Rotary Converter, IRT Subway Substation 13, Midtown Manhattan, 2017.
All the pixels, no Metrocard required, at https://www.flickr.com/photos/mattblaze/32992380451
#photography
NYC’s IRT subway, opened in 1904, is powered by a 600 volt DC third rail running alongside the tracks. Power is fed to the system via a number of substations throughout the city, where high voltage AC is converted to the lower voltage DC used by trains.
Until recently, this was done with electromechanical rotary converters (essentially a combination AC motor and DC generator). They are now supplanted by solid state rectifiers, but a few of the original rotary converters remain operational.
If you like this stuff, there’s a sadly out of print book, “New York’s Forgotten Substations”, with some excellent photos.
Wonderful photo. I suspect those rotary converters are very reliable!
@[email protected] haha I came to this thread thinking “didn’t they use mercury arc rectifiers, like DC elevators and such?” and learned that they didn’t!
So thanks for that. 😋
@[email protected] those rotary converters were pretty amazing.
@[email protected] I hadn’t had my morning coffee and my first thought when I saw this photo (of the rotary converter) was “oh, that is a top view of a Curta calculator.” (I used to be pretty good on a Curta.)
@[email protected] a very, very large one.

@[email protected] @[email protected] continuing the theme of misunderstanding what you’re seeing, I saw that and was thought it was a clockwork camera lens for a second (not that I think there is such a thing, but my brain isn’t that quick today).
@[email protected] always pleased to see this one come round again on your feed






