The diagram below shows the plan for layout. It was a double-track mainline running between two yards, with a branch line off of the larger of the two yards. The design would have allowed me to run two trains, each leaving from a yard in the main room, and each arriving on the other track at the other yard, again back in the same room. I thought this idea would work particularly well when we had visitors over, so that the trains could be running, unattended, and yet they would arrive back in the same main room, without me ever having to move.