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Summary: Union Pacific 4-8-8-4 Big Boy Locomotive...
|Print of the Union, Pacific, 4-8-8-4, Big, Boy, Locomotive ... Historic Artwork.|
| Continued from above... D (24 x 36 inches) |
Creator: Alco, Union Pacific
Historical Information: After the introduction of their first Challenger-type (4-6-6-4) locomotives in 1936, the Union Pacific Railroad needed a locomotive with greater sustained tractive effort and horsepower to eliminate doubleheading and helper operations on the Wasatch grades in eastern Utah and western Wyoming.
In collaboration with the American Locomotive Company, the UP's design team, headed by Otto Jabelmann, re-examined the original Challengers designed by A.H. Fetters. They found that by increasing the firebox to approximately 235" x 96" (about 155 square feet), lengthening the boiler, adding two driving wheels and reducing the size of the driving wheels from 69" to 68", the desired locomotive was possible. The largest steam engine in the world had been created.
Click on a photo below to enlarge. The images above (approximately 20 rare and original steam train photos)
A Big Boy could generate a maximum of 6,290 drawbar horsepower. The Big Boys rendered important service in the Second World War, especially since they proved so easy to fire that even a novice could do a fair job. During the war, after German agents filed reports that the Americans had giant steam engines that were moving huge trains full of vital war material over steep mountain grades at high speed, their reports were dismissed as "impossible". Their performance in moving a huge volume of war material throughout WWII was repeatedly cited and the Big Boys are generally acclaimed as having made a huge contribution to the war effort.
The Big Boy is one of the best represented and preserved model of steam locomotive in the United States, due to its mythical reputation and late survival in service to 1959. Eight of the 25 made still exist.
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