HO 4-8-8-4 Big Boy w/DCC & Sound, Black/Unlet #2

Key Features

  • Boiler backhead with printed gauges
  • Individually applied piping, valves, generators, etc.
  • Operating eccentric cranks on both sides operating in correct direction
  • Adjustable cab windows
  • Headlights and number boards with directional light change
  • Five pole, skewed armature motor with dual flywheels for smooth operation
  • Pivoting front and rear engines for negotiating 22" radius curves
  • See-through running boards
  • Smoke unit ready with no soldering required

Detailed Information

The Genesis 4-8-8-4 Big Boy, like the 4-6-6-4 Challenger before it, is the culmination of design andtooling, integrating the latest innovations in electronic technology. The Big Boy model has been developed from the outset as the finest operating miniature representation of the prototype available.

Giving life to all the details are authentic sounds that are channeled through a factory installed DCC and soundboard with speakers. The DCC decoder automatically senses what type of power supply is in use (conventional DC or NMRA compliant DCC) and adapts its functions. The modeler doesn’t have to do a thing.

Functions and sounds available to DCC users include:
Water injector
Air release
Blower hiss
Fire box door
Lighting direction
Brake squeal
Conductor’s voice
Sand release
Cylinder cock/flange squeal

A handheld wireless controller is included for use with conventional DC power supplies. With it, modelers can control six sound functions as well as speed and direction.

The Genesis 4-8-8-4 Big Boy includes a history book and instruction book for quick reference.


The Union Pacific's Overland Route, the eastern portion of the Transcontinental Railroad, was built west from Omaha, across Nebraska and Wyoming, and on into Utah. The steepest grade was the eastbound climb on the Echo Canyon line through the Wahsatch 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 Wahsatch 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 twenty 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. Traffic during WWII resulted in 5 more Big Boys, numbered 4020 through 4024, being built in 1944. These versions were slightly heavier than the original order due to wartime materials restrictions.

Despite the influx of diesel locomotives following WWII, the Big Boys and Challengers remained the prime power on the Overland Route. They also saw service as helpers, leading gas turbines and diesels over Sherman Hill. They remained active through the 1950's and weren't retired until the early
1960's. By then the first twenty units had been run well over one million miles. Eight of the twenty-five Big Boys have been preserved in the following locations:
#4004 in Cheyenne
#4005 in Denver
#4006 in St. Louis
#4012 in Scranton
#4014 in Pamona
#4017 in Green Bay
#4018 in Dallas
#4023 in Omaha


DCC: Equipped
SOUND: Equipped
RTR/KIT: Ready to Run



HO 4-8-8-4 Big Boy w/DCC & Sound, Black/Unlet #2



Out of Stock

This product is discontinued.