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Athearn Genesis HO scale Canadian National GP9 diesel locomotives

Read this product review from Model Railroader magazine
Athearn HO scale Canadian National GP9
Athearn HO scale CN GP9 diesel
Athearn HO scale Canadian National GP9
Our review sample included a SoundTraxx Tsunami2 decoder mounted above the Athearn Genesis mechanism. The model also features all-wheel drive and pickup.
Athearn HO scale Canadian National GP9
Both of our CN review samples feature roadname- and roadnumber-specfic details and accurate paint schemes.
Superdetailed Electro-Motive GP9 diesel locomotives return to the Athearn Genesis series in several new road names. A previous release was reviewed in the December 2011 issue. This upgraded release is available with a SoundTraxx Tsunami2 dual-mode decoder that operates on Digital Command Control (DCC) and direct-current (DC) layouts.

Successor to the 1,500 hp GP7, the 1,750 hp four-axle GP9 was one of EMD’s best-selling first-generation diesels with more than 4,000 produced from 1954 to 1963. Canadian National rostered 349 GP9s with some rebuilt versions serving into the 1990s.

The Athearn GP9 is within scale inches of a drawing in Model Railroader Cyclopedia: Vol. 2, Diesel Locomotives (Kalmbach Publishing Co., out of print).

Our review samples are detailed and decorated for CN nos. 4409 and 4422 as they appeared from 1955 into the 1960s. Both locomotives are correctly set up to run long-hood forward.

In addition to well-defined molded details, like louvers and engine-access doors, the model is loaded with separate roadnumber-specific detail, including bell placement and exhaust stacks, as shown on the next page.
The CN paint scheme matches prototype photos, including lettering and herald placement. There’s sharp color separation between all the striping.
The model features the same reliable Genesis mechanism, shown below, as the earlier release. On our DCC sample, the decoder board is mounted above the dual-flywheel equipped motor.

Operation. The model’s speed tests in DC and DCC are shown in the charts above. The prototype could be geared for top speeds ranging from 55 to 89 mph. For DCC users, the model’s top speed and the speed curve can be adjusted with configuration variables (CVs).

Even though the locomotive doesn’t include a CurrentKeeper capacitor circuit, its all-wheel drive kept the headlights, motor, and sound steady.

The Tsunami2 decoder’s factory-default sound settings include the correct Nathan K3L air horn. In addition to the long horn, short horn, and bell effects, other user-triggered functions include dimmable headlights and coupler crash effects. There’s also function button controlled manual notching, but I prefer the Tsunami2’s enhanced Digital Dynamic Exhaust (DDE) feature.

After a quick setup, the decoder uses back-electromotive force to automatically set the engine rpm sound to the correct notch per the load. For example, when going up a grade, the engine sounds notch up. When going downgrade, the engine rpm level decreases.

The Tsunami2 features three programmable braking rates. I set the independent brake, used when the locomotive is running light, for relatively quick stops. I set the train brake, used when the locomotive is hauling cars, for a slightly longer braking time. I also set up the dynamic braking rate, which will slow, but not stop, the train when the dynamic brake effect is engaged (F4).

In addition to the printed manual included with the model, an extensive, user-friendly guide is also available as a free download at

In DC the engine sounds increase or decrease with the throttle. The headlights are directional. More effects can be triggered with an analog sound controller, such as the MRC Tech 6.

Prototype-specific details and Tsunami2 sound makes these Geeps standout models of first generation diesel power.


Facts & features

Price: $299.98 (DCC sound), $209.98
(DC no sound)
Athearn Trains
1600 Forbes Way, Suite 120
Long Beach, CA 90810
Era: 1954 to present, (1955 through 1960s as detailed and decorated)
Road names (multiple road numbers): Canadian National, Seaboard Air Line, Southern Pacific “black widow,”
Union Pacific
New paint schemes announced: Canadian Pacific, Central Vermont, Grand Trunk Western, Great Northern, Southern Pacific (scarlet and gray in SP, Texas & New Orleans, and Commute versions)

  • All-wheel drive and electrical pickup
  • 21-pin DCC socket (DC version)
  • Correct scale 40"- diameter metal wheels in gauge
  • Die-cast metal frame
  • Five-pole skew-wound motor with dual brass flywheels
  • Light-emitting diode (LED) headlights
  • McHenry plastic scale knuckle couplers mounted at correct height
  • Minimum radius: 18"
  • SoundTraxx Tsunami2 dual-mode decoder (DCC version)
  • Weight: 11.3 ounces 

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Two great beginner layouts.

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