Up to the late 1960's, Union Street, between the Jordan Creek and Lehigh River, was crossed by numerous train tracks. In addition to the main tracks for the New Jersey Central and Lehigh Valley Railroads, the area hosted many sidings for the industries that once huddled along this historic river front area. There was a small rail yard with five sidings between the UGI gas storage tank, which dominated Allentown's skyline, and Allentown Meat Packing Company. The photo above dates from the late 1940's. The map below from the early 1930's.
Small rail yard on bottom left of map. Allentown Meat Packing was the former H.H. Steinmetz Co. in 1932.