@prrjim posted:The PRR Mainlines were heavy rail as mentioned above. So Code 148 would represent that well. I would use code 125 for sidings. I'd be tempted to try code 100 on industrial track, but not sure. I do have some older steamers and the flanges may be just big enough to hit the heads of some spikes if not totally tight down. I have had no issues at all with code 125. My yard and ladder tracks are all code 125.
So, how do you transition from 148 to 125 or any other step-down situation?