Description
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 Big Boy enabled the carrier to develop a newer, improved Challenger that met their speed expectations.
Though originally intended for freight service, many Challengers were used in passenger service.
In the spring of 1941 UP locomotive designers began working on a locomotive to team up with the new 4-8-8-4 Big Boy's then under construction at Alco. The Big Boy's were designed to pull heavy freights up the Wasatch Range in Utah to the division point at Green River, WY. What was needed was a locomotive to take over at that point that could speed the freights eastward across the Wyoming Division. Building on their experience with the original CSA 4-6-6-4 Challengers UP and Alco's designers developed a newer and better Challenger type locomotive. The result was a group of 65 4-6-6-4 Challenger built in three separate groups during World War II.
ROAD NUMBER SPECIFIC FEATURES:
#3985
Modern Excursion version
Oil Burner
Era 1980s - 2000s
#3933
Coal Burner
Dual smoke stack
Tender bunker coal extensions
Era 1940s - 1959
#3967
Coal Burner
Dual smoke stack
Smoke Lifters
Era 1940s - 1959
#3997
Coal Burner
Dual smoke stack
Tender bunker coal extensions
Era 1940s - 1959
UP painted several of their Challengers in their two-tone grey paint scheme for passenger service. They also added smoke lifters and converted many to oil burners as well.
ROAD NUMBER SPECIFIC FEATURES:
#3976
Two-tone grey with yellow lettering and striping
Oil burner
Dual smoke stack
Era: Late 1940s - Mid-1950s
FEATURES:
DCC-ready features Quick Plug plug-and-play technology
Scaled from prototype resources including drawings, field measurements, photographs, and more
Accurately-painted and -printed paint schemes
Full cab interior with boiler backhead with printed gauges
Individually applied piping, valves, generators, etc.
Operating eccentric cranks on both sides operating in correct direction
Headlights and indicator number boxes (number boards) with directional light change
Five pole, skewed armature motor with flywheel for smooth operation
Pivoting front and rear engines for negotiating 11" radius curves
See-through running boards
See-through cab windows
McHenry scale knuckle couplers
LED Lighting for realistic appearance
Fully-assembled and ready-to-run
Heavy die-cast frame for greater traction and more pulling power
Minimum recommended radius: 15"
Though originally intended for freight service, many Challengers were used in passenger service.
In the spring of 1941 UP locomotive designers began working on a locomotive to team up with the new 4-8-8-4 Big Boy's then under construction at Alco. The Big Boy's were designed to pull heavy freights up the Wasatch Range in Utah to the division point at Green River, WY. What was needed was a locomotive to take over at that point that could speed the freights eastward across the Wyoming Division. Building on their experience with the original CSA 4-6-6-4 Challengers UP and Alco's designers developed a newer and better Challenger type locomotive. The result was a group of 65 4-6-6-4 Challenger built in three separate groups during World War II.
ROAD NUMBER SPECIFIC FEATURES:
#3985
Modern Excursion version
Oil Burner
Era 1980s - 2000s
#3933
Coal Burner
Dual smoke stack
Tender bunker coal extensions
Era 1940s - 1959
#3967
Coal Burner
Dual smoke stack
Smoke Lifters
Era 1940s - 1959
#3997
Coal Burner
Dual smoke stack
Tender bunker coal extensions
Era 1940s - 1959
UP painted several of their Challengers in their two-tone grey paint scheme for passenger service. They also added smoke lifters and converted many to oil burners as well.
ROAD NUMBER SPECIFIC FEATURES:
#3976
Two-tone grey with yellow lettering and striping
Oil burner
Dual smoke stack
Era: Late 1940s - Mid-1950s
FEATURES:
DCC-ready features Quick Plug plug-and-play technology
Scaled from prototype resources including drawings, field measurements, photographs, and more
Accurately-painted and -printed paint schemes
Full cab interior with boiler backhead with printed gauges
Individually applied piping, valves, generators, etc.
Operating eccentric cranks on both sides operating in correct direction
Headlights and indicator number boxes (number boards) with directional light change
Five pole, skewed armature motor with flywheel for smooth operation
Pivoting front and rear engines for negotiating 11" radius curves
See-through running boards
See-through cab windows
McHenry scale knuckle couplers
LED Lighting for realistic appearance
Fully-assembled and ready-to-run
Heavy die-cast frame for greater traction and more pulling power
Minimum recommended radius: 15"
