Athearn Genesis HO 4-6-6-4 Challenger w ESU LokSound, UP #3802, ATHG97239

athg97239 Snd
MSRP $629.98
Normally Available Within 10 Days if Out of Stock

*Please note, these locomotives were originally announced with Tsunami Sound, but have been delivered with ESU LokSound. 
HO Early Challenger 4-6-6-4, CSA-1 Class, with Coal Tender, with ESU LokSound DCC
Union Pacific, Cab #3802

Athearn Item #ATHG97239

This stunning reproduction of the 4-6-6-4 Challenger is the result of a focused determination to accomplish one thing: create the finest operating miniature representation of the prototype available. To say Athearn has succeeded would be an understatement. 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. The Genesis 4-6-6-4 Challenger includes a history book and instruction book for quick reference.


  • Boiler backhead with printed manual controls

  • Individually applied piping, valves, generators, etc.

  • Correctly operating eccentric cranks

  • Adjustable cab windows

  • Headlights and number boards with directional light change

  • Tender light • Genesis Five pole, skewed armature motor with two flywheels

  • Pivoting front and rear engines for negotiating 18" radius curves

  • Current pick-up on all driver and tender wheels

  • 8-pin connector plug between loco and tender


  • All road numbers

    • Spark arrestors

    • Coal and oil tender versions

    • Three different numbering systems: 3700, 3800, 3900

    • Single and twin stack versions

    • Large and small dome versions

    • Early and Late style lettering schemes

    • With coal rack or without coal rack

    • Two steam pipe versions

    • There are five different pilots:

      • Boiler Tube with Widely Spaced Handrails

      • Steel Bars with Narrowly Spaced Handrails

      • Cast

      • Steel Bars with Wide Shield

      • Footboard Pilot


  • Onboard DCC decoder with ESU LokSound

  • Sound, units operate in both DC and DCC

  • Full DCC functions available when operated in DCC mode

  • Engine, whistle, and bell sounds work in DC

  • All functions NMRA compatible in DCC mode

  • Excellent Slow speed control

  • Many functions can be altered via Configuration Value (CV) changes

  • CV chart included in the box

Road Number Specific Details

Union Pacific

  • #3802:

    • Coal Tender w/ Rack

    • CSA-1 Class

    • Large dome version

    • Cast Pilot

The Union Pacific Challengers were a type of simple articulated 4-6-6-4 steam locomotive built by American Locomotive Company for the Union Pacific Railroad. 105 of these locomotives were built between 1936 and 1943. The Challengers were nearly 122 ft (37 m) long and weighed 284,800 kg. They operated over most of the Union Pacific system, primarily in freight service, but a few were assigned to passenger trains operating through mountain territory to California and Oregon. The locomotives were built specifically for Union Pacific and much of the experience gained later went into the design of the “Big Boy”.

The name “Challenger” was given to steam locomotives with a 4-6-6-4 wheel arrangement. This means that they have four wheels in the leading pilot truck, which helps guide the locomotive into curves, two sets of six driving wheels, and finally four trailing wheels, which support the rear of the engine and its massive firebox. Each set of six driving wheels is driven by two steam cylinders. In essence, the result is two engines under one boiler. The Union Pacific Railroad sponsored development of this type to meet the need for higher speeds in main-line service. Historically, articulated locomotives had been limited to slow speeds by factors inherent in their design. The technical breakthroughs achieved with the Challenger enabled the carrier to develop the Big Boy with the same speed expectations. Speeds in excess of 60 M.P.H., while unheard-of on other railroads using articulated steam locomotives, became commonplace on the Union Pacific.

The 105 were divided into five orders, which can be put into two groups: the first two orders of “original” also known as “light” Challengers, and the final three of “heavy” Challengers. The “Heavy” Challengers are currently available in stock.

More Information
Manufacturer's Suggested Retail Price 629.98
UPC 797534972391
Scale HO
DCC DCC With Sound
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