PROTOTYPE SPECIFIC INFORMATION

The Union Pacific’s Overland Route, the eastern portion of the Transcontinental Railroad, was built west of Omaha, across Nebraska and Wyoming, and on into Utah. The steepest grade was the eastbound climb on the Echo Canyon line through the Wasatch Mountains just east of Ogden, Utah. Forty 4-6-6-4 Challenger locomotives were acquired in 1936 and 1937 to move fast freight over the grades in Utah and Wyoming. They were rated at 4,290 tons across Wyoming, but were limited to 3,100 tons eastbound through Echo Canyon.

Union Pacific wanted something that could make the same speeds as the Challengers but could carry the entire 4,290-ton train over the Wasatch Mountains without a helper. The easiest solution was to scale up the successful Challenger design by adding another pair of drivers to each half of the locomotive, thus making a 4-8-8-4.

In 1941, UP placed an order for 20 4-8-8-4’s, numbered 4000 through 4019, with the American Locomotive Works. Each engine cost $265,174. According to legend, an unidentified machinist at the ALCO plant is responsible for the name “Big Boy”, having scrawled the name in chalk on a partially completed locomotive.

The Big Boys were exactly what the railroad wanted. They were coal burners with 68-inch drivers, 135,375 pounds of tractive effort and 6,000 horsepower. They started service on the line from Ogden to Green River, Wyoming and their operating range soon increased to cover the line all the way to Cheyenne.

4-8-8-4 LOCOMOTIVE FEATURES:

• Boiler backhead with full details and printed gauges
• Individually applied piping, valves, generators, etc.
• Operating eccentric cranks on both sides operationg in correct direction
• Headlights with directional light change
• See-through running boards
• See-through cab windows
• 5-pole skew wound motor, precision machined flywheels, and multi-link drivetrain
• Body-mounted McHenry operating scale knuckle couplers
• Fully-assembled and ready-to-run
• Heavy die-cast frame for greater traction and more pulling power
• Scaled from prototype resources including drawings, field measurements, photographs, and more
• Accurately-painted and –printed paint schemes
• Bidirectional constant LED lighting so headlight brightness remains constant
• Minimum radius: 11”

SOUND-EQUIPPED MODELS ALSO FEATURE

• Onboard DCC decoder with SoundTraxx Tsunami2 sound
• Sound units operate in both DC and DCC
• Full DCC functions available when operated in DCC mode
• Chuff, whistle, and bell sounds work in DC
• All functions NMRA compatible in DCC mode
• Precision slow speed control
• Program a multiple unit (MU) lashup with lead unit only horn, bell, and lights
• Many functions can be altered via Configuration Value (CV) changes
• CV chart included in the box

PRIMED FOR GRIME MODELS FEATURE

• Duplicated look and feel of “In Service” equipment
• Faded base colors matched to the prototype
• Perfect starting point for adding grime and rust

LEGENDARY LIVERIES

What are Legendary Liveries? An Athearn exclusive, they are the ultimate answer to “What if?” Featuring some of the most popular railroad paint schemes of all time, these models are perfect for collecting, protofreelancing, or just plain fun! Whether company proposed paint schemes, canceled locomotive orders, or alternate takes on history, Legendary Liveries are fun and unique additions to any roster. Enjoy these items, and answer the ultimate railroad question of: “What if?”

Santa Fe

With their stable performance at speed and ability to handle large trains, Santa Fe found the 4-8-8-4 concept to be appealing. They took delivery of their 6000 class in 1944 to help handle wartime traffic. ATSF had experimented with compound articulated locomotives in the 1910s, but they were never entirely successful. Buying UP’s design “off-the-shelf” from ALCO was the logical choice, then.*

*Alternate history- some facets have been massaged

ATSF FEATURES:

• Oil burner, cooling pipes, black firebox and smokebox sides

Looking for more Athearn 4-8-8-4 Big Boy Steam Locomotives? Click here!