Re: Freight car distribution


devansprr
 

--- In STMFC@..., Bruce Smith <smithbf@...> wrote:

Dave,

If you've read my article in TKM on the PRR fleet ;^) you know that
the PRR averaged around 50% home road, but that includes about 75%
home road hoppers, 50% home road gons and 25% (estimated) home road
boxcars. Those numbers also reflect cars stored or awaiting repairs,
so the actual number in trains is slightly less.

For the rest of your boxcar fleet, the NYC cars should be roughly 6%
of your total fleet. Thus if you have 100 non-PRR boxcars, six
should be NYC. Of those cars, a substantial portion should be the
USRA steel boxcar (Westerfield, and styrene?(someday).


Regards
Bruce
Bruce,

Pretty sure I have read ALL your TKM articles, and greatly appreciate
your efforts.

But I'm still not convinced on NYC boxcars. I certainly plan on more
than 1, but looking at pictures I rarely see NYC box cars in through
freights on the PRR Middle and Pittsburgh divisions. But I think I
recall seeing several at the Altoona freight house.

I think it is legitimate to bias populations based on the local
situation. Isn't it likely that nearly all NYC box cars loaded in New
England, with destinations in the upper west - west of the
Mississippi, would be routed over the NYC's water level route if they
touched NYC rails before PRR rails? Or would most shippers specify the
entire route of their shipment?

And east bound MT NYC boxcars from the west (admittedly VERY rare
during WWII) would probably be interchanged onto the NYC well west of
Pittsburgh.

To me, that would make west bound NYC box cars through Huntingdon, PA
less frequent than EB CB&Q loads, which is what the photographs seem
to indicate, even though the NYC fleet was bigger than the CB&Q.

The Altoona NYC sightings also make sense. As one of the world's
largest railroad car and locomotive shops (the largest during WWII
era?), there must have been a steady stream of parts and materials
flowing into Altoona from all over the North-East, and many of those
suppliers would have been served by the central, hence some NYC box
cars end up at the Altoona freight house.

Clearly Mike's UP reports show SIGNIFICANT deviations from the
averages. Lacking wheel reports, I'm more inclined to work off of
photographs from the locations being modeled rather than national
averages. National averages can help fill in the gaps where no other
data is available, but the science behind operations research would
suggest that significant deviations from the average are the NORM, not
the exception. Freight car movements were not a random process, and
therefore should not be expected to exhibit standard deviations
typical of Gaussian distributions.

I realize I'm not at the modeling level of this group's membership - I
monitor for the wealth of information provided, but I have limited
time, and frankly limited modeling skills, that are necessary to build
a bunch of resin NYC box cars, so if NYC ends up being 1-2% of my box
car fleet instead of 6%, I'm not losing any sleep over it, and if
anyone complains about a shortage of NYC box cars during a future op
session, I can confidently reply "not today", and know that it is a
"prototypical", and statistically reasonable response.

Respectfully,
Dave Evans

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