On my two rail layout, I can run conventionally since the power supplies are Bridgewerks DC packs. When I run MTH locomotives, I use DCS fed by those two, two handle DC packs at 18 VDC, and this power is routed through two of the four channels of each of two TIU's. I have a four track mainline, and use two TIU's since a single four terminal TIU will not pass DC on two of its channels. I can mix the power on each of the four tracks, since they are electrically isolated from one another. For example, I can run DCS on one track and operate the remaining three tracks conventionally. (The layout does have crossovers, and they are each electrically insulated.)
I have a number of USH, Westside, and PSC locomotives and wanted to retain the ability to operate them. Each of the four mainline tracks and the yards and siding have blocks, using toggle switches. (I also have a two track, 3-rail layout on those same tables that can run conventional or using DCS. That trackage is also divided into blocks.) The layout was featured in O Gauge Railroading magazine in the August/September 2008 issue.
I am enjoying the intricacies (and frequency) of the ATSF early diesel locomotive road numbering system, since I do not understand it and it defies any logic to me! I might be able to answer a question about NYC though.....
