Compressor Cleanout

Frank writes…

Sunday saw the completion of our quick in-house compressor fix-up project on car 18’s National BB2 air compressor.

Thanks to Richard for fixing us up with replacement ring terminals on a new lead, replacing an old one that had been damaged. After that, it was time to flush any remaining old oil out of the pump. This involved putting some diesel into the sump and cycling the pump a few times so that the "slingers" could distribute the diesel around. Then, drain, repeat with a bit of sacrificial compressor oil to get rid of the diesel, drain again, and then finally fill with good compressor oil. Many thanks to Steven (shown above about to unscrew the drain plug), Joel, and Nick for all their help with this! Cycling the compressor on low power was done by hooking it up to a welder. Next up: testing on 600V!

And in other news, Richard spent a while in the 18 working on adjusting the thermostat. The great news is that the thermostat works! After a bit of fiddling, we got it to turn the heat on at about 61 degrees and off at about 70. That's a bit warmer than we'd like, but it's pretty close. Joel is looking for any documentation we have on these Consolidated bi-metal thermostats so we have a better idea of how to adjust ours; anyone have any manuals they can share?

And in other news, Nathan and Mikey were finally - after a lot of percussive effort - able to remove the armatures from the L7, one of our WEPCO steeplecabs. The L7 has been "sort of" out of service for a number of years, ever since its rare (and enormous) CP-19B air compressor went to ground. We've run it a few times coupled to something else that was providing it with air, just to keep away the "sit-itis," but repairing that CP-19B is a big challenge. The compressor won't fit through the cab door, so the guys had to disassemble it in situ.

Curiously, the New York Central S-motors used CP-19B air compressors as built (all were later replaced by more modern types), and I came across this diagram during my research for my article on our S-motor. You'll note that the CP-19B has a dual-armature design with no gearing: both armatures are attached directly to the crankshaft. Sounds kind of like the gearless design of the S-motor itself, but I digress. The above cutaway shows why the armatures are shaped like big basins, with a largely hollow interior.

But that sure doesn't mean they're lightweight! Here, Nathan on the forklift and Mikey directing the action lift one of the armatures onto a pallet. Neither armature had obvious mechanical damage, like holes in the comm or bad arcing, so that's a good sign. We'll examine both and see what the next step toward getting the L7's compressor fixed might be.

ADDENDUM: After writing this, I tried Googling information on CP-19 air compressors and found this link from the University of Wisconsin. A list of TMER&L expenditures includes this entry from 1930: "R-614, purchase of 17 second hand air compressors of the CP-19-B type." That's one year before the L7 was built. And remember how the NYC S-motors had CP-19B's as built? Well, they were all replaced by newer-model air compressors in the 1920s, possibly during a 1929 overhaul of the S-motor fleet. Did the L7's air compressor come out of an S-motor? There's likely no way to know for sure, but it's an interesting thought!