2 phase, with the phases at 90 degrees was widely used in the early days of electric power. Pockets of it remained in the UK certainly until the 1970s. I think the original Niagara hydro power scheme was 2 phase. A Scott transformer
https://en.wikipedia.org/wiki/Scott-T_transformer is used to connect 2ph and 3ph systems.
DC mains were still common in London in the 1960s. Lift machinery was a major use for DC. I think the printing presses in Fleet Street (the traditional home of newspapers in London) were supplied from DC mains. I can remember my father turning off the DC isolator in his factory building if he was last person out. It supplied the lift and probably nothing else.
I don't know if it's still there, but the lift at Alexandra Palace east tower (the original home of TV broadcasting in the UK) was pretty old when I last used it less than 10 years ago. Manually operated trellis "finger trap" gates. Some nice "clunk" sounds from the controller.