Saturday, September 24, 2005

A Short History of Submersibles

The impulse to travel underwater has fascinated the human race for thousands of years. From early trips like the mythical journey of Alexander the Great to the modern nuclear boats like the powerful Seawolf class in the U.S. Navy, the development of underwater travel, first for scientific reasons, and then for military reasons, has fascinated historians and scientists for centuries.
An example of early interest in underwater exploration can be found in the work of Leonardo da Vinci. He may have produced a proto-type for a submersible wooden-framed boat covered in goatskins, "with oars providing propulsion through waterproof sweeps" (Clancy 1). No surviving information exists about the submersible, so it is unknown whether or not da Vinci tested his invention on the shores of Italy.
In Britain, carpenter and gunner William Bourne designed the world's first true submersible boat. A u-shaped boat with its hull completely enclosed, Bourne's design took into account the need for ballast tanks (weights intended to steady the vessel during travel) — demonstrating his innate understanding of how ships actually float. Bourne's submarine was designed to engineer the ballasts, and thus control the vehicle's submergence and reemergence, by using screws that increased or decreased the amount of water within the tanks. The entire contraption was waterproofed by leather hides, and oars would be used for underwater propulsion, like da Vinci's fabled submersible.
Bourne's design appeared in 1578, but it was not until Cornelius Drebbel, a Dutch physicist and inventor, decided to build a modified version of the boat, did it actually get made. Drebbel's boat became the world's first working submarine when it was launched on the Thames somewhere around 1620. Contemporaries described the boat as 'an enclosed rowboat' manned by twelve men working the oars.1 Despite massive leakage from the greased leather outer protection, the boat managed to stay submerged for long enough to descend to depths of 12-15 feet. The passengers on board became the first people to travel in a working submarine, and the oarsmen the world's first submarine crew.However, the "true significance [of Drebbel's submarine] was the development of an air supply, akin to the modern snorkel, first seen operationally on the German submarine U-539 in January 1944" (Hutchinson 8). Drebbel's submarine projects soon came secondary to his knowledge of explosives, and they were soon abandoned for the more pressing pursuit of developing effective weapons for war.
Throughout the rest of the 17th century, submarines were designed by a variety of early inventors, including Marin Mersenne and George Fournier, both of whom were Jesuit priests; Abbé Giovanni Alfonso Borelli, whose boat contained goatskin ballasts; and lastly, De Son, whose Rotterdam Boat (1653) had clockwork designed to work an internal paddle. However, it was not until 1775 that submarine technology took a giant leap forward when Yale-educated David Bushnell designed and built the Turtle, which became the first boat to be used for military purposes. Manned by Sergeant Ezra Lee, the Turtle, manipulated by hand-cranked propellers (both vertical and horizontal), set off on September 6, 1776 with orders to attack a British warship (HMS Eagle). Constructed with a drill to enable Lee to bore into the ship's hull, the Turtle was to be dragged close to its target where its captain would submerge, attach the explosives and then peddle away. Unfortunately, the Turtle was spotted, and this coupled with the fact that Lee was unable to drill into the Eagle's Hull, ensured the mission was less than successful. Lee released the explosive, and after it failed to hit its target, he beat a hasty retreat.
Military submarines as we know them today have their origins in both the Turtle, and also the Nautilus, a modified Turtle designed and built by Robert Fulton. Fulton, who was American by birth, was living in Paris at the time when the Nautilus was first demonstrated in the Seine. Despite working quite well (Nautilus stayed submerged for six hours at depths of 25-feet), the Nautilus failed to attach its charge to any British ship — and Fulton, abandoned by the French government, never built another version after selling his boat for scrap metal in 1800. In 1804, Fulton ended up on British shores demonstrating his machine to a Navy 'unimpressed' by its 'underhanded' nature (Clancy 3).
After the disastrous attempts by both the Turtle and the Nautilus to actually hit their targets, the Civil War was now the theatre for the evolution of submarine warfare when the H.L. Hunley became the first boat to destroy an enemy's ship. The boat's original captain, and one of its designers, Horace L. Hunley, died during a test run of the boat in 1863. Undeterred, the determined Confederates raised the hull of the boat, renamed the vessel after its brave captain, and sent it off to destroy the USS Housatonic on October 17, 1864. The H.L. Hunley achieved its mission — but it was uA new era of boats had arrived. Now a proven weapon of warfare, the H.L. Hunley paved the way for John Holland's boats — the first "practical combat submarines" (Clancy 3). Irish-American Holland first conceived of the submarines to aid in the Fenian cause, whose Irish Fenian Brotherhood funded his first three boats. In short, Holland's "simple 53-feet nine inches long boat was the forerunner of other submarines purchased soon after by the British, Japanese and Dutch navies" (Hutchinson 23). Holland's designs, including the six boats he contracted to the U.S. Navy in August 1900, definitively moved submarine technology into a whole new era. Now armed with torpedoes that could be reloaded, propelled by an electric motor powered by batteries for submergence and a re-engineered hull for better movement underwater, Holland-designed submarines were in use until the mid-1920s.
Of course, as the boats become essential parts of the quickly evolving Navies of two world wars, technology vastly improved. From the implication of the use of diesel engines to the inspiring use of U-boats by the Germans, submarines emerged as integral aspects of war strategy. The nuclear revolution changed submarine propulsion forever. Now, boats travel faster, move quieter and are armed with weapons so powerful that it is difficult to imagine the extent of their destructive ability . Today, the evolution of the submarine has far surpassed even the imaginations of those early inventors who were utterly dedicated to conquering methods of underwater travel and warfare.nable to remove itself from the wake of its 90-pound explosive charge and was destroyed.


Post a Comment

<< Home