Kitbashing Bachmann 2-6-0 Alco into CNR

[doctorwayne]

.....as it looked under CNR management :
http://www.cnrphotos.com/gallery2/main.p...emId=64733


.....Here's the preliminary modification specifications drawn over Gene's side shot of his own 2-6-0.



Questions:

At this point, I’m not sure about my piping rerouting. Feels like somethings wrong. Also, what would be the piping on the other side? There’s also a tank, but no pump…

This looks like a promising conversion, Matt, but you're right about the piping.

In the photo of the 89, the water line from the tender loops up behind the air tank, then enters the cab through the floor - you can see it through the opening in the door on the front of the cab. That's the injector, which sends the water through the large pipe (just below the handrail) which comes out the front of the cab. It passes behind the top part of the air pump, then drops down towards the running board, terminating at the check valve (which allows the water to enter the boiler). The vertical pipe in front of the cab is a condensate line (drain) from the injector, and it likely also comes through the front of the cab, with that portion of it perhaps hidden by the pipe leading to the check valve. It goes through the running board, ducks behind the air tank, then curves forward and then downward, terminating just above the rail.
The air compressor piping is partially correct, with the steam line to power it coming through the boiler lagging between the cab front and the compressor, just below the pipe to the check valve. (The top portion is the steam-driven pump which does the compressing, while the actual compressing takes place in the lower portion). The steam exhaust line from the compressor does exit from the front of the upper portion, as you show, but the pipe should extend all the way to the smokebox, where it enters, allowing the steam to be expelled up the stack.
On the lower part of the pump, you'll notice the cannister just below the running board and to the rear of the pump: this is the air intake for the pump, and is basically a filter to remove the "lumps". A pipe leads from it directly to the compressor. (Ignore the pipe to the air tank for now - we'll get to it later.) The compressed air exits the pump through a pipe at the front, then drops down through the running board. It's difficult to tell from the photo, but there may be a horizontal loop of pipe attached to the underside off the running board (rather than the more noticeable vertical loop usually used). In either case, this is a radiator (cooling coil) used to cool the air, which gains heat as it's compressed. This pipe then comes back up through the running board just aft of the exhaust pipe from the cylinder, then goes up and over the smokebox, back down the other side and through the running board again.




It then passes through another cooling coil and then (possibly) into the air tank beneath the engineer's side of the cab. Another pipe will exit that tank and cross back over to the other side of the loco, entering the air tank on the fireman's side through the pipe mentioned earlier. The whole idea behind all this piping is to cool the compressed air as much as possible before it reaches the tanks. If the air was put directly into the tanks, and allowed to cool (and contract) on its own, it could give a false pressure indication. One source shows a minimum requirement of 75' of pipe between the compressor and the air reservoirs.

The photo of #89 shows a single phase air pump, while the sketch indicates a cross-compound pump - basically a two-stage pump with a low- and high pressure side, but both types are piped more-or-less the same.

I'm sure that your re-working of this loco will turn out just as well as all of the previous ones, Matt.

Wayne