N 4-6-6-4 w/DCC & Sound Coal Tender, NP #5148

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Detailed Information


  • Brand new locomotive and tender tooling
  • NP and SP&S road specific details
    • Cast pilot with fold-down coupler
    • Enclosed cab with side entry doors, fixed roof hatches and simulated diaphragm
    • Smokebox-mounted air pumps
    • Two sizes of wheels in the trailing truck
    • NP-style expansion link, which supports much of the valve gear
    • NP specific welded coal tender
    • SP&S specific welded oil tender
  • Fully-assembled and ready-to-run
  • Boiler backhead with printed manual controls
  • Individually applied piping, valves, generators, etc.
  • Correctly operating eccentric cranks
  • Headlights and number boards with directional light change
  • Tender light
  • Genesis five pole, skewed armature can motor with flywheels
  • Pivoting front and rear engines for negotiating 11” radius curves
  • Current pick-up on all driver and tender wheels
  • 8-pin connector plug between loco and tender
  • McHenry operating knuckle couplers installled
  • Minimum radius: 11”
  • Recommended radius: 15”


  • Onboard DCC decoder with SoundTraxx Tsunami sound
  • 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


The Northern Pacific ordered 21 “Challengers” from the American Locomotive Company in 1936 and took delivery of them during 1936 and 1937. These 4-6-6-4s were designated Class Z-6 and were assigned road numbers 5100 through 5120. They had four 23 x 32 cylinders, 69” drivers, a 250 psi boiler pressure, exerted 104,500 lbs of tractive effort and weighed 624,500 pounds. In 1941, another six “Challengers” came from ALCO. These were designated Class Z-7 and they carried road numbers 5121 through 5126. They had four 23 x 32 cylinders, 70” drivers, a 260 psi boiler pressure, exerted 107,000 lbs of tractive effort and weighed 644,000 pounds. The last steam locomotives bought by the Northern Pacific were the 20 “Challengers” it purchased from ALCO during 1943 and 1944. This group designated Class Z-8 was assigned road numbers 5130 through 5149. The Class Z-8 locomotives were virtually identical those of Class Z-7. Two oil-burning Z-8s were also delivered to the SP&S.


This class was essentially identical to the 1941 Z-7s these locomotives were produced under a wartime mandate to replace certain high-strength steel components with similar items produced with more common and heavier steel. Even so, the NP’s diagrams show no difference in the adhesion weight and just a 1,000 lb difference on engine weight.

The firebox heating surface included 136 sq ft in eight circulators. These also featured a bearing design that permitted smooth riding at higher speeds.

There are no surviving Northern Pacific “Challengers”.


DCC: Equipped
COUPLER STYLE: McHenry knuckle
ERA: 1940 - 1955
MIN. RADIUS: 15" recommended
Minimum Age Recommendation: 14 years
Is Assembly Required: No

N 4-6-6-4 w/DCC & Sound Coal Tender, NP #5148



Out of Stock

This product is discontinued.
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