Regarding NP boxcars, and why Mike can state “and an NP boxcar in every photo”.
From my own research digging through the NP Corporate files at the Minnesota Historical Society, specifically the files the NP Mechanical files or other files addressing boxcar shortages.
I'll address the comment on hauling lumber last and give the fleet numbers up front.
First: NP home fleet numbers, about 40K overall in 1940, a number I believe the AAR strongly recommended (carrot and stick) for each railroad based on a number of factors. Something about the term: To protect home car loading requirements, sounds familiar. I know there was a formula for car ownership, per railroad, just don’t know what it was. Perhaps someone within the industry can shed some light.
Those numbers dropped slightly over time. In 1930 it had been 47K, not including ore cars.
In 1940, about 23K of the NP fleet were boxcars. Many single and doubled sheathed wood. Wood sheathed boxcars kept in service later than many other railroads.
Given that the industry as a whole was transitioning from thirty six footers to forty footers to fifty foot boxcars, and fifty ton gons to seventy ton gons, makes sense to me that boxcar numbers might drop over the years.
Then almost 7K gons or hoppers, with an overwhelming amount being gons until 1955, then hopper predominated.
Next almost 2600 refrigerator cars. (This does not include the part ownership of MDT and other leasing.) Perhaps a bit more than you wanted to know.
However as I have provided via links and photo postings prior that the NP wooden sheathed cars were kept in very good condition right up to the end, which for the retirement dates of many of those wooden cars, was after the date of this list.
Back to boxcars.
On December 31, 1952, there were 19,191 boxcars. Slightly over 14K were all steel. 4280 were wood sheathed on steel underframe and steel sheathing. 960 were essentially wood cars with only a steel center sill, however wood underframe and rather old.
The NP boxcar fleet other than that one quarter was younger (on the average 25 percent younger) than the national fleet. This number comes up again and again in the files researched. After decades of research (like many others here) I think that 25 percent younger car life has a lot to do with seeing NP cars all over.
Of the wooden sheathed older cars and as I have mentioned here before, the NP shops and corporate were very proud of the good maintenance and condition of the Northern Pacific cars. That I think, was the primary reason these cars went off line and stayed off line for so long. A clean, tight, well maintained boxcar. Isn't that what a shipper wants? And that accounts for the wooden cars being seen again and again in photos.
Of the above, I do not mean to dismiss the numbers or reasons others have posted.
I would like to talk more about this here however I think that a presentation for the 2019 Naperville/Lisle RPM and CCB meets is in order and I want to keep some of my powder dry.
I will present on NP boxcars and some of the rest of the NP fleet cars, also on the major shippers of the NP, and the revenues that these brought home based on early 1950s numbers. Also car loading numbers per industries like lumber, grain, etc.
Many of you seem to have purchased recent NP car offerings and the least I can do is to give you avenues to properly model and waybill them.
(And I have nothing to gain financially, perhaps though the interest of mfgrs on further NP offerings.)
And after CCB I will get the data on-line.
Now, of hauling lumber. I'll say a very good guess.
However SP, GN, and MILW all hauled lumber as did the UP. So why doesn't Mike say " And a GN, MILW, NP, SP, and UP boxcar in every photo" ?
I will have the extended trips of five NP boxcars as part of the presentation, many of these lasting over a year off-line. Several of these had no lumber shipping involved, at the start or otherwise.
And routing with all respect to Car Service Rule 2, from studying those five cars - does not seem to apply. Rule 1 perhaps?
The only conclusion I can draw, is the interior and exterior condition of the cars, being kept to high standards made these cars more likely to be diverted. As I had stated in a thread earlier, dealt with the irrational desire in us all to covet good things. And in that, to more likely have a car clerk keep a car local and send it out locally, to please a nearby shipper.
The Northern Pacific route was a longer route, West Coast to Midwest, than the later built GN or MILW. They could not state they were the shortest route. They could compete with service though. Keeping the cars in good condition I think (and yes I will admit to a bias) was I believe how they did it.
And why Mike could state his corollary about NP boxcars.
James Dick - Roseville, MN