Submarine History - Age of Sail
The first American submarine is as old as the United States itself. David Bushnell, a Yale graduate, designed and built a submarine torpedo boat in 1776. The one-man vessel submerged by admitting water into the hull and surfaced by pumping it out with a hand pump. The small Turtle held enough air to last one person a half-hour. Powered by a pedal-operated propeller and armed with a keg of powder, the egg-shaped Turtle gave Revolutionary Americans high hopes for a secret weapon - a weapon that could destroy the British war-ships anchored in New York Harbor. The idea was to submerge below a British ship and drive a long screw into the ship's hull. A watertight oak cask filled with gunpowder would then be attached to the screw, and a timed fuse would ignite the explosion.
The history of mine warfare in the United States dates back to the Revolutionary War and David Bushnell, inventor of the first practical submarine. Bushnell created crude mines by packing gunpowder into butter churns and beer kegs and setting them afloat in the Delaware River to drift down onto the British fleet at Philadelphia. As a student at Yale University, Bushnell worked on the development of underwater explosives. In his research, he discovered that gunpowder could be exploded underwater. During the American Revolution Bushnell was authorized to design a sea mine (usually referred to as a "torpedo" by Bushnell) to be used against the British fleet. He filled kegs with gunpowder and assembled a flintlock mechanism adjusted so that a light shock would release the hammer and fire the powder.
Bushnell sent the floating kegs down the Delaware River in December 1777 with the hope that one or all of these kegs would drift into the British ships anchored at Philadelphia. Although this attempt by Bushnell is referred to in history books as the Battle of the Kegs, there was no actual battle. The keg mines [torpedoesl did not meet with success. One of the kegs that had been spotted by two boys exploded when they tried to retrieve it, killing them and alerting the British to be on the lookout for the kegs. The British destroyed the rest of the kegs by firing into them as they floated by.
The Turtle's torpedo, a keg of powder, was to be attached to an enemy ship's hull and detonated by a time fuse. On the night of September 7, 1776, the Turtle, operated by an Army volunteer, Sergeant Ezra Lee, conducted an attack on the British ship HMS Eagle. However, the boring device that was operated from inside the oak-planked Turtle failed to penetrate the target vessel's hull. It is likely that the wooden hull was too hard to penetrate, the boring device hit a bolt or iron brace, or the operator was too exhausted to screw in the weapon. When Sergeant Lee attempted to shift the Turtle to another position beneath the hull, he lost contact with the target vessel and ultimately was forced to abandon the torpedo. Although the torpedo was never attached to the target, the clockwork timer detonated it about an hour after it was released. The result was a spectacular explosion that ultimately forced the British to increase their vigilance and to move their ship's anchorage further out in the harbor. Royal Navy logs and reports from this period make no mention of this incident, and it is possible that the Turtle's attack may be more submarine legend than historical event.
Two more dives were unsuccessful. All was not a total loss for Bushnell and his creation, however, which became known as the first submarine used during a war.
Robert Fulton continued the development of floating mines. In 1797, he proposed to the British that they use drifting mines to attack the French fleet. These mines were supplied with a clockwork mechanism which could be started when the mine was released and would explode 5 to 10 minutes later. This attempt failed when the French fired on the small boats carrying the mines and they had to be released early.
In his next experiment Fulton attempted to destroy a French frigate by building a weapon that consisted of a cable with a mine connected to each end. Fulton released the mine and cable such that the cable would snag the shipTs bow drawing the mines into contact with the shipTs sides as it sailed by. This attempt had also meet with failure when the mines exploded without sinking the ship. He concluded that the experiment failed because the mines were not submerged. In 1805, while working in England, Fulton succeeded in sinking the Dorothea, a 200-ton brig. Fulton made each mine heavier so that it would sink beneath the surface and the connecting cable would draw the mine underneath the ship where it was most vulnerable. This successful experiment led to the conclusion that a weighted mine beneath the surface was more effective than a floating surface mine in destroying a shipTs hull.
Then came another American, Robert Fulton, who successfully built and operated a submarine (in France) in 1801, before turning his talents to the steamboat. Fulton's cigar-shaped Nautilus was driven by a hand-cranked propeller when submerged, and had a kite-like sail for surface power. Nautilus was the first submersible to have separate propulsion systems for surfaced and submerged operations. It also carried flasks of compressed air that permitted the two-man crew to remain submerged for five hours. Napoleon commissioned the first practical submarine, designed by the American inventor Robert Fulton. Testing of this craft, the Nautilus, was successfully carried out in France in 1800-1801, when Fulton and three mechanics descended to a depth of 25 feet. Further tests in Britain, proved successful in destroying heavy brigs in 1805.
Between 1814 and 1861, work to improve upon Fulton's fundamentally sound design continued through the efforts of the American shoemaker Lodner Phillips, the French engineer Brutus de Villeroi, and others. The concepts of air supply storage and replenishment, ballast arrangement and regulation, configuration of movable surfaces for steering and depth control, and instrumentation for navigation and depth determination had all seen varying levels of advancement in these intervening years.
Perhaps the greatest problem was the recurring inability to devise a self-powered propulsion system capable of operation while running submerged. Bushnell had designed into his vessel the new innovation of hand powered oars based upon the principle of the screw. Significantly, this appears to have been the earliest use of screw propulsion in watercraft. Better means of propulsion than hand power were subsequently sought, and although several dual propulsion systems were experimented with (including Fulton's auxiliary sail concept, and McClintock's electromagnetic drive unit), hand power remained the primary means of propulsion for the American vessels built before and during the war.
During this time work also progressed considerably in regard to weapons systems. Far-reaching advancements on developing galvanically controlled underwater explosive weapons were made by Samuel Colt in the 1840s, building upon the work of Bushnell, Fulton, Elijah Mix, Moses Shaw, Robert Hare, and their European contemporaries. Among other things, Colt made progress in the development of contact detonators, remote electrical fire control systems, and multicell voltage storage batteries.
In terms of tactical delivery of the explosive weapon, three general methods were recognized as viable delivery systems: the use of a time-delay explosive charge (basically a limpet mine) carried on the outside of the boat and manually attached to the hull of the enemy vessel, such as was employed by Bushnell's Turtle; the towing of a contact torpedo in the wake of the torpedo craft in which the idea was to detonate the charge by diving beneath the target in such a way that the charge would collide with the target; and variations upon the bow-mounted spar torpedo concept originated by Fulton. McClintock's series of boats would utilize all three of these methods at various stages of their progression.
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