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A review of Athearn Ready to Roll GP40X



An EMD GP40X is a 4-axle diesel locomotive built by General Motors Electro-Motive Division between 1977 and 1978. Power for this unit was provided by a turbocharged 16-cylinder EMD 645F (derivative of the EMD 645 series engine) which could produce 3,500 horsepower (2,600 kilowatts). 23 examples of this locomotive were built for North American railroads. This unit was a pre-production version meant to test technologies later incorporated into EMD's 50-series locomotives EMD SD50 and EMD GP50. Half the GP40X were delivered with an experimental HT-B truck design that were not used on the EMD GP50.

The designation GP40X was also given to an experimental EMD GP40 built on an EMD GP35 frame in May 1965. Only one example of this locomotive was ever produced, the EMD 433A, a 3000hp model predecessor to the GP40 series. The 1965 EMD 433A has very little in common with the 1977 GP40X other than flared radiators and a 645-series prime mover.






Out of the box it was impressive first starting with the new box design for the RTR items from Athearn.  Gone are the flimsy boxes with a nice strong and sturdy box without the foam cushion.

The engine was impressive as it has the AC on and all the piping on the roof installed. The engine also has a working strobe light!  The only a small number of add-ons are need to make this a nicely detailed engine.



On The Track:

On the track the performance was very nice with a slow start up speed and smooth drive.


DCC System:

The plug and play DCC makes it easy to install a decoder.  The only issue was the strobe light is attached to the circuit board.  But with a six function decoder it only takes about 10 minutes to modify the light to work independently from the head lights.




This new tooling is a vast improvement for Athearn and sure to be a hit.  This engine gets a 9 out of 10.


EMD GP40X. (2007, January 11). In Wikipedia, The Free Encyclopedia. Retrieved 21:54, February 6, 2007, from



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