Need help on "era" information

[Loco Bill Canelos]

A few years ago I saw a listing of major changes in railroad equipment and the year it happened, it was in an old magazine, possibly MR or Trains.  It listed things like changes in air brake equipment, when roofwalks were no longer required, when "COTS"abels were applied and many other major changes.  I kept a copy and now can't find it. 

Can anyone point me to that document, or any similar source??

Thanks Bill

[Skarloey Railway]

This might have what you want
http://www.hosam.com/grd/dates.html
only goes up to 1996 but looks pretty comprehensive
Colin

[Ken G Price]

Colin, thanks for the list. Very interesting read.

[Loco Bill Canelos]

Colin, A huge  thanks for this info, While it is not the one I saw it is just perfect for what I need!!

Sorry I failed to thank you sooner.

Bill

[Skarloey Railway]

Google is my friend!
Glad it does what you want
Colin