA in Bellows Falls, Vermont, until 1984, when it was moved to Scranton, Pennsylvania No. 4012 is displayed outdoors because it is too large for Steamtown's turntable and roundhouse. Steamtown staff believe No. 4012 could be restored to working order but recommended first determining whether surrounding "track, switches, culverts, trestles, bridges, wyes, turntables and other facilities [could] bear her great weight".
- 4014: Union Pacific Railroad, Cheyenne, Wyoming ( ). Long displayed at Fairplex RailGiants Train Museum in Pomona, California, No. 4014 was reacquired and restored to operational shape by Union Pacific, then placed in excursion service in May 2019 at its new home in Cheyenne, Wyoming, as the largest, heaviest, and most powerful operational steam locomotive in the world.
- 4017: National Railroad Museum, Green Bay, Wisconsin ( ). Displayed in a climate-controlled shed.
- 4018: Museum of the American Railroad, Frisco, Texas ( ). No. 4018 was moved to its current location from the museum's former location in Dallas, Texas, by rail on August 25, 2013.
- 4023: Kenefick Park, Omaha, Nebraska ( ). The only Big Boy known to have been moved by highway.
Notes and referencesEdit
- Peck, Combes & Augur 1950, pp. 501, 519, 523, 545.
- Elliott, Dan (April 15, 2014). "Huge Big Boy steam locomotive coming back to life". Yahoo! News. Associated Press. Retrieved April 15, 2014.
- "Challenger No. 3985". Union Pacific. Archived from the original on May 1, 2019. Retrieved May 23, 2019.
- Morrison, Tom (2018). The American Steam Locomotive in the Twentieth Century (1st ed.). McFarland & Company. pp. 533–534. ISBN 978-1-4766-6582-5.
- "Union Pacific No. 4014" (PDF). RailGiants Train Museum. The Railway and Locomotive Historical Society, Southern California Chapter. August 2014. Archived from the original (PDF) on July 30, 2016. Retrieved May 23, 2019.
- Kratville, William (1972). Big Boy. Kratville Publications.
- Gruver, Mead (May 8, 2019). "Refurbished 'Big Boy' locomotive weighs more than a Boeing 747". The Associated Press. USA Today. Archived from the original on June 8, 2019. Retrieved June 12, 2019.
- Huddleston, Eugene (December 1998). "Doctoring the Scales: The Case of the Overweight Alleghenies". Trains. Vol. 58 no. 12. pp. 78–85.
- "Union Pacific 4-8-8-4 "Big Boy" Locomotives in the USA". www.steamlocomotive.com. Retrieved 2019-06-05.
- Wrinn, Jim (February 15, 2018). "Where to find Big Boy locomotives". Trains. Archived from the original on September 28, 2018. Retrieved June 16, 2019.
- "Big Boy No. 4014". www.up.com. Retrieved 2019-06-05.
- "DISASTER ON THE RAILS: The Wreck of the 4005". Forney Transportation Museum. Archived from the original on September 24, 2018. Retrieved June 14, 2019.
- Wrinn, Jim (May 16, 2019). "Big Boy stubs its toe with derailment". Trains. Archived from the original on May 22, 2019. Retrieved June 9, 2019.
- Cobb, Debbie (May 17, 2019). "Big Boy Derailed On Way To Laramie, Back On Schedule". KCGY. Archived from the original on May 17, 2019. Retrieved June 9, 2019.
- Chappell, Gordon. "Union Pacific Railroad No. 4012". Steam Over Scranton: Special History Study, American Steam Locomotives. National Park Service. Archived from the original on 2012-08-13. Retrieved March 13, 2012.
- "Steamtown's Locomotives and Cars". Steamtown National Historic Site. National Park Service. Retrieved March 13, 2012.
- "A Look Inside the Spine of the 'Big Boy'". www.up.com. Retrieved 2019-06-05.
- Peck, C. B.; Combes, C. L.; et al., eds. (1950). 1950-52 Locomotive Cyclopedia of American Practice (Fourteenth ed.). New York: Simmons-Boardman.
- Bush, John E.; Ehernberger, James L. (1996). Union Pacific Steam Big Boy Portraits (1st ed.). Challenger Press. ASIN B0027ZOGLA.
- Reisdorff, James J. (2007). The Big Legacy of the Union Pacific Big Boy: Why Railfans Still Love the "World's Largest" Steam Locomotive (1st ed.). South Platte Press. ISBN 978-0942035735.