keystoneaholic, on 20 November 2022 - 01:13 PM, said:
You can never have too many X29s! Even if you are not in Pennsy country the chances of seeing them regularly was high. There were so many of them around that a significant proportion of photos of freight trains or yards will feature at least one.
There is an interesting fact that explains that: Both box and flat cars were free rolling; that is to say once unloaded they could be loaded again and sent farther away from home rails. There was a magazine ad from MONON that documented how their first, ummm, IIRC PS-1 boxcar left home rails and did not return for 4 or 5 years. This effect on a national scale meant free rolling cars would be dispersed across the US in proportions roughly equal to the percent each owner contribute to the national fleet. IOW, back in the day PRR had 12% of the US boxcar fleet; Data from wheel reports*, when added up, shows PRR boxcars were roughly 12% of the foreign road boxcars you'd see on any railroads mainlines. NYC had 10% an its cars were 10% of the foreign road boxcars seen and on down the list.
Of interest are CP and CN. They had the 2nd and 3rd largest fleet of Boxcars in North America but only about 10% of Canadian loadings went south of the border. Looking at sighting of foreign road boxcars, their road names showed up only 10% as often as one would expect if there was no border.
*(...wheel reports): I have this data and did the original analysis for the above. Wheel reports were used instead of photos as wheel reports show the whole train out on the road and photos either show hte locomotive and a few head endcars or oddities that inspired a whoa-look-at-that photo. The topic was hotly debated on the Steam Era Freight Car list (STMFC) and when the dust settled there was general agreement that it was a valid understanding. WWII was the great mixer, the Koren War did it again. I do not have wheel reports from the depression or the late 50's so I have nothing concrete to say about them but I will speculate that the need for boxcars in the great plains to move grain often called for cars from across the nation -- mixing, and the rise of covered hoppers in the national fleet in the 50's had the opposite effect.