The computer glitch preliminarily blamed for Friday’s rush-hour subway meltdown marked the latest — and worst — example of persistent problems with the system, THE CITY has learned.

Internal MTA incident reports obtained by THE CITY reveal that transit officials flagged Automatic Train Supervision system failures for subway problems at least 13 times since last month alone, contributing to more than 300 train delays on the numbered lines.

For nearly 90 minutes Friday, service on the Number 1, 2, 3, 4, 5 and 6 lines and the 42nd Street Shuttle got snagged when Automatic Train Supervision and its backup system failed during a sweltering evening commute, transit officials said.

“The people in my subway car said they had been sitting there for an hour,” said Armenoush Aslanian-Persico, 33, who walked into a stalled No. 2 train at Chambers St. on her way to The Bronx. “Some people were frustrated, but it looked like the true New Yorkers kind of expected this and were just trying to get through it.”

The Automatic Train Supervision system, which controls train signals and switches on most of the numbered lines, is monitored at New York City Transit’s Rail Control Center in Manhattan. When the system fails, trains can no longer be automatically routed, leaving the Rail Control Center largely in the dark.

“This could not have happened at a worse time,” Andy Byford, president of New York City Transit, said Friday.

Update: Subway service remains suspended on the 1/2/3, 4/5/6, and 42 St Shuttle trains.



We are working as fast as possible to resolve an issue affecting the computer system that controls our signaling system.



We recommend the lettered lines or local bus service. (1/4) pic.twitter.com/POKrCl5Fxr — NYCT Subway. Stay Home. Stop the Spread. (@NYCTSubway) July 19, 2019

The Worst, but Not the First

According to the incident reports obtained by THE CITY, Automatic Train Supervision has been pinpointed as a “trouble cause” for incidents with various impact on subway service going back months.

An MTA spokesperson told THE CITY there have been two “significant” interruptions of Automatic Train Supervision in 2019 — during Friday’s evening rush and on March 21-22. The spokesperson said those events involved different computer servers.

But there have been several other incidents connected to the system.

A July 8 report noted that Automatic Train Supervision failure at the 138th Street – Grand Concourse station in the Bronx delayed northbound service on the No. 5 line just before 7 a.m. A day earlier, shortly after midnight, the system was cited for “a loss of scan” on the No. 2 and No. 3 express track between the Wall Street and Chambers Street stops.

And on Saturday, July 6 — as on Friday — the 42nd Street Shuttle and all the numbered lines except for the No. 7 encountered delays once the Rail Control Center status board “went red.” That affected service from 10:22 a.m. until 12:05 p.m., and delayed 61 trains, according to an incident report.

Byford noted the similarities during a Friday night news conference.

“Effectively, I am rolling these two incidents into one to identify why it is that we’ve suffered this apparently similar incident,” he said. “We will get to the bottom of that.”

Friday’s meltdown began at 5:50 p.m., the incident report says, when “Rail Control Center was unable to see any trains.” Service began being restored around 7:15 p.m., but not before wreaking a huge ripple effect across much of the subway system during the start of a heat wave.

An incident report shows the computer failure caused 134 service changes on the No. 1, 2, 3, 4, 5 and 6 lines, though Byford said “some sections” of the lines in The Bronx that continued operating. With many riders shifting onto other lines, 93 trains ran late on the A, B, C, E, F, N and R lines, according to the incident report.

‘Sitting There Stewing’

During the outage, transit managers scrambled to staff towers in the subway system from which operators can manually operate signals and switches — as crews do on all lettered lines except for the L — to get the numbered trains safely moving.

The L and the No. 7 are the only lines equipped with a modern signal system known as Communications Based Train Control. MTA figures show they had the best weekday on-time performance of all subway lines in the system: 94.3% for the L and 90.2% on the 7, whose signal upgrade was completed this spring.

While subway performance statistics have been on the upswing since last year, a service disruption on a night when temperatures topped 90 degrees left riders steamed.

Being trapped in a hot subway car in the tunnel for a half hour, followed by having to ride 5 different lines to get to your destination due to a whole host of nyc subway technical errors is enough to make a girl believe in this whole mercury retrograde business. — Gabriella Ziccarelli (@IPwithGZ) July 20, 2019

“We were sitting there stewing,” said Gabriella Ziccarelli, 30, whose 6 train commute to the Upper East Side stalled between the 23rd and 28th Street stops, “This poor lady next to me had her frozen groceries just melting.”

Ziccarelli said she tried to switch to the R or W lines at 28th St., to eventually connect to the Q. But she said trains were packed.

“It was just a comedy of errors trying to find my way home,” she said. “I definitely missed the dinner I had planned.”

The Friday night subway problems spurred the Riders Alliance advocacy group to call on anyone caught in the chaotic commute to join a “Fix the Subway” rally before Monday’s MTA committee meetings.

“Unless we upgrade and maintain our technology, we can expect the things that happened in the subway [Friday] night to happen more frequently,” said Danny Pearlstein of Riders Alliance.

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