Union Pacific's 4-8-8-4 Big Boy #4004 is on display in Holliday Park, Cheyenne, WY, at 17th and Morrie Avenues.
Cheyenne is also home to the Cheyenne Depot Museum, which houses Union Pacific's Heritage fleet, including Challenger #3985 and FEF-3 #844, both of which are regularly steamed. UP T-57 #1242 is on display nearby in the Cheyenne Botanic Gardens. You can see photos of it on the UP #1242 page of this website.
Thirty-five miles west, you can also visit the Ames Monument, erected in 1882 to commemorate Oakes Ames and Oliver Ames Jr's role in building Union Pacific's part of the transcontinental railway. You can see photos at the Ames Monument page of this website.
#4004 is one of twenty "Class 1" Big Boys built in 1941 (#4000-#4019). Five more Big Boys (#4020-#4024), designated "Class 2", were built in 1944.
Coal burners operating at a boiler pressure of 300 psi, both classes delivered 135,375 lbs tractive effort.
#4004 is one of eight surviving Big Boys, twenty-five of which were built by Alco to a design by Union Pacific's Department of Research and Mechanical Standards. They were designed to handle traffic on heavy grades, particularly on the Ogden-Wahsatch district, but also on Sherman Hill just west of Cheyenne. You can see more Big Boys on the Southern California RLHS page of this website, the Kenefick Park page, the St. Louis Museum of Transportation page, the Museum of the American Railroad page, the National Railroad Museum page and the Steamtown page.
Big Boys proved eminently up to the challenge they were designed to meet, although their arrival on the cusp of increasing dieselisation by the Union Pacific meant they had a relatively short operational life: the last revenue freight hauled by a Big Boy was in July 1959, and most were retired in 1961.
#4004 made its last run on 31st October 1958 and then went into storage before being officially retired in 1962. The following year, it was donated to the City of Cheyenne, and was moved to Holliday Park on 28th June 1963.
The front end of a Big Boy is an impressive thing. The smoke box was one of the largest ever applied to a locomotive, and the entire end is hinged so that it could be opened in just thirty minutes by one workman. As one of the first series, built in 1941, #4004 originally had finned after coolers fitted to the handrails. These were soon removed because of problems with condensation and ice in very cold weather, however, and set behind the pilot front shield. Here, the Buckeye Steel retractable coupler is folded away in the pilot. This was seldom done while the locomotives were in actual operation, as the build-up of grit and winter ice made it difficult to move.
Above, Walschaert valve gear was standard on Union Pacific steam locomotives by the time #4004 was built. Note the wire retainer crosshead nut on the first two photos. This was designed by the Union Pacific to eliminate problems with breaking cotter pins.
The red handles beneath the firebox in the first photo above release the ash pan. Just above that, and slightly to the right, is the foam meter blowdown, which discharged into a spreader box under the cab.
The middle photograph shows the right rear cylinder, steam supply pipe and front Walschaert gear and cylinder.
The last photograph gives a closer view of the front Walschaert gear and cylinder. The black jacket in the centre covers the chain drive to the Nathan lubricator, just out of view on the left.
Above, the centipede tender was fitted with a rigid frame to give necessary support to the massive water and fuel supply. Train control and fire fighting boxes can be seen at the front of the tender on either side. The recessed ladder gave the tender its clean lines.
Will a Big Boy ever steam again?
This is a question guides are regularly asked by visitors to sites where Big Boys are on display, and one which quickens the hearts of railroad enthusiasts the world over. Although there have been plans and rumours over the years, the answer remains "unlikely".
Cost is a major consideration. Most of the surviving Big Boys are on outdoor display, which means they have been exposed to the elements and would require significant investment to make them operable. The most recent (1998) proposal to restore Dallas Age of Steam Museum's #4018, for example, foundered on the estimated $2.5-3 million restoration bill, as well as a lack of interest from promoters in the film it was to star in. You can see #4018 on the Museum of the American Railroad page of this website.
A second major consideration relates to the logistics of operating a 132' long locomotive weighing 1,208,750 lbs. Few locations on the Union Pacific system have wyes or turntables that could accommodate that length, and many tracks, bridges and switches could not handle the weight. To avoid trackside fires and allow access to ready supplies of fuel, a restored Big Boy would also best be converted to an oil burner, but such a conversion was tried in the 1940s on #4005 with little success.
On the other hand, the 121' long, 1,073,900 lb Challenger #3985 was restored to steam by the Union Pacific in 1981. It was converted to burn oil in 1990 despite having a firebox much like a Big Boy's, and it has kept up a regular schedule of excursions, travelling as far as Los Angeles, CA from its base in Cheyenne, WY. It is perhaps a forlorn hope that a Big Boy will steam again but, in the final analysis, with enough money, anything is possible...
Related Links:
UP Big Boy #4004 Location
Trainweb Big Boy Information Center
Train Attractions in Cheyenne
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William Kratville's Big Boy, published by Autoliner in 2004, provides lots of information and some fine photographs of Big Boys in operation (click on the cover to search for this book on Bookfinder.com).
