One thing I have wanted to see for some time was a set of ATSF F-units running on my American OO layout. This pair is now running and ready for final details.

The only F-unit produced in 4mm scale was by Schorr, their bronze F-3’s. The ATSF owned many F-3s but they were all passenger engines, in passenger colors, not what I wanted for freight trains. Looking though I realized they had some F-7s that had a similar look. Specifically, F-7s numbered 259LABC through 268LABC were visually similar to F-3s as they were delivered without the stainless steel grills and had the “chicken wire” openings of the F-3.

These F-units still are not quite right for the prototypes as they have F-3 fans on the roof and the A-unit still has the steam generator details (and neither has dynamic brakes), but visually they are about as good as you are going to get in American OO. Noting as with the recently completed RSD-5 that the blue color is not nearly so “electric” looking in normal light, without the flash of the camera.

Under the hood is the power plant of the A unit. The original builder was Pierre Bourassa, and I think actually it is pretty clear this is the second drive that has been installed. The end with the “open” area had the original drive unit which had a smaller Pittman motor mounted on a gearbox. I have an example of that unit on another Schorr engine (I think it is a type of Baker drive), but he thought it small or it burned out, as he replaced it with this big Pittman connected to a Baker drive with the big drive belt. I replaced the belt and tuned things up–this thing has a ton of power!

The decals are vintage Walthers products (HO) which worked out fine. Note that the open areas in the chicken wire were masked off and darkened. This helps the look a lot. I also like how the masking on top of the cab of the A unit came out.

To what I am not completely happy with, some blue paint got behind the masking, especially on the lower edge of the B unit but also the same area of the A unit. I thought about re-masking and painting more but decided that cure was a bit risky. Instead I will follow up with some weathering at some point to blend things a bit more. More difficult to fix, I did not realize there should have been a shape to the masking right in front of the cab windows until it was too late, so I have to live with that error.

The models are not quite done, there are areas left to paint black as of now on the shell and a few details to add. But even now the engines are in much better shape than when they came to me which is a goal I try to keep in mind. Looking forward to running these on freight trains!