Overview of Rebuilding. The more than 130 year-old Park Avenue Viaduct around the MTA Metro-North Railroad Harlem-125 Street Station in New York, New York, is undergoing a multi-year rebuild to enhance its long-term sustainability. On Sunday, April 6, 2025, the station was bustling with activity as Train 6323 had just departed for Grand Central Terminal while Train 9627 was heading to Southeast, New York. On Track Three, MNCW GP35r work locomotives 103 and 102 are moving a train of continuously welded rail that will drop “sticks” of rail on all four tracks during the day, both for planned work projects and to be held in reserve for emergency use. The Mi-Jack gantry crane in the background has been replacing the structure with pre-fabricated sections for more than a year, and the entire project is planned for completion in 2027.