Courtesy Mary Habstritt.
This 1930's shot was taken looking West along 30th Street from around 11th Avenue, as the High Line was being built. Construction equipment can be seen mounted onto temporary rails. Cranes were built to pass over the trains in the rail yards.
The photo was part of a construction survey done by contractors the George A. Fuller Company. The Fuller Company (which still exists) was formerly one of the largest construction companies in the world. The Company worked on the Lincoln Memorial, the National Cathedral, and the Louisiana State Capitol, among many others.
As the catalogue label shows, the High Line was referred to as the NYC Viaduct, and the architect is listed as NY Central, the rail road. Again, the Miller Elevated Highway can be seen in the background.
A historical birds-eye view is here