PROTOTYPE SPECIFIC INFORMATION

ALCO constructed the first 4-6-6-4 locomotives in the world, numbered 3900 to 3914, for the Union Pacific Railroad in 1936. These huge engines were named the Challenger Simple Articulated, or CSA-1, class. The railroad received 25 near copies, classified as CSA-2, the following year.

Unlike compound Mallet engines that crawled along with drag freights, the Challengers had two sets of high- pressure cylinders and could safely reach passenger train speeds. The mammoth locomotives also had a heavy-duty starting tractive effort of 97,400 pounds.

Originally constructed to haul fast freight up the famous Wahsatch grade, the CSA-1 and -2 Challengers would hold a variety of assignments over their long careers- including passenger service. Depending upon their operating territory, they burned either coal or oil, and some locos were converted back-and-forth several times.

STEAM LOCOMOTIVE FEATURES:

• Illuminated number boards and headlights

• Headlight turns off in reverse

• Illuminated directional back-up light in the tender

• Correctly operating eccentric cranks

• Adjustable top cab vent and cab windows

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

• Current pick-up on all driver and wheels

• Boiler backhead with full details and printed gauges

• Synchronized chuff, whistle, bell, blow-down, air compressor, dyno and pop-off valve sounds

• User-controlled whistle, short whistle, bell, squeal, coupler crash, injector, water stop and light dimmer

• Individually-applied detail parts, including brass-painted bell and whistle, piping, valves, generator, steps, air pump, air tanks, reverser and coupler lift bar

• Front coupler pocket can be inserted to mount operating coupler

• Dual cube speakers for great sound quality

• Lighted firebox flicker effect with see-through firebox door

• Upgraded headlight lighting with brighter LED

• Improved loco-to-tender connection harness for increased durability and serviceability

• Minimum recommended radius: 22”

SOUND-EQUIPPED MODELS ALSO FEATURE

• Tender-mounted DCC decoder with SoundTraxx Tsunami2 sound

• Dual cube speakers for optimal sound quality

• 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

• 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

Union Pacific

ROAD NUMBER SPECIFIC FEATURES:

• #3820 Class CSA-2, Worthington feedwater heater, large sand dome, covered vertical bar pilot, walkway “hump”, no steam pipe to front cylinders, blackened metal side rods, satin paint finish, oil burner. Era 1940s+

• #3823 Class CSA-2, Elesco feedwater heater, large sand dome, covered vertical bar pilot, walkway “hump”, no steam pipe to front cylinders, blackened metal side rods, satin paint finish, oil burner. Era 1940s+

• #3907 Class CSA-1, Worthington feedwater heater, standard sand dome, boiler-tube pilot with wide handrails, no walkway “hump”, steam pipe to front cylinders, blackened metal side rods, satin paint finish, coal burners. Era 1936+

• #3911 Class CSA-1, Worthington feedwater heater, standard sand dome, boiler-tube pilot with wide handrails, no walkway “hump”, steam pipe to front cylinders, blackened metal side rods, satin paint finish, coal burners. Era 1936+

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