David Bushnell's Turtle: The Revolutionary War's First Combat Submarine

During the American Revolution, Connecticut inventor David Bushnell designed the Turtle, the world's first combat-ready submarine, as a secret weapon for the patriots against the British Royal Navy. The acorn-shaped, oak-and-iron vessel was intended to attach a bomb to an enemy warship's hull. On the night of September 6-7, 1776, pilot Ezra Lee attempted to attach the charge to the HMS Eagle, the Royal Navy flagship, but failed because the screw could not penetrate the metal hull. Two subsequent attempts by Lee and Phineas Pratt also failed. The Turtle's fate is unknown; the British sank the sloop transporting it in October 1776, though Bushnell claimed to have salvaged it. Historians note that the Turtle's attacks failed and it did not herald the age of the submarine, but it represented an early asymmetric weapon. Bushnell's innovations included a pedal-operated propeller and a hand crank, which were precursors to screw propellers. The Turtle also used foxfire, a bioluminescent fungus, to light its compass and barometer. Historian Mark Jacobson connects the Turtle to later developments like WWII frogmen and Navy SEALs. George Washington praised Bushnell as 'a man of great mechanical powers' and 'an effort of genius.' The story is featured in Smithsonian magazine's special report on America's 250th Anniversary.