Answer: A Dirigible Docking Station
In the original plans for the Empire State Building, the massive mast was intended to serve as, of all things, a docking station for dirigible airships. The investors behind the construction of the building insisted that it was a practical investment when, in reality, it was almost entirely a bid to out build the Chrysler Building by 204 feet in order to claim the crown as the tallest building in the world.
Airship captains of the day declared the idea ludicrous and dangerous. The closest anyone came to actually mooring at the mast was a jury-rigged three-minute connection to the top of the building in 40-mile-an-hour winds. Beyond that, there were a few simple flybys for publicity photos. The most popular photo on the subject (and the one seen here) is a composite created to promote the idea of an airship docking with the building. After a few years of attempts and various publicity stunts, the mast was turned over to NBC to serve as a television broadcasting tower.
Image, a composite from 1930, courtesy of the Keith de Lellis Gallery’s 2010 Bird’s Eye View collection.