Although box cars might be unloaded and sent homeward empty, they were free-running, which meant they could be confiscated by the host railroad and used for any suitable cargo. The intent was to reduce empty mileage on such cars and allow them to be loaded in many directions. The AAR Car Service Rules provided a guideline for choice of these cars, as summarized in the back of many issues of the Official Railway Equipment Register (ORER), in E.W. Coughlin’s fine book, Freight Car Distribution and Car Handling in the United States (AAR, 1956), and many other places. Here is a summary of those rules (click to enlarge):
The reference to districts is to “home territories,” in which a railroad would have facilities. Here’s the map:
The result of this approach was that unlike privately owned cars or cars with special equipment or special assignment (tank cars carrying a specific cargo), box cars might well carry a wide variety of cargoes in both directions over a particular line. From the modeling viewpoint, this would mean that some box cars would move loaded in both directions on a layout, with origins and destinations of all the cargoes off the layout, rather than simply returning empty in one direction.
Here’s one example of such a pair of loads, one northward (railroad east) and one southward (railroad west) on Otis’s layout. Note in the first instance that the Seaboard has properly loaded this UP box car to a destination in a home district:
This the second or westward load.
Thus on the layout, this box car will move loaded in both directions. As the base waybills are completed, it will be appropriate to add more waybills to the sleeve for this car (thus duplicating the “four-cycle waybill” approach) for variety. Here’s an example. Again, the SP has properly routed a UP box car to its home district.
Note that the car has an origin for this eastward move (on the Shasta Division) which is far from the previously-shown westward destination of Oakland, California, but all that matters is that the car moved westward to staging, and will return from staging in an eastward direction.
Of course either a fourth westward load, or a westward Empty Car Bill, would be needed to balance this third loaded waybill, if a strict rotation of sequenced bills were to be followed. But another option is for the person conducting the layout re-set between operating sessions to choose either westward bill whenever the car needs to move that direction. There could even be more than four cycles in a sleeve to make this process more flexible.
Another area of concern is open-top cars, which when loaded have visible loads (unlike house cars). Either the modeler glues loads to cars, and arranges waybills for these loads to serve in either direction (while “permanent” empties would likewise have Empty Car Bills to move them empty in both directions), or else one has removable loads, permitting the same car to operate loaded and empty. In the latter case, the inventory of removable loads at the staging locations has to be managed along with the waybills, but the approach certainly allows much more realistic car operation.
I will present more about both the box car issues, and about open-top cars, in a future post.