From the article:

After planned signal upgrades meant a 10-week shutdown of the line in 2024 — and continued work on the signaling system meant scattered outages weeknight and weekend outages last year as well — riders in Greenpoint were angered to learn this spring that there would be yet more weekends with no G train service this summer.

MTA officials said they’d discovered a leak in the tunnel under the Newtown Creek — and that repairing it alongside the ongoing upgrades meant taking the trains out of service for multiple weekends between the Bedford-Nostrand and Court Sq. stations.

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“We are making a massive investment in the modernization of this line,” Torres-Springer said. “It will only be the fourth line across the 22 lines that will be fully re-signaled.”

“We’ve enabled cell service across the entire G line as part of this work,” he added. “Five more stations [will] become A.D.A. accessible.”

Torres-Springer also noted the MTA’s decision last year to swap out all the line’s older subway cars for the state-of-the-art R211.

But the primary reason for the work — the cause of the shutdowns that began in 2024 — is the first one: the installation of modern computerized signaling, known as communication-based train control, or CBTC.

The system — which is already in place on the L train, the No. 7 train, portions of the E, F, M and R trains — will allow the MTA to precisely track trains in the tunnels, letting them safely run more closely together. The upgrade will also streamline dispatching, allowing trains to be routed from the MTA’s Midtown rail control center.

To install the new system means putting in brand new switches and new traffic lights. It means adding small wireless transponders at regular intervals along the tracks, along with 5G radios to let them communicate. And it means wiring all of those devices up to a computer that can control them while talking to dispatchers.

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MTA officials expect to conduct more than a year of testing, troubleshooting, and software tweaks before turning the new system on. A large keyed switch in the newly-minted Train Control Room up the tracks at Court Square was marked “LEG[ACY]” for the existing signal system and “CBTC” for the new one. Workers can flip it back and forth for upcoming tests.

But MTA officials say it will be late 2027 or early 2028 before that switch is flipped for good. And all along the track-side, new signal lights were covered in black plastic, so as not to confuse train operators before the new system comes online.

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Torres-Springer said the damage could be traced back to repairs done in 2015 after 2012’s Hurricane Sandy.

That’s when “the old MTA,” as he put it, “made some repairs, but left the leaks to be remediated by somebody in the future.”

“We’re not doing that,” he said. “We went in and we saw that the leaks were extensive, and we’re repairing them.”

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MTA spokeswoman Sophie Deixel told The News that work crews had managed to drill along 1,000 feet of the tunnel that weekend — 100 sets of holes — and pump grout along 450 feet of tunnel.

Each tube of the 95-year-old tunnel is 3,200 feet long. The MTA estimates it will take until the year’s end to seal them both.