This same technology (steam jets around the top of the stack) is currently used in petroleum refineries where I worked for the top of their flare stacks. The flare stacks are a safeguard mechanism used to burn off hydrocarbons in the event of an upset in the process system. I always wondered what the steam jets actually did. …maybe, dilution is the solution to pollution??

Bob Parks of the Western Md RHS, with an archive at the Union Bridge, Md. WM station, reports back to me:

They found several "Authority For Expenditure" forms for this smoke-lifter ring project. Form 99-49, dated June 29. 1949, authorizes $16,137 for estimate for Local Committee Case No. 96, to apply these rings to "Classes K2, H9, H9-a, I2, M2, J1 locomotives (coal burners)". A hand-written notation says "20 locos. completed." Other forms are for other applications of this project.

Harry said, "I checked photos and two videos, and there are various locos with the rings, some of the same loco both with and without them. As you can see from the AFE's, there were a lot of classes of locos that these were applied to."