The operators of the MBTA’s commuter rail are taking aim at fare-skippers and have proposed a solution: a “ring of steel.”

That’s the name Keolis gave to a set of fare gates the French company is considering installing at North, South and Back Bay stations — those most flocked with commuters at rush hour — as a way to fight back against fare evasion.

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Keolis Deputy General Manager Franck DuBordieu told the State House News Service it would invest $10 million to install the equipment if the T changes “the current way things are managed around revenue.”

The gates could generate $24 million each year in fares riders would otherwise avoid paying, according to Keolis.

A study the company conducted in March found 15-20 percent of passengers — who show their passes to ticket-takers on the train — didn’t pay the proper fares. Keolis’ Peter Williams, who is leading the fare evasion initiative for Keolis, estimated the company loses $35 million a year to fare-skippers. 

The full report is available on the T’s website.

Fare evasion remains a problem on the Green Line and on buses, too, according to estimates the MBTA released Monday.

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Between $1.3 and $4.5 million is lost on the Green Line and between $1 million and $2.4 million is lost on buses to people who sneak aboard without paying fares, the T said.

As the T works to capture as much of that fare money as possible, Brian Kane, the T’s director of operations, said it’s probably impossible to collect fares 100 percent of the time on trolleys.

That’s “very rarely achieved outside of totalitarian dictatorships,” he said.

The State House News Service contributed to this report.