Re: fleet composition


devansprr
 

Mike,

Did UP have any published freight train schedule and consist books?

The PRR had a pretty extensive freight plan based on hundreds of "arranged freights" scheduled between different city pairs. Times were primarily to protect delivery times (1 day, 2 day, etc.) - all PRR freights ran as extras.

The books have appeared on e-bay, but they are very rare. I was able to buy one and the insight it gives into freight train consists is significant.

There has been a lot of speculation in the PRR world about how closely this "plan" was followed, but we have found data in the PA state archives (saved when Conrail was formed), from the WWII era that does support the theory that the schedules and blockings were adhered to as much as practical.

That should help a PRR modeler to properly populate through freight trains based on origin and destination pairs for specific traffic (e.g. stock cars, reefers, and the PRR's early container service.)

Unfortunately individual surviving PRR conductor consist reports are almost unknown, but some of the traffic study data does show two frequent operational tools specific to trunk line traffic:

1) For really busy city pairs (such as between East St. Louis and Enola yard in Harrisburg, PA), multiple "sections" would be run daily, but throughout the day, not one behind the other as would often happen in TT&TO (PRR main/trunk line traffic was ABS/operator controlled.) Those sections would have similar makeup, simplifying the staging issue.

2) For "light" city pairs, it was clear the PRR didn't like to "under-utilize" locomotives, while still meeting delivery times, so they might combine two different "arranged freights" over some divisions that were common to the two different arranged freight city pairs (e.g. a shorter train from Toledo to Baltimore might be combined with a "short" train from Cincinnati to NYCity while operating between Pittsburgh and Harrisburg, without reclassification.) That would imply that between layout runs, two through trains in staging could legitimately swap the back halves of their trains once they returned to staging before heading out again as different trains. While car numbers would be repeated, the unique nature of the consist of the now four trains out of staging might be quite reasonable.

I wonder if any such behavior might be detected in the Fraley books?  (e.g. break the stats for trains into front half and back half, and see if the different halves begin to correlate.)

Empty routing/blocking can also be quite revealing. On the PRR, over significant portions of the mainline, it appears that western road WB empties may have been blocked to either Chicago or St. Louis pretty far east in the system. So WB ATSF empties would not appear very often with WB GN empties as they traveled west of Harrisburg (and WB NYC empties would not be seen at all.) So while the N-G theory on boxcar distribution should hold up well for trunk line loads, it would not work for individual strings of empties between certain city pairs (e.g. during WWII one would not expect to see many WB Southern box cars between Crestline, OH and Chicago, nor southbound GN empties into Potomac Yard in DC, since there was a massive imbalance between EB box car loads and WB box car loads.)

The blocking plans for many arranged freights also highlight the perils of deriving any consist information from looking at the first few cars behind the overwhelming number of  "head-end" photos, or cabin-end photos for that matter too.

Dave Evans


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

Tim O'Connor writes:

"I REALLY think this whole issue can be greatly simplified for most
layouts."

Tim goes on to explain that even with relatively small numbers of cars in a
fleet, if a smaller number is used to genrate a train, the odds strongly
argue that the train's consist will be different...even for the same kind of
train [ example, stock train ]. No arguement on that. However, my analysis
of my Fraley was to determine the % of the total number of trains [ 34 ]
that would be considered a particular type of train. I was not trying to
make such trains unique. IOW, I now know that there were about 6 "types" of
trains that could be identified by the car's consists. Their presence in the
34 trains of the Fraley are as follows:

1. Lumber: 9 trains, 26.4%
2. Reefer loaded: 4, 11.7%
3. Reefer MT: 3: 8.8%
4. Stock: 3: 8.8%
5. MT coal: 3: 8.8%
6. MT tank: 2: 5.8%
7. Other: 8: 23.5%

Unfortunately [ I think ] I can't populate my layout with 34 trains. In
fact, I am confined to 8 frt trains unless I use infinite staging or reduce
the number of passenger trains to less than 5. The only time I tried
infinite staging we had several dispatchers screaming...

Anyhow, if I confine to 8 trains, I end up with 2 lumber trains, 2 reefer
trains, one combined stock/MT coal, one combined MT tank/MT other, and 2
other. I can add 2 more trains through Buford staging...probably one other
and one MT other.

Mike Brock

Join main@RealSTMFC.groups.io to automatically receive all group messages.