Here’s a good view of what the end of one of these cars looks like:

http://rrpicturearchives.net/showPicture.aspx?id=1251473

While the stock Walthers model basically just has some generic raised-tread pattern on the end, you can see that the pattern of walkway grating is quite distinctive, and I wanted to capture this.

The following wreck photo also highlights quite clearly how the grating is open, and would be see-through:

http://algomacentral.railfan.net/images/AlgoCenRy/AC_Mile_5_wrk-5_5-14-1980.jpg

If I were only doing one of these cars, I might consider completely cutting away the end platforms and rebuilding them from scratch to have the open grating, however for the sheer volume of these cars that I need, I’ve decided this would be far too much time and effort to be worth it.

I do however wish to at least replicate the tread pattern, which is a big difference from the model. To this end, after disassembling the cars and removing the handrail pieces, I filed the top surface of the end platforms smooth to remove the existing tread texture.

End platform filed smooth.

I cut the new walkways out of etched brass walkway/grating material. The walkways are a rectangular “Apex” tread pattern. I’ve been using etched brass material from Details Associates. I just used a regular pair of scissors to cut the thin brass sheet.

There’s two parts to the walkway tread on these cars. There’s the grating on the open area of the platform, and an extra bit of grating leading to the end ladder. The platform grating is cut out of the etched material in a rectangle 2.5 by 10.75 scale feet in size. The cut piece should all be whole rectangles, with the “grain” following the width of the car.

The walkway to the end ladder grabs is oriented perpendicular to the platform grating. With the sizing of the rectangles in the Details Associates etching, I cut a strip from the etched sheet 3 rectangles wide; this is perfectly the size to fit between the platform grating and the car body. I then cut these into approx. 1.75 scale foot pieces.

With all the piece cut, I attached them to the prepared underframe pieces using CA adhesive. Very carefully, trying not to glue my fingers to themselves or the car, I used a toothpick to spread the CA across the bottom surface of the grating, and then applied the grating material to the car. For the smaller pieces I used a pair of curved tweezers to move them into position.

Several finished platforms, with one just filed smooth in the middle.

Completed walkway/platform grating with the underframe and body fitted together, showing how the walkway accesses the end ladder.

This is the current point I’m at with these cars (well, the 9 I’m [semi-]actively working on). 5 cars now have the grating complete (I just finished a few of them up tonight) and another 4 have the platforms filed and prepared (and actually have for quite some time now).

After I finish this current batch of cars, (I’m hoping to try to bring these 9 all the way through to completion now) I’ve got another 50 or so of these Walthers cars waiting for the same treatment at some point!

So in my previous post, I introduced this project and the prototype for these cars, 300 cars built by NSC to an Ortner design in 1974-75. Walthers makes an HO model of the Ortner design, which makes a convenient start to this project. Of course there are some details, both major and minor, that differ between the Walthers model and the AC prototype cars.

Stock Walthers model without the hokey included aggregate load.

The biggest change that needs to happen is that the AC cars have tubular V-bracing between the bays, not the solid bulkheads that the model has. This takes a little bit of work, but is not difficult, and you’ll agree this makes a huge difference in appearance.

If you only want to do minimum changes or detailing to turn the Walthers car into a reasonably accurate AC car, this is the change to make. Also, since the insides of the cars were unpainted steel, this change can be done on a factory painted car while completely preserving the factory lettering, as the inside of the car should be masked and repainted a rusty colour.

The first step is the easiest, just take out the removeable bulkhead pieces and throw them away. (Or, toss them in the scrapbox. A good model railroader is a pack rat; you never know when that oddball useless leftover part now can be repurposed for something completely unintended later. Or at the very least chopped up into smaller pieces or used as part of a steel scrap load or junkyard scene.) Then I fill the holes left behind with modeling putty. Most of the cars I’ve been working on so far I’ve filled the holes using either Tamiya or Squadron putties. Other modelers also recommend Bondo putty from the automotive department, and I’ll probably try that in the future. Canadian Tire is a lot more convenient than the local hobby shops that are an hour+ away.

Several cars in progress.

Once the body putty has had a day to cure, I file it down even with the inside surface of the sides and sand it smooth with progressively finer sandpapers. Once again the automotive aisle at Canadian Tire is rather handy here as a source for 1000+ grit finishing/polishing sandpapers to get a nice smooth interior side.

Smoothing out the bottom of the bays is a bit more tricky with the angled geometries, so I just did the best I could. A sanding stick from the hobby shop gets a good start here.

I used a sanding stick like this one on the inside of the bays.

Now, before I move on to installing the interior bracing, I finish cleaning up the top of the car body. (Or this part can really be done first.) The AC cars have an overhanging lip over the top of the car end that the model doesn’t have. I modeled this simply using an HO scale 2″x6″ styrene strip across the top of the end. First, however, two little angle pieces need to be carved off the top of the corners on the model and filed flush with the top of the end, as indicated in the below photo marked with arrows:

Remove corner detail on top surface at points indicated to allow 2×6 header to be installed.

Once this detail is removed and smoothed down, the end cap is installed. I simply cut a piece of styrene 2×6 to length and cement it to the top of the edge. Once the end cap has been installed and the cement has set, I file down the angled top chord on the model flush all the way around with the top of the 2×6 end cap.

End cap installed. End handgrabs are partially installed on this car.

Once the sides are finished, the interior bracing can be installed.

I made the braces from .040″ brass rod/wire. The rod is cut to length (approx. 1.20″) and I file one end off at an acute angle so that it rests properly against the side. Test fit this several times before glueing in place.

I drilled a small hole right next the the centre sill of the car between the bays to accept the bottom end of the brace. Then I simply use a drop of CA glue to secure both ends of the brace.

Interior bracing.