In 1907 the New York State Public Service Commission was chartered to oversee subway expansion in New York City (the Dual Contracts). Although the Lexington Ave Line was opened in 1904, sometime before 1924 this cover was installed at East 112th St. and Lexington Ave.
The dual strand basketweave design here has 12 blocks all of which have been drilled for ventilation. Note that there is no line between PSC and IRT
The dual strand basketweave design is perhaps the most common design in New York.
Bronx, Manhattan, Brooklyn, Queens along the IRT lines.