Grand Central opening of LIRR service still delayed as engineers struggle with vent fan problem

When Long Island Rail Road commuters start riding to and from Grand Central Terminal will depend on how a ventilation fan blows.

MTA Chairman and CEO Janno Lieber wouldn’t commit Wednesday to starting service this month.

“January is possible,” Lieber said. “But I’m not putting a date on it.”

MTA bosses had planned to start the service before the end of 2022 — but vent fan problems disclosed in December have gummed up the agency’s plans.

The fan is supposed to suck air from the new LIRR platforms, which are in a giant cavern 175 feet below street level.

“There’s one area that is near the entrance from the existing Grand Central lower level where the exhaust system was not able to suck enough air,” Lieber explained.

The problem, he said, is that “there were counteractive airflows that were coming from existing Grand Central.”

Those counteractive airflows, which Lieber also described as a “downdraft,” interfere with the fan’s ability to move enough air — measured in cubic feet per minute — from the new terminal.

“It’s a little technical, but that is literally it,” Lieber said. “We are addressing those engineering issues with a variety of tools.”

The Grand Central Madison project — which has a $12.7 billion price tag, and has been 25 years in the planning and construction — is “done done,” said Lieber.

The last hurdle is that pesky fan.

“It’s a code issue, a safety issue,” Lieber said. “It is as if you had walk-through of a house that is done, and you could smell the new house, and you could smell the new paint, and they told you there is still a village code inspection that needs to take place.”

The project to bring the LIRR to Grand Central — known in its early days as East Side Access — has been plagued by cost overruns and delays since planning began during the administration of Gov. George Pataki in 1997.

“For years when there were problems with East Side Access, the answer was we are going to push it back three years, four years, an untold number of years,” Lieber said.

“We are getting it done. The thing is finished,” he said. “Now we are counting days and weeks and struggling through this one last issue.”