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DAVID BUSHNELL (1740-1826)
The most sensational contribution of patriot and inventor David Bushnell to the American Revolutionary War effort was the world's first functioning submarine.
David Bushnell was born in 1740 in West Saybrook, Connecticut, where the Connecticut River meets Long Island Sound. He worked on his family's farm until the age of 31, when he entered nearby Yale College.
By the end of that summer, Bushnell had solved his problem by inventing a vessel he called the "Turtle": the first submarine. The Turtle did not resemble that animal, but rather a huge walnut, seven 1/2 feet tall and six feet wide at the center, made of oak reinforced by iron bands. A single operator entered through the now familiar type of airtight hatch at the top, sat on a stool inside the vessel, and maneuvered the machine with hand-cranked propellers --- a large one at the front and a smaller one at the top --- and a rudder at the back. The Turtle could float on the water's surface and pump in fresh air through a special, leak-proof intake valve before submerging; the operator could only keep the vessel under water until that fresh air became stale. Although Bushnell had some help with the various apparatus of his craft, the overall design and many of the details were entirely of his own creation.
The Turtle also had an oversized wood screw sticking straight up from its top, with its handle inside the vessel's chamber. Attached to this screw was a waterproof fuse that led to the mine, which was buoyant but fastened to the outer hull. Bushnell's plan of attack was for the operator to steer in secret under an enemy ship, drill the screw deep enough into the keel of the enemy ship to anchor it, then detach both the screw and the mine, set the fuse burning, and drive away as quickly as possible. The mine, held by the drill-bit and its own buoyancy against the bottom of the enemy ship, would explode and sink the ship. Among the admirers of Bushnell's first successful trial runs at Saybrook in the summer of 1775 was another inventor, Benjamin Franklin.
The Turtle finally saw action in 1776. The British navy was blockading New York City, intending ultimately to invade along the Hudson River. Bushnell had his invention ferried down from Connecticut by ship. He targeted the British flagship, the HMS Eagle, as the Turtle's first victim. However, Bushnell himself was too frail to pilot the craft, and his usual captain, his brother Ezra, was ill with a fever. A volunteer was quickly trained to operate the machine, and the mission began.
The Turtle moved with perfect accuracy and stealth; but the operator could not drill the screw through the copper-plated hull of the British ship, and had to abandon the mission. At most the Turtle's efforts may have spooked those on board the ship, who could tell that something was attacking the bottom of the ship but could not see what it was. In two subsequent battles at Fort Lee on the Hudson River, the Turtle again swam splendidly but failed to bite. Nevertheless, George Washington appointed Bushnell to a commission in the Corps of Engineers, hailing him as "a man of great mechanical powers, fertile in invention and a master of execution."
After 1776, Bushnell abandoned the Turtle and returned to inventing variations on the standard naval mine, including a "drift" model that exploded on contact. Bushnell's mines helped hamper and harass, as well as destroy, British ships throughout the War.
In 1787, Bushnell disappeared from his home in Saybrook. Only after his death, in 1826, did it become known that he had moved to Georgia and become a doctor and professor, under the name of David Bush. It is not clear whether Bushnell had fled his former career, or disappointment with the Turtle, or something else entirely. But he hopefully did take pride in the fact that he built the world's first functioning submarine and helped establish the American spirit of innovation.
A 1976 replica of the Turtle is on permanent display at the Connecticut River Foundation in Essex, Connecticut. Contact the Foundation at P.O. Box 261, Essex, CT 06426.