Good Morning RD,
I had a little time this morning before the workers arrive, so I tried a new approach to your layout design. Instead of separating the levels, I separated the individual "runs" and changed track colors to show levels and grades, along the lines of what Carl suggested. The layers I used are:
- Track 1 for the main run.
- Turntable for the TT and track run leading to the yard.
- Labels to identify grade percentages, etc.
- Bench Work for the white tabletop so you can see the different colored track better.
Here are the main and turntable runs. The Black tracks on the Track 1 layer and the Lt Blue tracks on the Turntable layer are set to 14" high. The darker Blue tracks are lower at 7" and the purple tracks are the grades from 14" down to 7".
RRT's 3D view doesn't make it easy to see the grades, so I added a couple of different views. As you can see, the grade for the track nearest the turntable starts on the right side midway through the loop and the slope for it is 3.4%. You can reduce the slope by starting the grade a few tracks further around the loop. The grade for the other track starts in the lower right corner because it's not advisable to place a turnout on a slope. Either way, both sets of track now clear the run going from the TT to the storage yard tracks.
One potential problem I see is circled in Blue. I'm not sure these tracks clear each other and there is still work to be done to get everything to connect. So, it doesn't make much sense to spend time adding the lower level and yard back in until this level is finished. However, in looking at your latest effort, the tracks going down to the lower level have to clear the tracks on the left side and I'm not sure the slope is going to be acceptable, especially given where you placed the 2nd turnout. The last photo shows what I'm talking about., Those Purple tracks need to go under the Blue tracks and there's no way there's enough room for an acceptable slope. The Blue tracks are at 7", so the Purple tracks need to be at 0" before they cross. This is a problem whenever you try to convert an HO design to O scale. While the overall space needed may not double as Carl suggested, acceptable grades in O scale require a lot more room and I'm not sure we can overcome that.
Workers are here, so I need to go. Good luck!
