When did the EMD MU connector change? Could you hook up FTs, F3s and F7s? The FTs would be of course the passenger geared and painted units. I remember the IC mixing Geeps and Fs on quite a few freights. I've a couple of pictures in books of C&NW Es and Fs together.
I think what's important to remember is that it's era, manufacturer model and railroad specific. MU connections as supplied by the builder are one thing, if the railroad got fed up enough with it they'd change it. So what 'was' and 'did' is often different from what 'could' if they wanted to. I know I was stunned to find out that SD24's built by EMD couldn't be MU'd with GP7's built by EMD, at least on the ATSF. And it's not like the cables wouldn't 'fit', it's that the sanders and dynamic brake pins (and maybe more) were different. The only units I know that seemed to resist any and all attempts to MU with anything else was Baldwin because of the air-controlled MU rather than electrical. Probably as soon as I post this I'll get evidence to refute it, but hey, that will be interesting to learn too.
Your right, Early Baldwins had air controlled MU (A Westinghouse system) .They could not MU with ANYTHING except other Baldwins. The air MU went away before long. Air leaks in the hoses limited the number of locomotives that could be MU'ed and a severe airleak would disable the consist. It didn't last long, later Baldwins had electric (Sprague) MU. Randy
I recall seeing a photo somewhere of a PA and a FM Erie-build together on a train. For some reason, i always thought that PA/PB's did well in the mountains by virtue of their hefty GE traction motors?
The photo in the book only shows one Erie-Built and the PB and going by the weathering on the pilot and other details appears to have been taken at a different time, indicating that the Erie-Builts and PAs ran together more than a one off instance when a photographer happened to be there.
So I know know that the PA/F unit combo won't work, what about a F7ABB teamed with a chicken wire F3A? I know the SF rebuilt there F3's at some point to look like a F7 but before the rebuilding took place would they have run together? Kevin
