Your right I was thinking about my O gauge which the smallest is 48 and the largest 96 diameter, The HO gauge is 34" . I have a spectrum steam 0-6-4 that will not run on it without removing the front 4. But it is to light for what I am pulling. I have an old Hershey's (Bachman) with engine number 1993 that runs fine and pulled 20 cars for years, at 8 per week that needs a new motor now. Wanted to get a few more heavy engines that would pull the load, with sound. Their is only 4 curves in the layout and no turnouts as this is just to show the size in our store. I am a Lionel O gauge guy (and dealer) and HO is just a second thought to me. Know next to nothing about it. Have some NZ up on a standalone rail just to show the difference in gauges. Just looking for a good HO engine that is dependable and as the 1993 was a great engine for a ready to run set, I am going to stick to Bachman.