Another well preserved beauty

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What are those units in #1?
Switches, breakers?
Another great shoot

Well preserved is right! Trumps any industrial spots I've been to.

Very nice! It's rare to see such a clean plant - I've been in a control room that was almost as nice, but the main floor was trashed to hell!

In response to: "What are those units in #1?"

The units in #1 appear to be three phase circuit breakers. I am guessing they are probably rated about 15KV, based on the size of the insulators. I suspect each bay controls some large load like electric motors (pumps) and transformers.

They used colors to identify phases but other than looking pretty I don't think the color coding as seen here serves any great purpose.

Again I am guessing but I suspect the tanks are compressed air accumulators. Most modern "air circuit breakers" of this apparent class use magnetic coils to force the very destructive arc that forms when the contacts separate into arc quenching "arc chutes". Each phase in the picture does have some sort of a vertical brown affair that looks like an exhaust stack. I suspect they spit out a little flame when the breaker opens under heavy load. That leads me to think instead of using magnetic coils to force the arc into arc quenching "arc chutes", the compressed air is the primary arc quenching mechanism and that explains the relatively large size of the accumulators. In other words, a very large blast of air is directed between the contacts when the breaker trips, quenching the arc. This is not an elegant design if my guess is correct. Modern air circuit breakers do use a small mechanical piston, sometimes called a puffer, to direct a small blast of air over the contacts as an assist for low current trips but this function is very different than what I perceive here.

My overall impression of the technology in the picture, including the associated bus work, is that it is very old and very crude. The designs for medium voltage circuit breakers from 75 years ago and more that I have seen are much smaller and more elegant than these things if my guesses are correct.