The MTA pulled its newest subway cars out of service early Wednesday for the second time this year after two train cars disconnected on the tracks overnight.

The uncoupling of an A train making its last run of the night occurred shortly after 1 a.m. at the Chambers Street station in Lower Manhattan — the latest safety failure on subway cars that only began coming into service in November 2017. 

“I heard the whole train brake really loudly and all the lights turned off,” said Hupaul Camacho, 26, who was on his way from Brooklyn to his job at UPS when the train split. “It was loud enough to know it wasn’t like a normal brake.”

And the scare comes days before the MTA’s planned return to full service on the subway, which has been limited since March because of the coronavirus pandemic. 

THE CITY reported in November that the R179 subway cars were breaking down more frequently than some older models that had been running for decades. 

A subway car detached at the Chambers Street station early Wednesday, forcing the MTA to take entire line of R179 trains off the rails, June 3, 2020. Credit: Courtesy of Hupaul Camacho

In January, all of the new cars were yanked out of service for nearly three weeks after doors on a pair of R179s failed to function, including one incident in which doors popped open about four inches while a train was in motion. They returned to service after third-party inspections by an engineering firm and assurances from Canadian manufacturer Bombardier that the cars were safe.

The repeated problems with the $600 million purchase — whose delivery was late — led Bombardier to give the MTA 18 additional cars at a deep discount from the original 300-car order.

“This marks the latest unacceptable issue with one of Bombardier’s R179 cars,” said Sarah Feinberg, interim president of New York City Transit. “Customer and employee safety is New York City Transit’s North Star. We will not compromise one inch on safety.”

According to internal reports obtained by THE CITY, there have been 32 incidents involving R179 cars since November 2017, when they began encountering problems soon after they began being tested on the tracks. Those have ranged from door trouble to stuck brakes to motor power issues.

‘It’s Very Serious’

The latest problem occurred at 1:12 a.m. Wednesday, according to an incident report that said the emergency brakes on a northbound A train were activated by an “undesired uncoupling” as the train entered Chambers Street. 

No injuries were reported, the MTA said, when the sixth and seventh cars on a 10-car train became separated.

“At this time, we believe this to be an isolated incident,” Feinberg said. “However, I am launching a full investigation, and out of an abundance of caution, the entire R179 fleet is being pulled from service until further notice.”

In April, the latest month for which there are figures, the R179 cars had a 12-month average of mechanical failures every 150,214 miles, according to the MTA. Systemwide, the nearly 6,700 cars in the MTA fleet had mechanical failures every 131,627 miles.

Bombardier spokesperson Maryanne Roberts said “the root cause of the incident is being investigated by all stakeholders.”

She added, “We are working in collaboration with New York City Transit and Wabtec, the supplier of the link bar between the cars, to conduct a detailed analysis and to implement an inspection plan for the entire R179 fleet.”

The company previously pinned the door problems on Kangni, the door-system supplier. The R179 cars run on the A, C, J and Z lines.

Until the latest problem, 264 of the agency’s 318 R179 fleet had been in service. They were pulled within hours of the uncoupling, according to spokesperson Meredith Daniels, who added that the agency has enough spare cars that it won’t need to move older units from its yards back into service.

According to an incident report, the pull-apart on the A train caused 27 service changes at a time when the MTA was going into its daily 1 a.m. to 5 a.m. shutdown.

“I was lucky to be on the front part of the train that was partially in the station,”  Camacho said. “There were other people stuck in the back of the train.”

The MTA said 10 passengers were safely evacuated from the train.

“An undesired uncoupling is an alarming occurrence,” said Eric Loegel, the Transport Workers Union Local 100 representative for train operators, conductors and tower operators. “It’s not something that happens very frequently, but when it does, it’s very serious.”