In between other projects tonight, I added another half-turn to the helix.  Figured I might as well enjoy it a bit as well, so ran a quick test train – just one of the SD60Ms (future CRNW 600), a half-dozen ore jennies, and a boxcar that was sitting on my bench anyway.  Figured out that an Atlas SD60M is good for about 20 cars on the 2.5% grade, based on a test I didn’t video.