Big Boy

 
 

Union Pacific Big Boy

Surely the most famous steam locomotives of all were the Union Pacific’s Big Boys.  “That such a vast steam generating plant could be mounted, not on concrete and clothed in brick, but on a flexible base which rode comfortably at 50 miles per hour … these circumstances will be remarked upon as long as men gather to talk of steam and steel,” wrote the late Trains Magazine editor David P. Morgan.


The Union Pacific—America’s first transcontinental railroad—has always been in the business of hauling heavy trains at speed over long distances, and has always had a need for a fleet of the largest, most modern locomotives.  But in 1940, as the depression eased and with the coming of war, it lacked a locomotive that could both pull on mountain grades, what its existing locomotives could pull on the flat, and sustain speeds over 50 miles per hour.  Vice President Otto Jabelmann’s mechanical staff calculated that it would take an engine with 135,000 lbs. of starting tractive effort to pull 3,600-ton trains, unassisted, up the 65-mile Wasatch grade east from Ogden, Utah—the toughest climb on the Overland Route.  Such an engine would, of course, require a giant boiler and huge grate area (the railroad’s own coal lacked the high heat content of the coal available to the eastern coal-haulers), but these would easily provide the 540,000 lbs. on drivers it needed for adhesion.  To spread the locomotive’s estimated total weight of 762,000 lbs. without excessive axle loading, a 4-8-8-4 was recommended.

 

The resulting 4000-class locomotives were known from the start as the world’s largest.  Before No. 4000 received its final painting, a mechanic at the American Locomotive Company in Schenectady, New York scrawled the words “big boy” in chalk on its huge smokebox door and soon the railroad was using this name to publicize the locomotives.  UP President Arthur E. Stoddard, “Boss of the Big Boys,” called them “the greatest engines I had seen.”   More than the tools of an era, they were a symbol of the finest in transportation.


Twenty-five Big Boys were built in two groups: Nos. 4000–4019, later designated 4884-1, were delivered beginning in September, 1941.  Nos. 4020–4024, designated 4884-2, followed in 1944 to handle the transcontinental traffic boom of late World War II.  Both groups went to work on the Wasatch where, in later years, after millions of miles of service, the railroad increased their rating to 4,450 tons.  Their boilers could evaporate 200 gallons of water per minute, so they needed frequent water stops when hauling heavy trains.  Yet they could be serviced in as little as an hour, and could make 7,000 miles per month.  On test, one recorded 6,290 drawbar horsepower. 


There was one conspicuous difference between the two groups.  As built, the 1941 engines had fin after cooler piping (part of the air brake system) mounted high on the pilot deck.  The 1944 engines arrived with these mounted behind the air pump shield to reduce icing (the UP modified the first engines to follow suit in 1948–52).  There were other, more subtle differences of course.  Alloy steel was used wherever possible in the 4884-1s, but medium-carbon steel was substituted in the 4884-2s, due to wartime restrictions.  As a result, these were heavier — at 772,250 lbs. for the locomotive in working order, and more than 1.2 million lbs. with tender.  Nos. 4020–4024 rank with the C&O’s first Alleghenies as the heaviest steam locomotives ever built.


The Big Boys’ extended proportions made them look big—while other railroads owned locomotives with eight driving axles, none had drive wheels as large as the Big Boys’ 68 inches, nor a four-wheel engine truck out front to guide them into curves at high speeds—and they were big.  With an overall length of nearly 133 feet for engine and tender, they required the Union Pacific to build three new 135-foot turntables, realign several curves for adequate clearance on adjacent tracks, and make other improvements.  The Big Boys’ 300 psi boiler pressure and roller bearings on all axles represented the state-of-the-art.  They ran wonderfully well so there was little need for experimentation.  After World War II, 4005 was converted to oil, but the burner caused uneven heating and leaking, and was soon removed.  In addition, elephant ear smoke-deflectors were mounted on 4019 in 1949, but for only a few runs.  About the same time, however, steel coal boards were added to the tenders to increase coal capacity by four tons (this feature became permanent).


