Athearn Trains HO scale GE ES44AC GEVO diesel locomotive

A mainstay of today’s main lines, the General Electric Evolution Series (GEVO) ES44AC is now available as part of the Athearn Genesis line of superdetailed HO scale locomotives. We tested a BNSF and a Union Pacific version. Both models feature prototype-specific detailing and a SoundTraxx Digital Command Control (DCC) sound decoder.

Prototype. The General Electric ES44AC (Evolution Series 4,400 hp with alternating-current traction motors)
entered production in 2005. Like its main competitor, the Electro-Motive Diesel SD70ACe, the GE ES44AC meets the United States Environmental Protection Agency’s strict Tier II emissions regulations. The heart of the locomotive is its 4,400 hp GEVO-12 diesel engine that produces as much horsepower as the 16-cylinder diesel engine in the GEVO’s predecessor, the AC4400CW. The GEVO engine also has greater fuel economy and lower emissions.

Both BNSF and Union Pacific were early adopters of the GEVO locomotives and rostered pre-production units starting in 2003. Both roads now have ES44 series fleets that number well over 1,000 units. Part of the BNSF’s fleet includes versions with direct-current traction motors (ES44DCs) and new ES44C4 units that have four alternating-current traction motors rather the six of a standard ES44AC.

The BNSF and UP models feature prototype-specific detailing

The model. The November 2004 Model Railroader features prototype drawings of a pre-production ES44AC. Most of the dimensions of the pre-production version are the same as production ES44ACs, including the length (73′-2″) over coupler pulling faces and 42″ wheels. However, the pre-production versions were slightly narrower (9′-11″) and shorter (15′-5″) than production versions. The Athearn model has the correct dimensions for a production ES44AC including the 10′-3″ width and 16′-0″ height.

Both versions have the correct sand filler-rear headlight configuration

The plastic body shell on the Athearn model features accurately placed engine access doors, grills, and other molded detail. The BNSF and UP versions feature prototypical placement of the rear headlight and rear sand box filler. The placement of the global positioning satellite (GPS) dome and antenna is correct for each road name. The BNSF version also includes a window on the nose door.

Separate details abound on the model, including piping along the fuel tank and see-through grills over the dynamic brake fans. The scale-profile handrails and m.u. hoses are made of flexible acetal plastic that resist breaking. Athearn even modeled the rearview mirror on the engineer’s side of the cab.

The cab interior includes instrument panels and three crew seats. Crew figures aren’t included, so the modeler will have to add his own. Exploded-view diagrams and disassembly instructions are included with the model.

The paint on the BNSF and UP samples matches prototype photos. All the warning decals and other stencils are correctly placed.

The models mechanism is housed in the center of the frame. An extra metal weight along with all-wheel drive contribute to the locomotives pulling power.

Mechanism. After placing the locomotive upside down in a foam cradle, I removed the coupler boxes and two additional Philips-head screws on each side of the locomotive’s fuel tank. I then carefully separated the frame from the locomotive shell. The model’s mechanism is almost identical to that of the Athearn Genesis SD70ACe.

The motor and flywheels sit in the center of the die-cast metal chassis. Two shafts transfer power to gearboxes over each truck. There’s an additional die-cast metal weight over the rear truck.

The SoundTraxx Tsunami DCC decoder is mounted on a plastic base that fits over the motor. A speaker rests vertically in its housing just behind the cab.

Performance. The model easily negotiated the no. 6 turnouts on our layout. I also ran the model around an 18″ radius curve, but it looks a lot better on curves with a 22″ or greater radius.

As you can see in the chart on the right, the model has impressive pulling power on level track. The big diesel also hauled 15 cars up a 3-percent grade without slipping or stalling.

On our direct-current (DC) test track, the ES44AC required 7 volts (V) to fire up the sound system and 8V to start moving. The model’s movement had a slight stutter at speeds under 10 scale mph. From 9V to 12V the model accelerated smoothly to a top speed of 95 mph. The prototype has a 75 mph top speed.

The most prominent sound in DC is the rumble of the engine. I’ve heard GEVOs at trackside, and I think the
engine sounds of the Athearn model are spot-on. In DC the rpm sounds increased as I advanced the throttle.

A bell turned on at speeds under 10 scale mph and the horn blew a grade-crossing signal whenever I quickly advanced the throttle. The sound cut out momentarily whenever I changed the locomotive’s direction, which I found a bit annoying.

As shown in the charts, the model had smoother performance on our DCC test track, including a more prototypical 75 mph top speed. Running the model on a DCC system also allowed me to use the SoundTraxx decoder’s programming capabilities to their fullest potential, including fine-tuning the locomotive’s motor performance and advance consisting two locomotives.

Depending on the DCC speed step, our BNSF sample ran 3 to 4 mph faster than our UP sample. One thing I don’t like about SoundTraxx decoders is they don’t support configuration variables (CVs) 5 (top voltage) and 6 (mid voltage). These two CVs are useful for quick and easy speed matching. Instead I had to program all 28 speed steps of a custom speed table for the UP sample so that I could speed match the two locomotives. The pair of GEVOs then ran smoothly together when I advance consisted them with our MRC DCC system.

User-triggered functions in DCC include the bell, long and short horn blast, and dynamic brake fans. I could also activate the headlights and ditchlights independently. The diesel rpm can be set to increase automatically according to the number of DCC speed steps, or the engine effect can be set for manual notching where the diesel rpm is controlled independently from the locomotive speed.

A listing of the decoder’s suppor3ted CVs are included with the model’s instruction booklet. A more extensive user’s guide is available as a free download at www.athearn.com/DCC.

The ES44AC continues Athearn’s tradition of meticulous detailing found in its Genesis-series locomotives.

Price: $299.98 (DCC sound), $199.98 (DC no sound)

Manufacturer
Athearn Trains
1600 Forbes Way, Ste. 120
Long Beach, CA 90810
www.athearn.com

Era: 2005 to present

Road names (multiple road numbers): BNSF Ry., Canadian Pacific, Union Pacific

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