One possible operational procedure: there might be 3 positions, which I'll call unload, load, and dispatch. When a cabin has been loaded and released by cast, it can move into the dispatch position, ready to replace a cabin entering the loop. Then the cabin in the unload position can move into the load position, making room for another cabin to enter. If the system is smart enough to know that a cabin needing to be unloaded will arrive within a few minutes, it can hold the loaded cabin in the dispatch position until the unloading cabin arrives. Otherwise, it can dispatch the loaded cabin and pull in an empty cabin.