Print
Category: Prototype Reference for Modelers
Hits: 282

Phases of Union Pacific SD70Ms

Telling the difference between UP SD70M phases, in short.

In the quest to find myself a UP SD70M to model, I've started mapping out the differences and "phases" of UP SD70M's. This list will be fairly incomplete & quite simple for now. I hope to get some input to make the list way more specific.

I've chosen the following two units. First up is UP 4847, this unit was built in 12/2002, and has a Phase II Cab, and Tier I (referred to here as a flare) radiator. Here's where the first difference came of light. I then chose UP 4733, this unit was built in 01/2002, and has a Phase I cab, and a Tier I radiator [Ed. similar to #4718 above]. I chose to model two so far, just to have two different styles.

There's a select few SD70M's with flares that have the Phase II cab, squished in the roster in places. These units have two (2) large radiator panels per side. Later units Have four (4) Panels per side, starting at UP #5126 (#5125 has a Phase I cab). Here's a picture of #5128. - A majority of all Phase I cab, flare SD70M's have two (2) large radiator sections per side.

Three (3) SD70M's without flares have the original Building America paint, and the flags to these 3 are unique. This paint scheme is unique to #4526, #4527, & #4528. Microscale makes a decal sheet for these units, 87-1145 for HO, and 60-1145 for N. Athearn also had these units in their Genesis line of SD70M's.

UP 3978 looks to have started as a straight stripe, then they added the lightning bolt, and ended up with a low striped unit. One off, only one that exists. This is a former SP unit. Notice how low the winged logo is on the nose. Here's a picture.

UP 3997 is similar to the previous unit, however the red stripe ends at the forward windows, not the nose. Also a former SP unit. Again, notice how low the winged logo is on the nose. I have not yet established what the "common place" is for these. Here's a picture.

In addition to paint and body differences noted here, visit EMD SD70 Series Water Sight Glass for an important change early in EMD's production of the SD70 series.

Number range breakdown:

UP 2001-2002 Phase I cab, Special Olympic Torch Relay paint, renumbered from 4690-91.

UP 3778 Phase I cab, renumbered from #4141 to make way to George Bush SD70ACe.

UP 3779-3873 Phase I cab, flare with 4 panels, full Building America scheme with wings & flags.

UP 3874-3927 Phase I cab, flare with 2 panels, full Building America scheme with wings & flags.

UP 3928-3970 Phase I cab, flare with 4 panels, full Building America scheme with wings & flags.

UP 3971-3973 Phase II cab, flare with 4 panels, full Building America scheme with wings & flags.

UP 3974-3977 Phase I cab, some in full Building America scheme with wings & flags. These are Fmr SP units. UP 3978 Phase I cab, nose wings, low stripe one off unit, Fmr SP unit.

UP 3979-3996 Phase I cab, some in full Building America scheme with wings & flags. These are Fmr SP units. UP 3997 Phase I cab, nose wings, low stripe one off unit, Fmr SP unit.

UP 3998-3999 Phase I cab, some in full Building America scheme with wings & flags. These are Fmr SP units.

UP 4000-4525 Phase I cab, nose wings, #4141 renumbered to make way for SD70ACe (see above).

UP 4526-4528 Phase I cab, full Building America scheme with wings & flags.

UP 4529-4634 Phase I cab, nose wings.

UP 4635-4639 Phase I cab, some in full Building America scheme with wings & flags.

UP 4640-4689 Phase I cab, nose wings.

UP 4692-4709 Phase I cab, nose wings.

UP 4710-4734 Phase I cab, flare with 2 panels, nose wings.

UP 4735-4836 Phase I cab, flare with 2 panels, full Building America scheme with wings & flags.

UP 4837-4849 Phase II cab, flare with 2 panels, full Building America scheme with wings & flags.

UP 4850-4868 Phase I cab, flare with 2 panels, nose wings.

UP 4869-5126 Phase I cab, flare with 2 panels, full Building America scheme with wings & flags.

UP 5127-5231 Phase II cab, flare with 4 panels, full Building America scheme with wings & flags.

In HO Scale, Athearn has chosen to model many of these odd ball units, and mostly every range of numbers in some way.  Kato makes the flared units in N Scale.

©2007/2020, Josh Baakko, https://www.modelrailroadtips.com