Walking down a well worn path from long ago;

In the late steam era, 1940-late 50’s there is a general rule you can consider for both box and flat cars; set aside a percentage for home road cars, more if the economy is not so good, less for robust years, more for out of the way locations, less for urban areas or mainline routes. 20% is a good number to start with.  The remainder, foreign road cars, will closely hew to the percentage road has relative to the total population of those cars,   meaning that if the PRR has 12% of all US boxcars, plan on seeing 12% of boxcars on your layout as PRR cars.  Not every train, not every day, but what will occur over a period of time.  NYC has 8-9% and so on.  Easy to do if you have space for 100 foreign road cars, much harder if the space allows only 25.

The reason for this is that ordinary boxcars and flatcars were free rolling, dispersing evenly across the country, appearing on all roadroads.  There was an ad about a brand new PS-1 boxcar that wandered for over 4 years before returning to home rails.

That said the above is a guide, not the law.

Dave Nelson

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Jim Pattison

Hi Phil, I don’t have any of the conductor’s train books, but that work has already been done for the SP Coast Line by Tony Thompson.  The questions I imagine asking are along the line of, is the Bowser model of a Wabash round top box car correct, sort of correct, or totally wrong?

Jim Pattison

Bruce is correct.  If you dig into the archives you will find plenty of discussion on this topic.  I don’t recall now when I first posted about it; Tim Gilbert joined in shortly afterwards and wrote far more extensively that I did.

The “rule” we advocated was an even distribution of box and flat cars on mainline routes from around the start of WWII to sometime in the 50’s.  By even distribution I mean numbers proportionate with the ownership numbers from each road.

For my part I tallied over 1000 foreign road boxcars on a mainline in North Carolina from wheel reports. The sum of each foreign road was sorted highest to lowest and then compared to an ordered list of road names showing their total numbers of boxcars.  The two ordered lists matched up well down the list, finally pulling away from each other (IIRC) down in the 1% and less totals.  I then compared the percentages and with one or two very minor exceptions they too matched.

There was no data available to me from before WWII or after the mid 50’s, nort was there any data for way out in the boonies branch lines so the rule is qualified accordingly.  Additionally, I have examined urban traffic and was surprised that the number of house cars were much less than I expected. I do not know if that was a unique case but it does occur to me that with a large flow of inbound boxcars there might be very little need for roads to hang on to home road cars for protective service.  The opposite may well be true for very far out in the boonies, low traffic locations – few inbounds might mean more home road cars are needed for protection.  Both of those opinions could be useful to hobbyists.

As for the data I had, for example, running east out of Knoxville TN there were just as many SP, ATSF, and GN boxcars spotted as their ownership percent of the national fleet suggested would be seen.  If regional weighting was present that would not have been the case. So let’s dismiss the Kalmbach “theory” of regional effects.

Tim Gilbert’s research showed the same was true for flat cars.

Looking at the data there I could find  no such relationship for any other type of cars and that sounds right because many of those cars either did not leave home rails or if they did the numbers were quite small.  Consider stock cars: Texas was the state that provided California more cattle than any other state – and it’s a decently long run.  The problem is both SP and ATSF do all the way between those two points so those cars never had to leave home rails. 

Another example: There is photo evidence of NW hoppers in Indiana and MP hoppers in Utah. Turns out this was low volume shipments of coking coal headed to steel mills.  They were on a regular circuit and so unlike box and flat cars they did not wander about to be spotted off that circuit… they were simply out and back loads.  Almost all tank cars were on a steady circuit between two locations… no wandering.  Reefers did wander… but the available data is not large enough to draw a good conclusion.

Dave Nelson