Ben Franklin (PX 15) explores Gulf Stream

On July 12, 1969 – two days before the launch of Apollo 11 to the moon – the pioneering submersible, Ben Franklin, with its six-man crew undertook a 30-day mission of drifting 1500 miles from Florida to Maine to sample, measure, and explore various aspects of the huge underwater Atlantic Ocean current known as the Gulf Stream at depths between 500 and 1800 feet.  The 50-foot, 130-ton battery-powered craft or “mesoscaphe” was the brainchild of Swiss engineer and explorer Jacques Picard (see Trieste and the Challenger Deep) and built between 1966 and 1968 by Grumman Aerospace Corporation with funding and instrument contributions from the United States Navy.

Helm of the Benjamin Franklin, 1969

The mission was a multi-faceted success, increasing the general knowledge of currents; measuring the gravitational, magnetic and topographical properties of the ocean floor along the Continental Shelf, as well as observing the biology of the Stream (e.g. fish and fish noises) which was surveyed for the first time in a continuous and uninterrupted way.  Not only a magnificent example of oceanographic research, due to the quiet drift of the vessel, the American military also used the mission to study and simulate the possibilities of an enemy craft creeping undetected up the entire eastern seaboard of the United States.  And through the offices of Dr. Wernher von Braun, the NASA scientist Chet May became a member of the Ben Franklin crew to learn the effects of prolonged isolation on people since an undersea environment was close in character to space travel, including the soon-to-be launched Skylab mission.

Before its retirement in 1971, the so-called PX-15 was used as a training vessel by Robert Ballard, best known as the discoverer of the Titanic in 1985.   The Ben Franklin was named for the American statesman and scientist who first charted the Gulf Stream and published a map of it in 1769 — exactly 200 years before the 1960s mission.

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