The Big Boys continued in operation for nearly 18 years, and all, of the first group, accumulated more than 1,000,000 miles before retirement.  They worked all their lives in Wyoming, Utah, Colorado, and very occasionally, into Nebraska.  They were well maintained until nearly the end—twenty-three were shopped as late as 1957—and six of them were still active into the early summer of 1959 out of Cheyenne, the Mecca of steam.  Today, eight of them are preserved: No. 4004 in Cheyenne, No. 4005 in Denver, No. 4006 in St. Louis, No. 4012 in Scranton, PA, No. 4014 in Pomona, CA, No. 4017 in Green Bay, No. 4018 in Dallas, and No. 4023 in Omaha.


Fine Art Models


Fine Art Models has built both 4884-1s and 4884-2s, each as built and as modified.  To help us do justice to this project, Bill Kratville of the Union Pacific Museum arranged for us to visit the UP Steam Team in Cheyenne.  This team graciously hosted us as we scanned more than two thousand original india ink-on-linen engineer drawings.  The Union Pacific Historical Society immediately took an interest in our approach, bought our scanner and, today, under the guidance of steam locomotive engineer Bob Krieger, its volunteers continue to scan thousands more drawings.  In addition to these collaborations, Fine Art Models commissioned author (The History of the Union Pacific Railroad in Cheyenne), historian and expert model builder, Robert Darwin, for guidance to assure the absolute accuracy of all details on our Big Boy model.  We are confident that this is the finest steam locomotive model ever built, and will become the benchmark for all future generations of model builders. 


The Big Boy locomotive includes our patented sound system, large twin Pittman motors, ball bearings at all moving points and complete back-head detail with scale gauges.  Every door, hatch or inspection plate that opens on the real locomotive also opens on our model.  The locomotive comes with a black walnut display base and leaded glass case with ballasted track, operating scale signals, and a signed, limited edition lithograph.


References


Bush, John E. and Ehrenberger, James L., Big Boy Portraits, Cheyenne, Wyoming, Challenger Press, 1996 — photos of each of the 25 Big Boys at different stages of their service

 

Darwin, Robert, The History of the Union Pacific Railroad in Cheyenne; Carmel Valley, California, Express Press Limited, 1987 — the finest coffee table book ever written about railroading, including many photos of Big Boys in action

 

Kratville, William W., Big Boy, Omaha, Nebraska, Barnhart Press, 1963 — still the primary source book for information about the design and operating history of the Big Boy

 

Morgan, David P. ed., Steam’s Finest Hour, Milwaukee, Kalmbach Publishing Co., 1959 — photos, statistics, and descriptions of selected modern American steam locomotives


Stagner, Lloyd E., Union Pacific Motive Power in Transition, 1936–1960; David City, Nebraska, South Platte Press, 1993 — Union Pacific management’s perspective of the evolution, operation, and obsolescence of the Big Boy and other late steam locomotive classes

Union Pacific Big Boy - As Built


Scale:                            1:32

Release:                        2000

Limited Edition:              50

Model Size:                   50”L x 5”W x 7”H

Base Type:                   Black Walnut

Base/Case Size:           56”L x 12”Wx 10”H

Availability:                    Sold Out


Union Pacific Big Boy - As Modified


Scale:                            1:32

Release:                        2000

Limited Edition:              50

Model Size:                   50”L x 5”W x 7”H

Base Type:                   Black Walnut

Base/Case Size:           56”L x 12”Wx 10”H

Availability:                    Sold Out


Union Pacific Big Boy - 2nd Edition As Built


Scale:                            1:32

Release:                        2000

Limited Edition:              25

Model Size:                   50”L x 5”W x 7”H

Base Type:                    Black Walnut

Base/Case Size:           56”L x 12”Wx 10”H

Availability:                    Sold Out


Union Pacific Big Boy - 2nd Edition As Modified


Scale:                            1:32

Release:                        2000

Limited Edition:              25

Model Size:                   50”L x 5”W x 7”H

Base Type:                    Black Walnut

Base/Case Size:           56”L x 12”Wx 10”H

Availability:                    Sold Out

Looking for a Big Boy? Please visit the previously owned section of our website.Previously_Owned_Trains.html