The extra funds are needed to get the delayed project back on track, T officials told the agency’s board of directors, which approved the new agreement. The T was supposed to have all 404 new cars it purchased for about $871 million by last September. To date, the T has received only 130 cars from CRRC.

Amid severe delivery delays over the past year, the T looked at scrapping the CRRC deal and ordering cars from another company, but ultimately decided the new agreement with CRRC would deliver the cars faster, T general manager Phillip Eng said. Without the new deal, Eng said, the T would not receive the last car until 2029 at the earliest.

“This is the best way to get reliable cars for the riders we’ve promised to provide a better trip,” said Eng in an interview. “These cars are essential.”

Eng said the deliveries were hampered first by tariffs imposed by the Trump administration on rail car equipment imported from China, and then by the pandemic.

The project has also been plagued by “chronic quality issues,” according to a letter the T’s deputy director of vehicle engineering, Mark DeVitto, sent the company in late 2022. DeVitto outlined 16 failures, including incomplete inspections and reports of parts that are damaged or ill-fitting. Several former workers at CRRC’s Springfield factory, which began production in 2018, interviewed by the Globe last year described a chaotic and often harrowing environment prone to mishaps and delays long before the pandemic began.

A battery explosion, derailment, loose brake bolts, and electrical arcing have forced the T to repeatedly pull the new cars out of service and rely on faulty old cars.

Eng said the quality of the new cars has improved significantly over the past year and is confident the new deal will get the project over the finish line.

Under the new agreement, the T will pay $95 million to reimburse CRRC for increased expenses for parts from its vendors, $55 million to cover tariffs the company incurred since the contract was initially signed and increases in international shipping costs as well as factory operating costs, and $10 million in incentives for CRRC to stick to the new delivery deadline. The T will also agree to waive $38 million in late fees incurred by CRRC if the company is able to meet the 2027 deadline.

Under the new agreement, some wiring work on the cars will happen in China before the cars arrive at the Springfield factory, according to Jeffrey Cook, the T’s chief procurement and contracts administration officer. The agreement protects all jobs at the Springfield facility, Cook said, and gives the T the right to purchase the Springfield factory if CRRC sells it.

In 2019, the federal government banned transit agencies from using federal funding to buy railcars from Chinese-owned companies, essentially limiting any further work CRRC can get in the United States beyond its current deals with the T and transit agencies in Philadelphia, Los Angeles, and Chicago, said deputy general manager Jeffrey Gonneville.

Bao Yujun, deputy general manager at CRRC Changchun, said the new Red and Orange Line cars are the company’s highest priority.

“We understand the MBTA’s urgency to introduce more vehicles into service and we are committed and prepared to implement new and innovative processes to deliver subway cars as scheduled and of the highest quality,” he said in a statement.

Stacy Thompson, executive director of LivableStreets Alliance, a public transit advocacy group, said the new deal with CRRC is “disappointing.”

“This is not an isolated incident, it is indicative of a larger pattern of mismanagement of large procurement contracts,” Thompson said. “I hope this is a wakeup call that the governor and the T will be taking a closer look at similar contacts, especially the fare transformation project, which is also hundreds of millions of dollars over budget and years delayed.”

Jarred Johnson, executive director of TransitMatters, said the new agreement “shows the downsides of an underfunded state agency that has to take a deliberately under-market bid.”

Ten years ago when the T was evaluating proposals from four rail car manufacturers to build the new cars, the Orange Line cars and oldest Red Line cars were desperately in need of replacement. Baked into the request for proposals was a requirement the cars be built in Massachusetts.

The MBTA’s pick for the job, the Chinese company now called CRRC, had never built a factory, trained a workforce, or assembled a train car in the United States before. But the company, one of the largest railcar manufacturers in the world, bid nearly $200 million below the MBTA’s own estimate for the project, and $514 million below the most expensive bidder.

In 2014, the T agreed to pay CRRC $567 million for 152 new Orange Line cars and 132 new Red Line cars.

The agreement included special protections to mitigate the risks of dealing with a company so inexperienced in the US market, according to a summary of the CRRC contract prepared by T staff at the time. That included terms allowing the T to “take legal action to address schedule slippage” and charge CRRC $500 per day for delays.

In 2017, the T agreed to pay CRRC $250 million for an additional 120 Red Line cars and $56 million in change order fees, bringing the total cost of the contract for 404 new cars to about $871 million.

At the time, the T said the new cars would allow for train service every three minutes on the Red Line.

By the time COVID-19 hit China in late 2019, CRRC was already months behind on its delivery schedule. The restrictions that swept the globe in the months that followed only made it harder to catch up.

Ten years after the signing of the original contract, there’s been some progress: the T has removed all its old Orange Line cars from service and is now using only new cars on the line. But the oldest Red Line cars built in the 1960s and meant to retire decades ago are still carrying passengers.

The cost per car under the new agreement with CRRC is about $2.5 million, or about as much as the second-lowest bid for the original contract and close to the T’s estimate for the minimum cost of the project in 2014.

Looking ahead, Eng said he wants to change how the T buys new train cars so that the agency is procuring them more often.

Last year the T estimated that more than half of its vehicles need repair or replacement.