Modeling IAIS 325 in HO

By Joe Atkinson
More information on the prototype IAIS 325

For IAIS GP7 325 I started with an Atlas GP7. 325 was originally UP 725, then UP 125, then Precision National 125. As built, it was configured for long-hood-forward operation, but after going to PNC, it was set up with the short hood being forward. For purposes of "front" and "back" references in this document, I'm assuming the short hood is forward.

On the frame/walkway, I removed the footboards, ground off the cast-on pilot details with a Dremel tool, added new styrene pilot plates, and notched the upper corners of the pilots.

The cab is basically stock with added details. 325 used to have its firecracker antenna centered on the cab roof, but it's since been moved to the short hood. However, the original base and conduit to the back left corner of the cab remain. The base was modeled with a square MU jack, with a piece of wire for the conduit.

On the long hood, the dynamic brake fan was removed and a rectangular plate was made from .010" styrene to cover the hold left by the fan. The DB blister grills were also plated over with .010" styrene. While on the UP, this unit had a winterization hatch over the #3 radiator fan. The hatch has since been removed, but the frame remains visible. I represented that with strips of .010" styrene.

The headlight was relocated down between the numberboards on both the long and short hoods, as UP 125 originally had a Mars light in the high position. On the long hood end, UP specified lower numberboards, so a portion of the Atlas long hood end including the numberboards was carefully cut away. A similar but slightly larger piece was removed from a second Atlas GP7 shell, turned upside down, and reattached to 325's shell after filing to size. A lot of puttying and sanding was then necessary to hide the seams. I used the larger piece from the second shell since so much of the first was lost in the process of cutting it away. Also, cut down Cannon doors were sanded as thin as possible and attached below each numberboard on both ends to represent the access doors on the prototype.


IAIS GP7 325 - Atlas GP7 with dynamics plated over, lowered rear numberboards, and new access doors under front and rear numberboards. The Atlas handrails were kind of thick, so I bent new handrails from wire and drilled out the existing stachions to accept them. Since Atlas' frame is all metal and I don't have a mill, I represented the cutaway sill above the fuel tank with paint. Not the best solution, but the model is a great runner, so I wanted to put it to good use.
Rear engineer's side view
Long hood end showing lowered number boards and new access doors below.

Rear conductor's side view
Front conductor's side. I wanted to honor our esteemed moderator for all the help he's been to me, and I figured a model of his favorite IAIS locomotive was the best place to do it. "Allan Hunt" decals courtesy of the Oddballs IAIS diesel set, as are the "Work Safely" decals in the stepwells.
Roof shot showing plated dynamic brake fan housing and the remains of the winterization hatch surrounding the #3 radiator fan.