Athearn HO G2 SD90MAC-H Phase I w/DCC & Sound UP #8503 ATHG27320 HO Locomotives

Original price was: $359.99.Current price is: $314.99.

Athearn HO G2 SD90MAC-H Phase I w/DCC & Sound UP #8503 ATHG27320 HO Locomotives

“Hey everyone, just a heads up that some links in this video/description are affiliate links. I may earn a small commission if you purchase something through them. Thank you for your support!”

SKU: ITC35736459ITC Category:


The G2 SD90MAC-H Phase I was a relatively short-lived but interesting locomotive in the history of American diesel traction. Here’s a breakdown of its history:


  • Introduced in 1996 by Electro-Motive Diesel (EMD) as a variant of the SD90MAC locomotive.
  • Designed to utilize the new 6,000 horsepower (4,500 kW) 16-cylinder H-engine, a more powerful upgrade over the earlier 710G engine.
  • Distinguished by its “Phase I” cab, characterized by a rounded nose and lower windshield compared to the later Phase II cab.

Production & Usage:

  • Only 22 units were ever built, all for the Union Pacific Railroad (UP).
  • Considered a “pre-production” or “beta” version of the SD90MAC-H, as they faced technical issues with the H-engine in its infancy.
  • Initially delivered with 4,300 hp (3,210 kW) 16-cylinder 710G engines, similar to the SD70MAC’s, due to the H-engine problems.
  • UP planned to re-engine them with the 6,000 hp H-engine when it became fully reliable, but ultimately scrapped all 22 units by 2009 without ever receiving the upgrade.


  • Despite its limited lifespan, the G2 SD90MAC-H Phase I played a valuable role in testing and refining the H-engine technology.
  • It paved the way for the more successful Phase II SD90MAC-H with the improved H-engine and Phase II cab, of which nearly 70 units were built.
  • It remains a unique locomotive in railroad history, with its distinct Phase I cab and short production run, making it a collector’s item for model train enthusiasts.

Additional Information:

  • Sources mentioned the HO G2 SD90MAC-H Phase I model train by Athearn, suggesting their popularity among scale model enthusiasts.
  • Wikipedia and Athearn product descriptions provided further details on the technical specifications and historical context of the locomotive.

I hope this comprehensive overview provides a good understanding of the G2 SD90MAC-H Phase I’s history and significance.

Additional information






DCC and Sound


There are no reviews yet.

Be the first to review “Athearn HO G2 SD90MAC-H Phase I w/DCC & Sound UP #8503 ATHG27320 HO Locomotives”

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.