Broadway Limited Union Pacific SD40

I recently found a Broadway Limited HO Union Pacific SD40 at a very reasonable price. What impressed me was that in the past, Broadway Limited diesels have tended to be "generic" models with minimal road-specific details other than paint schemes. This model, which is a recent Paragon 4, is a major exception, more comparable to ScaleTrains or Athearn Genesis, with both road name and unit-specific details.

In part, this threw me off. Previous models of UP SD40s, like the Kato 1990s HO version, have taken the easy way out, being based on the UP's first two orders of SD40s from 1966, numbered 3000-3039 and 3048-3082. These were plain vanilla with the exception of strobe lights on the cab roofs of at least some units. But when I got this model out of the box, the first thing that hit me was the trucks, which had a third brake cylinder and clasp brakes, unlike the 1966 locos. The number also bothered me, 3117, which made me think intuitively that this must have been an SD40-2 number.

So I went looking for more info. The Don Strack Utah Rails roster clarified the number: the UP had a third order of SD40s in 1971, just before the switchover to SD40-2s, numbered 3083-3122, and 3117 would be in this series. This third order was completely new to me, and I thought I was pretty familiar with the UP roster.

I went looking for prototype photos on the web, and the 3083-3122 also had trucks with the extra brake cylinder in the center. The one big difference between the prototype photos and the model is that at least one photo shows that 3117 didn't have a plow, at least at the time of the photo. On the other hand, photos do show other units in the series with the large SD40-2 style plow on the model, and 3117 may have had a plow at other times.

Based on the Don Strack page on UP diesel paint schemes, the paint acheme on this model would date it between February 1984, when the UP changed the color of trucks from aluminum to gray, and June 1986, when classification lights were painted over. However, according to Strack, rhe UP had stopped using class lights some time earlier.

BLI Paragon 4 models have capacitors to improve the sound decoders' performance on dirty track. This loco continued engine sound and lights for about one second after I turned off the DCC track power. The headlights, class lights, number board lights, and cab lights are all separately controllable via function keys on the DCC control station. UPDATE: To control the individual features, you need to set CV 128=1 for "pro mode lighting". Unlike the highest-end recent models, the BLI SD40 doesn't have step lights or ground lights.

My biggest problem with the model was couplers. Both ends of the model come with long-shank Kadee compatible couplers in a proprietary coupler box. While I like long shank couplers when they're used with a plow, on this model, as with the UP prototype, only the front has a plow, so I wanted to replace the rear coupler with a standard-length Kadee 148. The openings for the couplers in the pilot plates on the model will fit a 148-size box, but the mount for the proprietary BLI coupler box is too short for a full 148-size Kadee box. Thus I had to spend a fair amount of time trimming the 148 box to fit, but once I had removed material from both the front and rear of the 148 box, I waa able to install the new assembly with the BLI screw.