MTY's breaking the N-G distribution model



I found another photo on Shorpy I was not aware of:

Barstow, CA, 1943, ATSF yard.

Notice the string of ATSF XM's to the left of the hoppers - every box car is ATSF. In addition to that specific string, there is a real shortage of foreign road cars in this picture. Did Barstow have an MT yard?

I think we have all reached general agreement that the N-G distribution model for box cars is well supported by the data, at least for WWII.

I previously postulated that while the N-G model is good for the car distribution averages on trunk lines, I think this photo helps support the concept that it may not be accurate for individual trains with significant MT consists.

Even though this is a yard, I find it hard to believe that a yard crew would split up that string of ATSF box cars just to intersperse other RR box cars in it when it left (and it may have arrived as a consist.) I also suspect that the string must have been MTs - hard to believe a consist of loads would be 100% ATSF box cars. Loads no, MTs yes.

Taking Cover,
Dave Evans

---In STMFC@..., <devans1@...> wrote :


I'll take responsibility for that quote, I don't think it was from Bruce.

I suspect the bias from MTY routing on mainlines was hidden in the data analyzed.

But it is very real.

It is very difficult to find a picture of a WB NYCentral boxcar on the PRR's Pittsburgh division. The NYCentral had the second largest boxcar fleet in the country, but on this stretch of what was one of the US's busiest mainlines (over 4,000 WB freight cars a day throughout WWII), the MTY's outnumbered loads by a significant margin, yet just about every western road (including NP) is captured in photos of WB trains. Bottom line is that an MTY NYCentral box car would never be routed west from Harrisburg to Altoona, and if one happened to be unloaded in Altoona, it would be sent EB up the Bald Eagle branch to Newberry Junction.

While loads were only about 25% of WB traffic on the division, I doubt east coast PRR freight agents faced with a flood of MTY Western road cars at the ports would use a NYCentral car for a WB load that wasn't terminating on the western part of the NYCentral. Why do that? Use a western car to get the mileage and stop the per diem, or a PRR car for that load. An MTY NYCentral car? Dump it on the Central at some obscure location in central PA so they have to work it back into their traffic patterns over a secondary line. Nasty...

If the wheel reports for that division could be analyzed in detail, I am confident the data would reveal that traffic pattern - unfortunately such data does not exist (not that any PRR fans have reported.)

I will readily confess that this is a second order effect, but the routing of MTY's can have implications similar to captive service and branch line traffic on freight car distribution, especially for the larger roads that had so many different interchange points such that MTY's did not need to be reverse routed for roads they interchanged with, and in some cases (rule 2-E) even with roads they did not interchange with (e.g. the Rule 2E GM&O/ B&O example I posted earlier.)

Since EB traffic on the PRR's Pittsburgh division was 98% loads, I expect G-N to work very well for EB non-mineral traffic (around 3,000 non-mineral loads per day).

The key, for me, is that modeling WB Pittsburgh Division freights should have consists very distinct for different freight trains, depending on their destination (towards Chicago or towards St. Louis), and a noticeable reduction in Eastern road cars because of MTY routing rather than the more random nature of where loads were destined. I suspect many others modeling Class I mainlines, and some branches of the majors, need to consider the same effect if their location and era had significant MTY traffic. Smaller roads with only a few interchanges and their branches - never mind...

Dave Evans

---In STMFC@..., <Lake_Muskoka@...> wrote :

That is not correct.  My theory applies to all foreign road boxcars w/o regard to lading, WWII years to somewhere in the mid 50’s, mainline routes. 

Dave Nelson

From: STMFC@... [mailto:STMFC@...]
Sent: Monday, June 19, 2017 8:01 AM

The G-N model applies to loaded Box Cars….



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