Just some info from a fellow model railroader. This “helix” as they are called are typically vertical in nature, allowing the trains to move from one level to another. Some model railroaders, since they are pressed for space, will have one level over another (like bunk beds) to double the amount of real estate in the same space.
Also, it’s normal to have multiple locomotives spread out within a consist of cars to spread out the traction - just like in the real world.
