The Roundhouse Podcast

The Largest Diesel Locomotive Visits Pittsburgh – DDA40X


Union Pacific always had a thing for powerful locomotives.  Big Boy.  Challenger.  GTEL Turbine.  The Centennials continued that tradition by taking two EMD 645E3A prime movers and fitting them onto one locomotive frame.  The result is a 98 ft 5 in behemoth producing 6,600 horsepower!

These locomotives (47 in totoal) were built between 1969 and 1971.  The DDA40X served as an experimental testbed for manufacturer EMD and remained in service until 1986.  Thirteen survive in preservation, and this one belongs to the Museum of Transportation in St. Louis, MO.  #6944 was recently repainted by Norfolk Southern, and the locomotive is being transported back to the museum.


Thanks to the AltoonaWorks Facebook page, I received notification it was finally heading west today on train 11A.  I raced to Homestead, which features an ex-Pennsylvania Railroad station that has been wonderfully restored.  After catching the TOFC train photographed above, 11A appeared.



You can see from the photo below that I wasn’t the only one out today to catch this.


I’m glad I saw it heading back home today.  It is a very impressive machine.

5 thoughts on “The Largest Diesel Locomotive Visits Pittsburgh – DDA40X

  1. Greg Stewart

    Beautiful Locomotive-impressive
    The older trains,even the diesels are the best
    I will always love the real and toy trains-thisshould be a part of every childhood

  2. Steve Helfrich

    Does anyone know when it will be arriving back in to St. Louis at the museum? I’ve heard it closed for a private Union Pacific party tomorrow (Sunday Jun 7, 2015) and I’m assuming it’s arrival is why. Any help would be appreciated.

  3. Dwight miller

    They are even more impressive when you see one running 70 mph with the UP business train behind her!

  4. john doe

    It has been in the stl area for a few days now. As of this morning when i got off work, it still hasnt been delivered to the up which will take it to the museum.

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