MOW Challenge: PRR GPa Ballast / Cinder Hopper

[prr7161]

Many moons ago I bought a pair of Bowser Shadow Key H21as with the idea of turning them into something else in the H21 family, and the GPa cars are a nice kitbash challenge:

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Built around 1905 as coke hoppers, these cars moved into MoW service as ballast and cinder hoppers by the mid-thirties, in which they had a surprisingly long lifespan.  Although they predate the H21, the two designs have a number of common parts.  References for this build will be the Teichmoeller PRR open hopper book plus Bob Chapman's article on an HO project from a 1996 article in Mainline Modeler.

The big task is obviously to rework the lower part of the body and build new side-dump hoppers, as well as shortening the body overall by about 6" and backdating the brake gear.  Partly because the Bowser H21 models put the brake platform in a location that is difficult to remove without damaging the rest of the end (ask me how I know), and partly because cleaning out the sawtooth hoppers will be easier if I can access the middle of the car, I plan to assemble this from two Bowser 'A' ends spliced together on a common lower side and hopper styrene assembly.  I also plan to add interior bracing detail.  Although the Bowser cars ride about a scale 8" high, I don't plan on lowering the car too much, partly for functional reasons and partly because to my eye the extra height just doesn't jump out as a problem.  Finally, the car will be painted in the older "battleship" gray MoW scheme and lettered with Mount Vernon Shops decals.

I'm really putting myself under the gun here to get this done in time to take it to the PRRT&HS Annual Meeting on May 9.  We'll see if I can make it!

[towl1996]

I'm looking forward to following this. I hope you'll take plenty of pics as I would like to follow your lead on this. Interesting car.

[prr7161]

Thanks!  I plan to update weekly, hopefully with some good photos.  I am camera-challenged right now so relying on others for higher-quality pics, but should be able to document everything well enough I think.

just ordered the last parts needed - chains, brake wheels, and rivets - and started scraping and sanding on Monday!

[prr7161]

Here are the first few progress shots, in comparison with the stock H21a.  At this point, the donor cars have been shortened by 8" (2" will come back when the new top flange is added), unneeded side ribs removed, and some of the cast-on grab irons scraped off.  Although the ladder grabs will also need to be replaced, I am leaving them for now for a little extra structure - the ends will be hanging free for a while once the bottom of the sides is shortened.








The major surgery starts today. Both cars will be cut on the far side of the center rib and the hoppers will be removed.

One catch so far is the coupler location.  Bowser put in a drilling dimple for body-mount couplers, but the 905s sit about 1/16" too far back.  The needed location is annoyingly right at the frame and shell seam, so that will have to get styrened over to provide a coupler mounting pad.  I will want to be able to slip the frame out, though, for the brake gear work and for painting, so I will need to keep it unattached until almost the end of the build.

[prr7161]

A few quick'n'dirty cell shots of today's progress:



The splice is right!  No glue yet - the halves are loose to make it easier to do future work.



The other side.  A tiny bit gappy, but some Tamiya putty should fix that.



Hoppers off.  Left a bit rough since most of the rest of the structure here will be going away.  Some care is needed when removing, however, to leave as much of the slope sheet as possible - it will eventually need to be extended down into the new hopper well.

I have a little cleanup work here to do yet - remove the last scraps of paint, putty in the ejector pin marks on the interior of the slope sheet, etc. - but the next big step is to template out the new sideframes.  I would like to have those ready before removing the rest of the old hopper structure since the sections will get structurally weak once the old braces and sideframes are removed. Chapman gives dimensions in his MM article, so I will test these out in paper first.

[prr7161]

Working through the new hopper bottom arrangement this weekend.  Once you get down to it, there isn't a whole lot of the original Bowser plastic left.  With that plus the brittle Bowser plastic that breaks if you look at it sideways, it's getting to the point that it might be easier to just scratchbuild the whole thing.  Gotta sleep on it and then get back to work tomorrow.

[towl1996]

Well, that stinks. It seems to me that etching the sides, like a passenger car, and using the bowser hopper as a core might be a way forward. I don't know if that's within the rules for the challenge, but it may get you the car.

[prr7161]

I think the etch would be great for the ends, actually.  Because of the inset of the sides at the bottom, it's not a direct overlay for the sides, but building them doesn't bother me.  Getting the end ladders and bracing in right is the bugbear (and the Bowser ones snapping like crazy while working on the car is what makes the scratchbuild a better option).  At any rate, I am off on the scratchbuild starting with the frame.  Should be back on track with pics by this weekend.

[prr7161]

A quickie photo of progress - frame, end sills, body bolsters, and one of the lower sides.  So far so good.  Definitely will not be much to look at next week for the convention, but I think it will come together alright in the end.

[prr7161]

Keepin' on keepin' on with this build:



Both lower sides are on, along with end braces and body bolster bottom flanges.  The Bowser Crowns fit great, though I think the FVM low-profile wheels are helping a lot.

Here are a couple of shots for comparison with an H21a:






The model so far is coming in at scale height.  It's designed for MT 905 couplers, so the centerline of the coupler should still be at a good height.  If it needs a little shimming it will still be pretty darn close to scale height above the rails.

[dougnelson]

Looking good!  Bruce loves in-progress models for the model room. See you Thursday in Altoona.