Reference pages

Thursday, November 10, 2022

Heavyweight sleepers, conclusion

I have been describing a conversion of an AHM (Rivarossi) heavyweight Pullman sleeper, from its original 12-1 configuration (12 sections, 1 drawing room) to a 10-1-1 floor plan (10 sections, 1 compartment, 1 drawing room). In the last post about the project, I showed completion of the roof with its air-conditioning ducts (it’s here: https://modelingthesp.blogspot.com/2022/10/heavyweight-sleepers-part-3-roof.html ).

Now only completion of the car remains. I’ll begin with trucks. The AHM trucks are a decent representation of the prototype truck used by Pullman, what they called “Style 2411A,” so their appearance is all right. But there are some operational problems that do need to be corrected. The photo below shows them (the trucks shown are lightweight-car four-wheel trucks, but the principles are the same). The photo is a repeat from an earlier post (see it at: https://modelingthesp.blogspot.com/2021/04/modeling-sp-passsenger-cars-part-10.html ).

First of all, the Talgo-like coupler tongue, shown above at left, is molded with a horn-hook coupler. These are, of course, grossly poor in having not even a ghost of prototype appearance, but also problematic in that they don’t behave well if the car has to be pushed instead of pulled at any point. 

My solution is to cut off the horn-hook and drill and tap the tongue for a 2-56 screw (center). Then the Kadee box is attached with a flat-head screw (arrangement at right in the photo). This is the ideal arrangement: a Kadee coupler in its own box. I recommend a flat-head or pan-head screw for clearance under the diaphragm.

Note also in the photo above the AHM wheelsets. They comprise half-sets, a wheel and half an axle each, connected with an internal steel rod. The good news about this arrangement is that it is easy to correct an out-of-gauge wheelset; the bad news is that the wheelsets are free to get out of gauge. And the flanges are oversize. 

I often replace AHM wheelsets with Kadee wheelsets. Prototype passenger cars normally used 36-inch wheels, while classic-era freight wheels, like the Kadee ones, are 33 inches in diameter. But the original AHM wheels are also 33-inch size, so to keep the coupler tongue at the correct height, using freight wheelsets is in fact the correct answer. And of course you get better flanges.

I should also mention the attachment of the AHM Pullman trucks. It’s a friction pin, which can work well when new, but inevitably gives trouble after some time in service. As I have mentioned for the AHM lightweight cars, the simplest solution is to drill out the pin attachment holes with a No. 30 drill, glue in a short length of 1/8-inch styrene tubing (Evergreen No. 224), tap for 2-56, and then use a screw of that thread to attach the trucks.

I have used a remarkable variety of diaphragms on my model passenger cars over the years, including a variety of home-made ones (to see examples, you can use “diaphragm” as the search term in the search box at upper right of this post). For the Lake Merritt, I combined a diaphragm folds from one in the scrapbox, with a new striker plate. I also replaced the poor AHM brake wheel with a brass Cal Scale one.

That completed the project. You can note in the photo above that both the roof and the diaphragm striker plate are weathered. This was done with my usual method based on acrylic washes. Most railroads washed their passengers cars fairly regularly, but that wash only involved the car sides, not roof or ends, so those areas should certainly show some dirt. Here’s the final product, shown on my layout.

This was a fun addition to my fleet of heavyweight passenger cars, and probably concludes my conversions of the old AHM cars to different floor plans. I have enjoyed doing them all, but likely already roster more such cars than are needed on my present layout, so I don’t expect to do any more.

Tony Thompson

No comments:

Post a Comment