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ASK OCE — September 20, 2006 — Vol. 1, Issue 14


At midnight, September 7, 1776, a revolutionary naval craft made its way slowly and silently down the Hudson River towards the mighty British fleet that was anchored in New York Harbor. The seven-foot tall, six-foot wide, egg-shaped submersible ship — dubbed the Turtle — was the world’s first functional submarine.

The Turtle’s inventor was a former farmer and Yale graduate, David Bushnell of Connecticut. Made of oak reinforced with iron bands, the craft was equipped with a windowed copper conning tower, two hand-cranked propellers, and a 100-pound time bomb on its back. A single pilot entered the ship through the now familiar type of airtight hatch at the top, sat on a stool inside the vessel, and maneuvered the ship with hand-cranked propellers — a large one at the front and a smaller one at the top — and a rudder at the back.

The surprisingly versatile Turtle could float on the water’s surface and pump in fresh air through a one way, leak-proof intake valve before submerging. However, the pilot could only stay underwater as long as his air lasted before resurfacing. 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 filled with gunpowder that was fastened to Turtle’s hull.

Although Bushnell had some assistance with the various apparatus of his craft, the overall design was entirely his own. Another notable inventor, Benjamin Franklin, was among the admirers of Bushnell’s first successful trial runs at Saybrook River, Connecticut, in the summer of 1775.

Bushnell’s September 7, 1776, attack plan called for piloting the Turtle under the 64-gun flagship of the British fleet the HMS Eagle, boring a hole into the wooden keel of the enemy ship, lighting the timer fuse, and then detaching both the screw and the mine. The mine would then explode and sink the British vessel.

Bushnell himself was too frail to pilot the craft, and its usual captain, Bushnell’s brother Ezra, was ill at the time of the mission. A volunteer, Sergeant Ezra Lee, had to be hastily trained. Lee reportedly moved the craft into position undetected under the HMS Eagle with perfect precision but at this point, Turtle’s luck ran out; apparently Lee could not drill the screw through the copper-plated hull of the British ship. After a failed second attempt, the mission had to be abandoned.

In two later battles at Fort Lee on the Hudson, Turtle again proved adept at moving into position but nonetheless failed in its efforts to attach mines to the undersides of the targeted British ships. These failures aside, General 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.”


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