Bushnell's Submersible Torpedo Boat

 

First War 

Bushnell's Submersible Torpedo Boat, 1776. Cutaway by Lt. Col. F.M. Barber, 1885, based on Bushnell's description. (detail)

Submarines were first used as offensive weapons in naval warfare during the American War of Independence (1775-1783). Invented by Yale student David Bushnell, the one-man boat "Turtle" was made of an upright walnut-shaped piece of wood (see photo). Underwater, the boat was powered by a driver turning a propeller. The plan was for the Turtle to approach a British warship underwater, load the hull with gunpowder using a screw device operated from inside the ship, and then leave the ship before a timer would detonate the charge. In a real attack, however, Turtle was unable to drive the screws through the copper cladding of the hull.

  A precursor to the conning tower, with glass-covered portholes, allowed observation from inside the ship. The Nautilus dived by taking up water in ballast tanks, and a horizontal "rudder", a precursor to a submarine, helped to keep the boat at the desired depth. The submarine contained enough air to survive for four men and to keep two candles burning underwater for three hours. Tanks of compressed air were later added.

 

The Nautilus, like the Turtle, was intended to plant explosives in the hulls of enemy ships. Fulton experimentally sank an old schooner anchored at Brest, but was unable to outrun any ships he saw as he tried to destroy British warships. French interest in Fulton's submarine waned, and he traveled to England to offer his invention to his former enemy. In 1805, the Nautilus sank the brig Dorothy during trials, but the Royal Navy did not support his efforts. Fulton then came to the United States, where he was able to gain Congressional support for a more sophisticated underwater vehicle. This new submarine was intended to carry 100 people and was powered by a steam engine. However, Fulton died before the ship was actually completed, and the submarine, named Mute, decayed and eventually sank at anchor.