The modification of the Harold Interlocking in Queens – the busiest passenger rail interlocking in North America – was a key component of the Metropolitan Transportation Authority’s (MTA) larger Grand Central Madison program. Located within a 1.5-mile mile corridor marks the converge of three major rail operations, Long Island Rail Road (LIRR), Amtrak and NJ TRANSIT, totaling about 700 trains per day.
STV, in joint venture, as part of its contract with MTA Construction & Development for Grand Central Madison, prepared final design documents for several infrastructure improvements within the interlocking. The team’s recommendations included the addition of two bypass tracks for Amtrak that isolated Amtrak trains from LIRR operations east of the tunnel portals into Manhattan while eliminating at-grade conflicts. Additionally, the design implemented the reinstallation of a track connection to an existing tunnel line with a 30-mph alignment, new connections to an existing loop track, alignment for an additional loop track and a relocated primary route alignment for LIRR.
By itself, the modification of Harold Interlocking was substantial enough to be the MTA’s largest infrastructure project. In concert with Grand Central Madison, it emblemized the enormous technical complexity of the project.
