It was the mid sixties when I first started riding the subway with my folks. Back then, the three divisions had much more distinctive identities in their rolling stock, stations, signs and even entrances.
Prior to 1968 and the emergence of the R-40s, I pretty much knew:
-An IND train would either be black and groaning, or blue-and-white and extremely noisy. Either way, they would have those pronounced eaves on the roofs. When we rode the IND, it was mostly from Jackson Heights to Manhattan, so we would only see the then-very shiny R-32s along 6th Avenue on the 'D'. Most damning, an IND train never seemed to go outside.
-A BMT train would have the rounded roof, and the 'baloney-colored' seats found on the R-27s that we always changed for from the Flushing line at Queensboro Plaza. Very early on, I recall hearing BMT trains departing the Plaza making the same groaning sounds I associated with the 1-9s. Apparently, there still were Standards going to Astoria well into the sixties.
Trains could be found in a variety of colors: Light blue and white on the R10s and WFs; black on the R1-9s; black or red on the R-27s; and that strange gold on the 32s and 38s. Mainline IRT cars could be black, red or dark green. This variety would end in the seventies, falling victim to graffitti and the MTA's penchant for making everything silver and blue.
Station guide signs also varied by division. The IRT signs were usually white letters on a dark blue or black background, with plenty of wordy information on destinations and lines you could change to further down the line. Well into the eighties, there was a sign on the stairs ascending from street to mezzanine at 111th/Roosevelt that referred to the 2nd Avenue Line. BMT signs were usually white letters on a green background, with the BMT letters often bright red. Similarly descriptive information was found.
Most IND entrances had square globes with the old 'modern' MTA logo. IRT entrances looked very skeletal, with those vertical "SUBWAY" signs. BMT entrances were very ornate, with much detail above the stairwells. Somehow the heavy rivet work reminded me of battleships. Some of these survive along 4th Avenue in Bay Ridge.
Of course, the IRT and BMT stations had the elaborate mosiacs, which we're all delighted to see return either in their original forms, or by careful reproduction.
In the seventies, I was able to ride the trains myself. By then, the new, complex route coloring system was in effect, and many of the distinctive IRT and BMT island platform signs were replaced with the now familiar black letters on white background. I had a ball checking out all the different types of rolling stock to be found on individual lines (up to six on the 'E' and 'F'), but it always seemed that the hotter it was, the fewer trains with air conditioning there would be.
I only was able to ride the Myrtle El once, on a farewell fan trip in October 1969. Maybe some of you were on it? I did the remaining Bronx portion of the 3rd Avenue El in one direction only around 1970, and didn't even know it was closing down until it was too late. The Culver shuttle also went out with a whimper.
Yes, there was no air-conditioning, so windows were left open in warm window, making conversation impossible. I don't remember there being any station or connection announcements on any line other than the Flushing.
I remember being terrifed to read how various politicians wanted to replace all els with underground subways. Happily, in the year 2000 we still have many miles of active els in all four boroughs- even Manhattan! (Despite popular misconception, the outside stretch of IRT from Dyckman to 225th is NOT the Bronx!!)
The best part of our subway childhoods? The railfan window, no doubt! Large chunks of the system can no longer be viewed from this window. Sad, but true.