Andy,
            here is a link to a Rock Island car photographed by John Vashon at the Minneapolis Pillsbury "A" Mill. 
https://www.loc.gov/resource/fsa.8a04504/       and the photo at a much higher resolution   https://tile.loc.gov/storage-services/service/pnp/fsa/8a04000/8a04500/8a04504v.jpg 

Gaps between the boards?  To quote Roger Rabbit - Pleeeeeaasse.    I'm not sure if it is a mastic oozing out however it is clearly proud of the surface.  Not gaps.  

Railroad house cars have sheathing to protect the commodity, as soon as they gets gaps or are warped to any great degree, the cars become practically worthless and generally speaking shippers would reject them.  
                                                                                                                                                                                                                                                   Jim Dick - Roseville, MN 

Schuyler writes regarding oversize gaps on modeled cars: Are we only talking to ourselves here? 
      I think that it is very possible that we are. And then there could be the same who feel that even this conversation is - nuts! - to lean upon researchers "bell curve"    https://www.simplypsychology.org/normal-distribution.html 

The NP 6000-6999 series cars built by General American Car Company in 1923 were the NP's desire to get a larger share than they had of the automobile market. I have written prior that when the NP had Detroit area traffic agents made inquiries on how the NP might get more traffic, they found that they needed to have empty cars at the ready locally to the auto plants.  GACC was approached and asked if the NP could have cars delivered ASAP and GACC stated that they currently had jigs in place for SP cars of generally the same design and would the NP accept SP clones? Though the NP and SP were on quite amicable terms with (with the President of the NP often spending lengthy holiday visits with the SP President) the NP Mechanical department wanted a more substantial floor which had letters back and forth to the point GACC stated that a decision had to be made or else the NP could go back to the end of the order line which was 9 months at best, more likely a year. 
       About 10 years or so after they were built, some of the cars (500) of the then 998 cars were rebuilt into the 30000 series with single six foot door instead of the original door and a half six and three foot doors.  Many of these cars soldiered on well through this lists end date BTW as appliance cars, grain cars, general service going all over.  
   
     I had a conversation with a resin caster while turning over a mailing tube of plans on the 6000/30000 series NP cars about 6-10 years ago at CCB and made sure to mention my concerns about "oversized gaps or overly distressed and warped boards".  Something, after decades of reading letters of the Mechanical department and elsewhere, that stated the NP wood sheathed cars were generally maintained in better shape than the industry as a whole and I relayed that to this person. 
      While a completely cordial conversation, the reply as I recall had something to do with the total market in that there were sales to the toy train modeling aspect (my words, not his) and that this part of his sales which (paraphrasing his words) were people whom he doubted would ever assemble his kits however were fascinated by how the model looked in their display. And to these people - seeing oversize gaps and deep graining was actually part of the appeal.  He gave me what he felt was an estimate of this group of his sales and said (paraphrasing again) as long as they put bread on his plate he was not going to go out of his way offend them. I'll go on to say that I think the person and the company are very good folks and have added many, many, good models to our model railroad realm.    

     The corollary is of course that folks who desire greater fidelity are in part, held captive by these people however well meaning, do not care, none the less make purchases in the margins.   
And of course higher fidelity has lead to some price increases - which to me only makes sense.
Quality invariably costs more, I accept that.
However in this list can be found opinions of those who feel otherwise regarding cost increases.                                                                               Jim Dick - Roseville, MN  

 

 

 Schuyler, 
        until you called this out I had never noticed this X-bracing either.   Of the cars found in this grouping I do not recall seeing a larger image of this car. Looking back again there does not seem to be one that includes a road name.  Of the number on the underframe, on the NP a 200xxx number indicates company service, and this car is clearly in general service so not NP. 
                                                                                                                                                                                                                                                      Jim Dick - St. Paul, MN   

The Tichy USRA boxcar really sets the standard for planking on boxcar sides in my humble opinion.

I agree.   Almost all models of single sheath cars have grooves molded in to delineate separate boards, and those grooves are way too large.  As Andy says, those "grooves" just don't show in this photo.   The don't show up in most photos (and that goes for wooden passenger cars too.).  The Accurail single sheathed cars (4200, 4300, and 4500 series) do a much better job here--the casting shows boards at slightly different levels with no grooves between them.   As far as I'm concerned, they are the best in the business.

Steve Kay

This is a very poor resolution photograph:

https://www.flickr.com/photos/barrigerlibrary/12293485546/in/photostream/

But is that part of a Missouri & North Arkansas boxcar on the right?

Jim Gates

I also think this is a black roof.  There's a significant contrast between the tone of the vertical side extension and the overlapping edge of the roof panels. The contrast is pretty clear on the left half of the car, but obscured by light colored weathering to the right of the door.

Jack Mullen