This Kato Unitrack All DC layout is 4×8 feet. There are four tracks that are interconnected with WX310 double crossovers. The beginning of the video shows how one train can traverse all four tracks in one giant lap.
Since I made the ultimate figure eight layout, I have liked the idea of a double reverse loop. This addition to the layout makes it easy to reverse the direction of any train going in either direction without requiring the train to backup at any time. The only problem with a double reverse loop is the size. I managed to fit one in using 249mm radius curves. These are the smallest curves that most of my engines will handle. Using these small radius curves enables placement of two loops side by side inside the larger outside loop. One of the small loops has the double reverse loop and the other small loop has most of the storage for the layout.
This is my first layout using three WX310 double crossover pieces. One property of these switches is that they do not conduct power through the switch. In my last layout I had a double crossover with power injector track on both sides. That was not possible in this layout because two WX310 pieces were separated by only curves. All my power injector track is straight. To solve the problem, I used terminal Unijoiner connectors between the curved piece and the WX310.
This is also my first layout with five power supplies. Each track has its own power supply. The double reverse loop uses the fifth power supply. Insulated Unijoiner (Kato 24-816) connectors were used to isolate the loop area. One power injector track was inserted into each arm. The polarity was setup so that trains moving left to right would be forward on the power supply and in the opposite direction would be in reverse on the power supply. Another set of Terminal Unijoiners was used to power the elevated section of the layout.
This was a very fun layout. It took about 90 minutes to setup and get the power working correctly. The SCARM file is here.