The New York Subway Still Runs On Analog Technology From The 1930s

Upgrading it is slow and expensive work, but the new systems will eventually allow more trains to run on the same track.

The New York subway is old. You see the signs every time you ride it. The paint on the cast iron pillars is layered like the rings of a tree trunk, and if you removed the ads from the walls, the stations would fool any time-traveler from the 1950s into thinking they were still in their own time.


While the physical infrastructure is clearly ancient, you might be surprised to learn that so is the technology. The system that runs the subway and controls the cars is the same that was used 80 years ago. Literally. The indication panels that show controllers where the trains are located date from the 1930s, as do many of the electromagnetic relays that control the lines. Some of these relays are original installations, untouched and still running today, with hand-written seals dated 1952. Take a look at this 1949 video from the New York Transit Museum Archives, which, when it’s not trying to shame passengers into complying with the rules, is full of great info and footage.

Most of what you just saw, from the blinky-lighted indication panels to the relays and even the pop-up levers that can trigger the brakes of subway cars passing over them, are still in use. A repairperson from the 1949 subway could go to work on today’s subway with little additional training. Even the logs are still kept by hand, with pencil and paper.

As you’d expect, this system is expensive to maintain and run. The subway keeps a signal shop which can repair anything in the system, which is essential as none of the equipment is sold or even supported today. Wynton Habersham, VP and chief of service delivery for the subway department, says that when a part of the network is upgraded, old parts are scavenged to be used as spares.

Now the New York subway is upgrading at last, replacing these increasingly unreliable analog systems with something called CBTC, or Communication-Based Train Control. This uses track-mounted transponders that communicate with antennae under every car to let the control room know its speed, direction and position on the line. Amazingly, the subway has run until now without knowing any of these data. This information lets trains be run closer together, and therefore more trains can run on a line at the same time.


It’s slow and expensive work (and is costing billions of dollars), but the result, according to this MTA propaganda film, will be a faster and more reliable subway that’s cheaper to run and maintain.

It’s a shame, though, to see these beautiful old machines being retired. Then again, maybe if you’re hurtling through dark tunnels in a passenger-packed metal tube, you’ll take a less romantic view of the old cloth-covered, fire-sensitive wiring that tells your driver when to stop and go.

About the author

Previously found writing at, Cult of Mac and Straight No filter.