Athearn Genesis - HO Scale - 4-6-6-4 Challenger DCC Ready - Union Pacific (UP) - #3710 - Black/Gray Smoke Box (SKU 141-97294)
Available On: January 1, 2018
UNION PACIFIC PROTOTYPE HISTORY:
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.
UP Key Features
Boiler backhead with printed manual controls
Individually applied piping, valves, generators, etc.
Correctly operating eccentric cranks
Adjustable cab roof vent
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
ROAD NUMBER SPECIFIC FEATURES:
ORIGINAL CHALLENGER SPOTTING FEATURES:
All road numbers
Spark arrestors
Coal and oil tender versions
Three different numbering series: 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
#3710:
Coal Tender w/ Rack
Double Smoke Stack
CSA-1 Class
Cast Pilot