The Chinese manufacturer that won the bid to produce new rail cars for SEPTA has begun testing cars ordered by Boston.

Last spring, the company, CRRC MA, was awarded a $137.5 million contract to make 45 new cars for SEPTA's Regional Rail. The cars being tested for the Massachusetts Bay Transportation Authority are subway cars, not the same as the heavy railroad cars SEPTA has ordered, but they are the first American rail cars CRRC MA has built, and Philadelphia's transportation authority is paying attention to how they perform.

SEPTA is staying in close contact with MBTA officials during the testing process, said Andrew Busch, a SEPTA spokesman. Cooperation between the two cities will increase in the coming year when CRRC MA opens its first American manufacturing facility.

"SEPTA will have personnel in Boston for the plant opening, and then we will continue with close monitoring of the progress on our multi-level rail car order," Busch said.

Busch noted the SEPTA vehicles are essentially carriages that will be pulled by locomotives. They have no independent propulsion systems, making them much less complex than the Regional Rail's Silverliner IV and V cars, which each have their own engines.

CRRC MA is an interesting new player in the American rail car scene. Its parent company, China Railway Rolling Stock Corp., is the biggest rail car manufacturer in the world and is making a big investment in American manufacturing with the construction of a facility in Springfield, Mass., expected to open in 2018.

The company has drawn flack for massively underbidding competitors. That has drawn attention from Congress, which has inquired about the low bids being possible due to subsidies from the Chinese government. The company's winning bid in Philadelphia was $47.2 million less than the bid from Hyundai Rotem, a South Korean firm with a manufacturing facility in Philadelphia.

Perhaps of greater concern to Philadelphia area riders ahead of CRRC's promised 2019 delivery of the SEPTA cars is the company's lack of experience with American rail car construction. CRRC MA received an adequate technical rating in SEPTA's review of three bids for the contract.

SEPTA officials have said they're looking at Boston as the canary in the train tunnel, so to speak. They're hoping that any of the kinks that come out of an untried company converting to American manufacturing standards will be worked out with the Boston contract, not their own.

Boston's MBTA has $842 million in contracts with CRRC MA for 404 cars. Those being tested this week are pilot subway cars that were built in Changchun, China, an MBTA spokeswoman said Thursday. Currently,  routine testing is being conducted in China and, upon their December arrival in Boston, qualification and commissioning testing will begin on that city's rails, the MBTA reported. CRRC MA  is expected to shift production to its Springfield plant in spring 2018.