Work crews will shut down one of Amtrak's two tunnels under New York's East River during the weekends as part of a four-year project to replace track and repair drainage problems.
Amtrak and the Long Island Rail Road said Wednesday the repairs should not affect their train service. The LIRR shares Amtrak's tunnels.
"It's something we wanted to do for a while now," said Amtrak spokesman Cliff Cole. "The whole area's been in need of an upgrade."
Crews will work in one of the tunnels from 10 p.m. on Friday to 5 a.m. Monday, Amtrak said. Beginning next year, they will work in both tunnels.
Each tunnel has four tracks. Amtrak plans to put in new rails and ties, rock ballast and a new drainage system. The work will last through the middle of 2015.
In May a broken rail in one of the tunnels caused an Amtrak train to derail, resulting in a week of delays for commuters.
An inspection after the derailment revealed serious water drainage problems, the LIRR said in a written statement.
Both railroads plan to run their regular schedule of trains during the repairs.
Amtrak has said it needs to modernize and expand its tunnels through the New York area. Planners had hoped to build a new $8.7 billion tunnel under the Hudson River that would end at a new station deep under Manhattan's 34th Street. That project fell through last year after New Jersey Gov. Chris Christie balked at his state's share of the cost.
Amtrak is now studying whether to build a less ambitious Hudson River tunnel, known as the Gateway Tunnel. That tunnel would join up with existing tracks at Penn Station.