Bombardier Transportation announced its fleet of subway cars for New York City Transit (NYCT) returned to passenger service on Friday, ahead of New York’s early morning rush hour. The cars had been removed from service after two isolated incidents related to the door mechanisms.

Known as the R179s, the cars were approved to return to service after Bombardier completed all work related to verifying the safety of the door systems. The work included the inspection, calibration, and testing of the door locking mechanism, new software upgrades, static and dynamic testing, and all necessary accompanying analytics and documentation.

Bombardier’s root-cause analysis indicated that the two incidents triggering the verification were due to a rare and very specific combination of unforeseen mechanical and operational circumstances that proved extremely difficult to replicate and were unlikely to reoccur. As safety is Bombardier’s utmost priority, the company acted swiftly and decisively to put in place corrective measures on the entire fleet.

“Bombardier stands by the quality and integrity of its railcars and components and wants to reassure customers and passengers that the R179 doors are completely safe,” said Elliot G. (Lee) Sander, president, Americas Region, Bombardier Transportation.

Bombardier reported that since the start of passenger service in January 2018, the R179 cars have accumulated over 10 million miles in operation and are performing well. The company added that the fleet is exceeding the contractual requirements for reliability amid steady improvement in the cars’ performance, as measured by NYCT.