An MBTA Red Line train at Park Street Station.

THE MBTA DECIDED on Monday to replace all of the older Red Line cars in its fleet rather than just a portion of them, a move that is expected to dramatically increase the number of trains that can operate each hour when all the cars are in service eight years from now and yield savings on future repairs and maintenance.

The purchase means the T will end up with one style of car for both the Orange and Red Lines and one style of car for the Blue Line. Only the Green Line will continue to use multiple types of cars. Officials said the standardization, and the technological improvements that will accompany the new cars, will make it possible to reduce the interval between Red Line trains to 3 minutes instead of the current 4.5 to 5 minutes, which will allow the line to carry 30,000 more passengers per hour. The standardization will also make it much easier for the T to repair and maintain the Red Line fleet.

T officials said they will purchase at least 120 and possibly 134 additional Red Line cars, on top of the 132 already ordered. The contracted price is $249 million for 120 cars, plus spare parts and technical support for the vehicles for five years. With other costs included, the total value of the contract will come to $280 million. All of the cars will be manufactured by the Chinese firm CRRC at a Springfield plant currently under construction.

The additional vehicles are expected to cost $1.85 million apiece, roughly $40,000 below the per-vehicle price of the original order and about $300,000 less per vehicle than what the T estimated it would have cost to do an overhaul of the Red Line cars not covered in the original order. T officials said those cars went into service in 1993, and will require about $36.46 million of work to help them last until 2024.

Beyond the cost savings, the new purchase order will allow the T to standardize its repair operations for Red and Orange Line vehicles, give a financial boost to the CRRC plant in Springfield, and leave the T with a fleet of modern Red Line cars that will last 30 years, almost three times longer than the rehabbed cars would have lasted.

“Why wouldn’t we do this?” asked Braintree Mayor Joseph Sullivan, a member of the state Transportation Board who sat in on the meeting of the T’s Fiscal Management and Control Board. “When someone looks at this, they’ll say it’s a no-brainer. In fact, it’s a lot of brains.” Braintree is located at the terminus of one of the Red Line’s southern branches.

The MBTA ordered 152 Orange Line cars and 134 Red Line cars from CRRC in October 2014, agreeing  to pay $565 million for vehicles that are scheduled to arrive from late 2019 through June 2022. The purchase replaced the existing Orange Line cars and also added extra Orange Line vehicles that could be cycled into service when the fleet undergoes regular maintenance.  The Red Line purchase replaced all but 86 of that line’s cars (84 of which are operational); those vehicles were scheduled to undergo a major overhaul.

In September, MBTA Chief Operating Office Jeff Gonneville suggested service on the Red Line could be improved dramatically if all the Red Line cars were replaced. Over the last three months, T officials negotiated a deal with CRRC for 120 additional cars, enough to replace the remaining Red Line cars and provide extras that can be cycled into service during regular maintenance.

Transportation Secretary Stephanie Pollack called the original decision not to replace the entire Red Line fleet a mistake. She said the Red Line is vital to the region in part because it handles so much passenger traffic and takes riders to the region’s life sciences centers of Kendall Square and South Station, which is close to Boston’s Seaport District. She hailed the decision to negotiate and finance the purchase of the additional cars in a span of just 90 days, suggesting the quick action was a sign of a new mentality at the T.

“It represents what we’ve been trying to do at the T – a different way of thinking, a different way of acting,” she said. “It represents an important difference between the new T that we have been working hard to build…and the old approach.”

Asked if she was criticizing the Patrick administration, which negotiated the original Red Line deal, she said she wasn’t. “I mean the old way over decades,” she said. “The T’s capital investment strategy was driven by resources and short-term thinking and less about long-term strategic thinking.”

The money for the initial $58.8 million downpayment on the additional cars will come out of existing capital on hand at the T. The rest will be borrowed, but T officials noted they had already planned to borrow money to finance the planned overhaul of the remaining cars. In the end, the T will end up spending more than it would have with the overhaul, but it will also have many more vehicles, and new ones at that.

The primary concern now is that the T is counting on CRRC to deliver the Orange and Red Line vehicles on time and on budget. In winning its initial contract, the Chinese company underbid its closest rival by $154 million. Other companies delivered bids that were $338 million to $518 million higher. Those rival companies claimed CRRC had badly underbid the contract to secure a foothold in the North American market.

Gonneville, the T’s chief operating officer, said the agency is monitoring the contract with CRRC closely. “At this point, there have been no major issues” he said.

John Englander, the legal counsel for the T, said the agency decided to dispense with putting the contract for additional Red Line vehicles out to bid because a bid process would have driven up costs and resulted in procurement delays of 28 months. He said the T could legally negotiate a sole-source contract with CRRC because of the benefits received in terms of price and vehicle standardization. “We know we are getting a good price for these cars,” he said.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...