Pennsylvania X41B Underframe

 

The (mostly) finished underframe, as described in the following text with photos

In my last post, I discussed my recent clinic for the Philadelphia Chapter of the PRRT&HS. Part of that presentation was about modeling PRR welded box and auto cars and specifically, the work begun on a Sunshine X41B. This post continues that. The focus of this post is the underframe, which is scratchbuilt and relies heavily upon etchings. The images herein provide a mostly step-by-step look at how I replicated the X41B underframe, continuing what had been presented in the clinic. Note that the X41C underframe, shown via photograph in the clinic file, was quite similar, with the difference being that the X41C substituted pressed steel crossties (which can be seen herein and will be noted as such) in place of the two center crossbearers located under the door posts on the X41B, meaning the B had four crossbearers while the C had two.

The image above (all images can be seen in a larger format by clicking on them) was recorded after all the stringers between the bolsters and the four main pairs crossbearers were added. The flanges of the center sills, 0.010" x 0.060" strip styrene were also attached, completing the center sill sections between the bolsters. Note that the crossbearer sections that are located where there are separate side sill support tabs extend past the edge of the floor. This is because these will tie directly into the channel shape of the etched tab sections.

These two images provide other views at the same stage as the photo referenced previously. One interesting (and cool to this freight car geek) thing is the difference in "height" of the stringers between the crossbearers (five scale inches) versus the stringers between the crossbearers and bolsters (three scale inches.) The difference is quite pronounced and shown to good advantage in the photo below. Note that the floor had not been glued into the body (yet!) at the time of these photos.

The floor had a slight bow to it from end to end. In addition, it was necessary to tack the floor into the body, yet leave the areas away from the center of the car "free" in order to ensure proper orientation of the crossbearers and their corresponding side sill support tabs. I carefully secured the center portion of the floor into the carbody with ACC, in the area highlighted in the graphic shown above. This served to secure the floor into the body, yet allowed some "play" to adjust the alignment of the floor relative to the carbody when securing the outer crossbearers and their tab segments.

The preceding three images illustrate how the crossbearers and the tab side sill support sections are integrated and attached. The beauty of the etchings is that they are thin enough in profile to accurately mimic the prototype and yet are still quite durable. Again, note that the ends of these crossbearers extend past the bottom of the side to nest into the channel of the tab.

The crossties were created by drawing the basic shapes with fold lines in the appropriate spots for etching. These came out exactly as planned, nesting into the center sill flanges and clearing the stringers. The ones between the side sill support section in the center of the car required some shortening to fit. The ones at the tab sections nest into the channel "behind" the tab sections. The photos above and below illustrate the crossties.

The side sill support tabs that have been replaced with etched parts are visible in this side view of the model

The lower bolster cover plates feature "knockouts" in the exact shape of the prototype. They were bent slightly to match the shape of the scratchbuilt bolsters.

The image above shows the underframe after the addition of the bottom bolster cover plates, as highlighted in the previous photo

The two preceding photos highlight the addition of the bottom crossbearer cover plates. While I etched pieces for the segments that span the center sills, I opted to use 0.005" styrene as I found it generally easier to work with and the shape is a rectangle, as opposed to the complex shape of the outer portions of these unusual plates, where etching made the work of matching the shape far easier.

The channel section crossties had a small rectangular steel brace that was welded to the crossties and the center sill. This is simulated with an etched piece, as illustrated in the two photos above.

The stringers between the bolsters and end sills incorporated trapezoidal-shaped plate that was welded to the ends of the stringer and to the end sills, tightening things up a little more. These are simulated with etchings, as shown in the two accompanying photos.

While there are still a couple of things before the underframe is completed, including truck mounting and simulated bolt heads on the stringers, as well as the brake equipment, the basic structure is complete. The next post will pick up to cover brake equipment and other details. Stay tuned...

Pennsylvania X41B - one more Sunshine kit started

 

PRR X41B 119058, Fayetteville, NC, Dec. 24, 1951, Col. Chet McCoid photo, Bob's Photo, Collection of J. P. Barger

I recently presented a clinic at the June 22 meeting of the Philadelphia chapter of the PRRT&HS about PRR Early Welded Box & Auto Cars and Models. It seemed that the talk might be a good opportunity to expand the one I did for Hindsight to include some modeling content. I have a couple X41 family kits produced by Sunshine Models sitting in my stash. Frankly, I wasn't certain I would ever even build them. However, the clinic seems a great opportunity to add one to my fleet. Regarding the kits, the body parts are nice representations of the X41 family of cars. However, I have been quite certain that the underframes in the Sunshine kits are not correct for the X41 subclasses and wanted to do a little digging to uncover what would be needed to correct that issue. I also know that the details could use an upgrade and a few improvements.

With the aid of the PRRT&HS, I have been able to determine that not only is the Sunshine underframe not correct, it's really not even close. All this means that in addition to some detail upgrades, I have reason to scratchbuild a new underframe, always good clinic fodder.

Here is a list of a few things to be done as part of this build of an X41B (single door car):

• scratchbuild underframe (that's a LOT for a single bullet point, but I will chronicle that in greater detail)
• upgrade and correct grab irons and ladders (etching will feature heavily in this)
• fix door post brace detail (the castings had some rather soft, "blobby" detail that has to be fixed)
• add trust plate detail (this has a solution with a wow factor it, at least in my opinion)
• decal artwork for a circle keystone revenue car
• determine truck, running board, and hand brake combinations for a car with improved Youngstown doors

Thus far, I have assembled the body and created the basic guts of the underframe (floor and center sill section.) There is one thing with the body assembly that I chose to ignore (ignorance can be bliss.) On the prototype, the roof eaves wrap over the side plate (the top of the side and a custom sloped/angled shape unique to the PRR X40 and X41 families of cars, as far as I know.) On the model, the roof is ever slightly too narrow to achieve this. Honestly, most people wouldn't have even noticed had I not pointed that detail out for you on the model. The Branchline Murphy rectangular panel roof is slightly wider, so it would be a better option... the only hitch being that you'd have to cut and splice two forty-foot ones to make a fifty-foot version. 

This image illustrates the "blobby" door post bracing (top) and door hardware (bottom.) I am unsure if it's a poor casting or the result of a damaged mold, but it needs to be improved

If you're interested in following along, I urge you to review the clinic pdf file. Over the next couple days, I will post the first of several updates, starting with a thorough writeup of the underframe construction. Watch for that in the coming days.