AZL Direct


| April 25, 2012 | 0 Comments

ChallengerAbout the Challenger:

Built between 1936 and 1943, the Challengers were nearly 122 feet long and weighed more than one million pounds. Articulated like their big brother, the Union Pacific Big Boy, the Challengers had a 4-6-6-4 wheel arrangement. 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 105 locomotives were built specifically by ALCO for Union Pacific having drawn on much of the Big Boy’s experience.

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 driving wheels has its own steam cylinder. In essence, the result is two engines under one boiler.


AZL Model Details:

  • 10mm Faulhauber motor
  • LED light on the tender
  • Articulated brass body
  • Cab interior
  • Prototype specific detailing
  • This is a limited edition release


Model Photos:


AZL Challenger:

AZL #Single | SetRoad NameRoad Number
17052-1Single | Gray GooseUP3977
17052-2Single | Gray GooseUP3981
17051-1Set | Coal Tender | Red Caboose | 12 ReefersUP3942
17051-2Set | Coal Tender | Red Caboose | 12 ReefersUP3950
17053-1Set | Coal Tender | Yellow Caboose | 12 ReefersUP3960
17053-2Set | Coal Tender | Yellow Caboose | 12 ReefersUP3968
17053 Set | Oil Tender | Yellow Caboose | 12 ReefersUP3985


Additional Manufacturer Notes:

Prototype background material from Wikipedia

Category: Locomotives