What I needed was to find a way to expand my collection and to be able to run both my new and my older loks on the layout. So I have designed and built a moving storage yard with three levels. I purchased a rack from the Grainger Company (Bryan Adams, a fellow Marklin enthusiast works for the company) consisting of five easily movable (up/down) shelves, made of chrome stainless steel, and on wheels. The rack is 60 inches high and each of the five shelves is 72 inches by 24 inches giving me plenty of additional storage space. The shelves are easily movable up and down which makes it very versatile.
Since the rack is on wheels I can easily move it out of view into a storage room or move it from one ramp to the other. I simply shift it from one siding to the next when I want to store or move a consist onto or off my layout.
I covered each shelf with 1/4 inch plywood so that I could screw the C track to the board. I now have 18 storage sidings, each 6 feet long. Great for long consists that you don't want to separate.
The rack, as I call it, allows me to move loks and consists on and off the layout with relative ease. In fact, it is fun moving a consist and its lok onto the rack then changing loks for a new consist. No need to power the rack since it gets its power when I connect to the mainline.
I used C track for ease of construction. (I was never a C track fan, but after using it for this project I wish my entire layout were C track.) I realized, however, that if I only backed a consist onto a siding I would only need C track at the head of the siding where the lok would stop and could use M track for the rest. I used the C track because of its good conductivity for digital loks. I didn't need that conductivity for the passenger coaches or freight cars in a consist. I will be replacing 2/3 of the originally installed C track with M track and will use the C track for my main layout wherever possible(especially in hard to reach places).
Initially I had two 3-way switches and two turn-outs on one level. I removed them because they reduced the length of the siding. I only need to connect a single siding to the layout so having switches served on purpose.
I also have contact tracks on each siding but that presents a problem since I will have to run a ribbon cable back to my other S 88's and I haven't quite figured out how to do this.
To reach the upper level shelf I built a 4% grade ramp which rises 6 inches above the layout. I added a stone facade to the ramp and railings to make the ramp more realistic.
For me, this system works well. Hope it gives some of you ideas about getting more use out of your layout and loks.