The North River Tunnels carried PRR trains under the Hudson; for some years PRR electric engines also pulled Lehigh Valley Railroad or Baltimore and Ohio Railroad trains to New York. The East River Tunnels carried LIRR and PRR trains to the Sunnyside Yard in Queens. As part of the New York Connecting Railroad improvement project, a connection from the East River Tunnels to the New Haven Railroad tracks was also built. New Haven trains began running through the East River Tunnels, serving Penn Station, in 1917 after the Hell Gate Bridge opened.
