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At the Depot

 "Big Boy"
The Scoop

Southern California Chapter
Railway and Locomotive Historical Society

     Number 4014 is one of twenty "Big Boy" locomotives built for the Union Pacific in 1941.  Five additional locomotives were built in 1945.  With a 4-8-8-4 wheel arrangement, they were the largest steam locomotives ever built.
     The "Big Boys" were originally designed to haul 3,600 ton trains unassisted over the Wasatch Mountains between Ogden, Utah and Evanston, Wyoming on the nation's first transcontinental railroad.  Performance was so good, however, that 4,200 ton trains were hauled regularly.  On level ground, the "Big Boys" could easily do 70 mph.  The maximum horsepower was approximately 6,290 at 35 mph, and the maximum drawbar pull was approximately 135,375 pounds at 10 mph.  On a typical run from Ogden to Evanston, a "Big Boy" would consume 35 tons of coal and 35,000 gallons of water.  In their final years, the "Big Boys" were operated almost exclusively over Sherman Hill between Cheyenne and Laramie, Wyoming.
     Number 4014 performed faithfully to the very end of steam power on the Union Pacific, accumulating 1,031,205 miles in active service.  At 10:15 PM on July 20, 1959, engineer Bruckert eased No. 4014 out of Laramie for its last revenue trip over Sherman Hill.  It arrived in Cheyenne at 1:50 AM on July 21, 1959.  It was followed a few hours later by No. 4015, which completed the last revenue run of a Big Boy locomotive at 7:55 PM on July 21, 1959.  The locomotive was retired in December, 1961 and donated by the Union Pacific Railroad to the Southern California Chapter of the Railway and Locomotive Historical Society in Pomona.
     Eight of the original 25 "Big Boy" locomotives are on display in the United States, making the "Big Boy" the most preserved model of steam locomotives.  Because of the dry weather in Los Angeles, #4014 is in relatively good condition, and very few parts are missing.  The Society is working to remove rust and scale from areas which have suffered water damage, paint these areas to protect them, and eventually do a complete cosmetic restoration.
     Who designed the "Big Boys"?
     During the late 1930's, the Union Pacific often used helpers to move trains from Ogden to Wasatch.  The UP wanted to simplify this move so they asked their "Department of Research and Mechanical Standards" to design a locomotive that could pull a 3,600 ton train unassisted over the 1.14% grade of the Wasatch.
     The designers determined that to pull a 3,600 ton train, a tractive effort of 135,000 lbs. would be needed.  Assuming a factor of adhesion of 4.0, the weight on drivers would have to be 4.0 x 135,000 = 540,000 lbs.  Given an axle loading of 67,500 lbs each, this would require 8 drivers or an x-8-8-x wheel arrangement.  The designers agreed upon the 4-8-8-4 design.  Next, the horsepower and cylinder sizes were computed based on 300 psi boiler pressure.  Although they weren't planning to pull these freight trains at 80 MPH, the DoRMS designed them for 80 MPH in order to have a sufficient factor of safety built into the design.  What resulted is considered by many to be the most successful articulated steam locomotive ever built.  4000 was delivered to Omaha at 6 PM, September 5, 1941.
     Why are they considered the largest?
     When steam locomotives are compared, many different quantities can be considered.  For example, weight, length, horsepower, and tractive effort are all characteristics of how "large" a steam locomotive is.  In each of the above categories, a locomotive "larger" than a "Big Boy" can be found.  However, if one could somehow combine all of these characteristics into a formula which could be used to compute the "largeness" of a locomotive, the Big Boy would most certainly win.
     When did they roam the rails?
     The 25 "Big Boys" were built in two groups.  The first group, called "class 1," were built starting in 1941.  They were numbered 4000 - 4019.  The second group, "class 2," were built in 1944.  They were numbered 4020 - 4024.  The last revenue freight pulled by a "Big Boy" was in July of 1959.  Most were retired in 1961.  The last one was retired in July of 1962.  As late as September, 1962, there were still four operational "Big Boys" at Green River, WY.
     How many miles did they accumulate?
     The total mileage of each of the "Big Boys" from class 1 was roughly the same - 1,000,000 miles.  4016 had the lowest mileage - 1,016,124.  4006 had the highest mileage - 1,064,625.  Of the second group, 4024 had the highest mileage - 811,956. 
     Where are the surviving Big Boys?
     4004:  Holiday Park, Cheyenne, WY
     4005:  Forney Transportation Museum, Denver, CO
     4012:  Steamtown National Historic Site, Scranton, PA
     4014:  Los Angeles County Fairplex, Pomona, CA
     4017:  National Railroad Museum, Green Bay, WI
     4018:  Age of Steam Railroad Museum, Dallas, TX
     4023:  Kenefick Park, Omaha, NE

     Will a "Big Boy" ever be restored to operating condition?
     This question comes up frequently.  If restoration were to be attempted, it would make most sense to start with the Big Boy that is in the best condition.  At one time, this would have been 4023, currently at Kenefick Park, Omaha, NE.  During the end of their careers both Challenger 3985 and Big Boy 4023 were rebuilt and placed in the Cheyenne UP roundhouse.  However, 4023 was later displayed in Omaha and the weather and environment has taken its toll on 4023.  Currently, 4014, displayed in Pomona, CA has been kept in immaculate condition by the Southern California Chapter of the Railway & Locomotive Historical Society.  Today, it would make most sense to start with this one.
     However, according to many sources, the UP is loathe to run a coal fired locomotive on their road any longer (the 3985 (4-6-6-4) was converted to oil in the late 1980's).  Naturally, the next question one asks is "why not convert a Big Boy to oil?".  This was tried, in fact, back in the 1940's or 1950's on 4005, without success.  It is not feasible to fire a "Big Boy" with oil, du to the nature of the firebox and boiler capacity.
     Steve Lee (head of UP's steam program) has also stated that it wouldn't make much sense for UP to restore a "Big Boy," as there are only two places on the entire system that are large enough to turn a Big Boy, and those place's are only a few miles apart.
 
 

Page last revised - 3/06/02