An Inside Look at the Subway’s Archaic Signal System

The New York Times [no paywall]: “Deep inside a subway station in Brooklyn, in a cramped, industrial room, Dyanesha Pryor pushes in a metal lever on a hulking machine that was installed nearly a century ago. A few hundred feet away, a signal light flashes red and a train that had been rumbling down the local tracks slides to a stop. Ms. Pryor, a transit worker, pulls another lever and a section of rail shifts into place, allowing the local train to merge onto a shared track in front of a waiting express train. She then restores the signal to green and the local rolls into the station. Ms. Pryor repeats this sequence — punctuated by the clank, clank, clank of the levers slamming into place — dozens of times over the course of the day in the hidden control room at the Hoyt-Schermerhorn station. Thousands of subway riders a day depend on Ms. Pryor for a smooth commute. But if she has to unexpectedly step away, even for a bathroom break, all express service is rerouted to the local tracks until she returns. “Everybody has to go local because there’s nobody here to move the levers,” said Ms. Pryor, 35. About 85 percent of New York City’s subway system still operates with this analog signal system. The outdated equipment is no longer manufactured and has to be manually operated, around the clock. It’s no surprise then that the system is a leading cause of delays. Over the past 15 months, it has led to an average of nearly 4,000 train delays a month, according to data from the Metropolitan Transportation Authority, the state agency that runs the city’s transit system. The subway has long depended on “fixed block” signaling, a method of maintaining safe distances between trains that uses track circuits to detect the location of trains, wayside signals similar to traffic lights and mechanical trips to stop trains that pass a red light…”