I'm looking to redo my current layout, as I've had my current setup running for a while and have gotten the itch to change it (and if I'm honest, I have the most fun doing that anyway). My overarching goal is to run as many of my locos on the layout as is practical, and since I'm limited in horizontal expansion, I will need to do multiple levels. I did do a second level with the Lionel elevated trestle set some years ago, but was never happy with it. So first off, I'm looking for suggestions on how to build sturdy supports for a second and possibly third level. Also, I'm not trying to model a particular scene, era, yard, etc., so the supports don't have to be realistic, merely functional. I'll be using 3-rail tubular track, with mostly O-31 curves and 022-style switches (exceptions noted below). I have one Lionel LionChief Bluetooth loco, but the rest are conventional, a mixture of pre-war, post-war and modern (1990s plus).
I'm starting with a 8 foot square baseboard as follows (images from SCARM):
This started out as a 4x8 foot train table (the large section on the right). The two 2 foot "bridge" sections and the snipped 2x8 table on the left were added later, to accommodate an O-72 loop (I have one consist that requires O-72). This *just fits* in the room it's in, so there is no opportunity to make the perimeter larger (in fact, the snipped portion on the lower left was necessary to allow egress into the room). I might be able to get another inch or two by shaving the cutout in the middle, but while the room isn't getting any larger, unfortunately I am 
, so I'd like to keep as much of that cutout as open as possible. For the lower level, I was thinking about something like this
By electrically isolating the two sidings on the left and two other sections on the outer loop, I can have two trains in the sidings while another is running on the outer loop, and can switch out one of the trains on the sidings at a time. While this is interesting, it still only allows me to run one train in the outer loop and another on the smaller, inner loop. I can't see a way to get more.
For the second level, I have a simple loop, like this, where I envisioned running the Bluetooth loco:
And for the third, my O-72:
The track elevations on the diagrams can be changed if needed. I just set numbers to differentiate the levels.
All together it looks like this (messy):
or this:
I also have some O-27 track and a pair of 1127 switches, and also a 45 degree crossing I could never figure out how to place in the layout.
I have very little experience with multi-level, and am looking for suggestions on how to do something sturdy that would allow for good views of the running trains. These diagrams are just some initial musings to get started, and would allow me to have four trains running at once, with two more on the sidings on the lower level I could switch out. The O-72 consist is my favorite and I do want to be sure I can accommodate that, but I am not set on having three levels. If I could get four trains running on two levels, that would be just as good. Ideas welcome...thanks in advance.
