on Mon Oct 18 03:11:32 2021, in response to Re: What exactly IS SMEE?, posted by Train Dude on Sun Oct 17 09:31:25 2021.
I have several instruction manuals from WABCO and the last E was for "ELECTRIC" not emergency. As I mentioned there is (or was) a brake system called SME which had the emergency valve but lacked the electric. A similar situation existed between the AMUE brake system with the ME-23 brake valve and the AMU brake system as used on the Chicago 4000 series rapid transit cars, NYCRR prewar MUs and North Shore interurbans with M-23 brake valves. The last "E" was always for the electric since not all brake systems had that feature so it was an add on.