A Subway Ventilator

Put this in the “can’t leave well enough alone” category. I took the picture above because I thought it was visually interesting. It’s a ventilator at the Astor Place station on the Lexington Avenue line, which means it’s part of the original 1904 subway. (Obviously, it’s been rehabbed since – you can see repairs to the beams holding up the grating in the second picture below – but this is part of the original design.)

So I took the picture. And then I noticed people walking over it, but I had moved by then, so of course the next picture does get someone’s shadow but doesn’t match the angle:

The line of fluorescent lights is more or less the edge of the platform, with the grating over the tracks.

Then I started thinking about why you so rarely see someone’s shadow like this when you’re in a station. Most of the underground portion of the system was built cut-and-cover and so is quite shallow. Because (a) the lines generally follow streets, (b) local stations (which are about 80% of the stations) have platforms at the outer edges of the width of the rail right-of-way, and (c) ventilators are always located in sidewalks and never in the driving right-of-way, the ventilators are usually over the platforms. If the ventilators were over the platforms and consisted, like this one, of just grating supported on the roof beams, then (a) precipitation would fall directly on people when they’re on the platform (which happens all the time at above-ground stations but seems particularly dirty when discussing an underground station), (b) garbage could fall directly on people when they’re on the platform (which is particularly dirty), and (c) people could look directly up at pedestrians (which may or may not be dirty, but is definitely a bad idea). So the typical ventilator is a linear box, with grating at the top, a solid bottom, and an open side either facing the tracks or the side wall. Air can move back and forth, but no one can see up or down and nothing falling from above hits the people below. At Astor Place, there’s a big island in the middle of the Y intersection as Fourth Avenue and Lafayette Street merge together, and that’s over the tracks, which is why there is a non-standard ventilator here.

This train of thought took just about the time it took for my train to arrive, and probably in its broad outline matches what some designer thought about 120 years ago when deciding how to get air into the stations.

The moral of the story is that carrying a camera around all the time has a tendency to send me down design-related rabbit holes.