I found, rummaging around in my files, part of a copy of a supplement to RMC from 1979. It lists significant dates for many changes in railroad locomotive and freight car standards. But for some reason, I only have copies of two pages, and it’s incomplete. The freight car information ends about 1927.
If someone has a copy (pdf?) of this that’s complete, I’d like to have it.
But what I’d really like is a similar document with the significant dates like this that might be more comprehensive. I started one for myself a long time ago, but that seems to have disappeared.
What set me looking for this was wanting to know the dates when AB brakes came into existence, and the later-than-that date when K brakes were outlawed in interchange. Yes, I know, that outlaw date was frequently flouted, but still, I’d like to know when the rule called for no more K brakes.