The trains will resume operations through Hoboken on March 24 following the repair of a substation flooded by the Oct. 29 storm.
"We think it's a significant step forward and, frankly, we're delighted we can take it," NJ Transit Executive Director James Weinstein said.
Electric trains make up a significant portion of the fleet that normally rolls through Hoboken. Weekday service has been running on a reduced schedule while pre-storm weekend service was restored in December.
The agency will add 21 additional weekday trains out of Hoboken and restore full service to 19 trains running abbreviated trips.
The storm decimated the Hoboken station and flooded a substation that provides electrical power that allows trains to run through it. Diesel trains have been used instead.
The lack of electrical power also prohibited NJ Transit from diverting trains to Hoboken if there were problems on the Northeast Corridor line.
"It's taken us this amount of time just to do the interim fix to it," Weinstein said of the substation. "Hopefully we'll be able to replace that facility in the near future," with funds from the Federal Transit Administration, he said.
NJ Transit suffered at least $400 million in damage to its locomotives, rail cars and infrastructure during Sandy.
About 20 percent of the fleet was damaged when rail yards that were supposed to shelter trains from the storm flooded. The storm also destroyed equipment and replacement parts that have been hard to come by, slowing repairs.
"It's all pretty sophisticated equipment and it's not the kind of thing you can go to Home Depot and order off the shelf," Weinstein said. "It's all specially manufactured for this equipment."
NJ Transit said that 272 rail cars were damaged in the storm; 97 have been repaired. Seventy locomotives sustained damage and 45 have been fixed.
Weinstein said he is pleased with how the agency has rebounded after Sandy but repairs, especially to infrastructure, will take time due to the severity of the storm.
"In the interim, despite the fact that we have damaged equipment and damaged infrastructure, we have managed to serve the majority of the needs of our passengers," Weinstein said.