Who Invented the Submarine?

It is the ultimate naval weapon, lurking unseen beneath the waves. It can travel the world's oceans at will and appear without warning, unleashing a deadly salvo of ship-killing torpedoes or even world-ending nuclear missiles before melting away back into the depths. It is, of course, the submarine. But the stealthy, ultra-sophisticated nuclear submarines of today do not suddenly appear fully formed. They are the product of more than a hundred years of slow, painstaking, and often dangerous technical development, full of countless failed experiments, dead ends, and lost lives. Not for nothing is submarining called the silent service. And while the submarine as a viable weapon is only a little over a century old, serious attempts at waging underwater warfare go back much further. All the way back, in fact, to the American Revolutionary War, when a primitive hand-cranked wooden submersible made history's first attempt to attack a single warship from below. This is the story of the Turtle, the world's first combat submarine. The ability to strike silently and invisibly from below the waves has enticed naval planners for centuries. In the late 15th century, OG Renaissance man Leonardo da Vinci sketched out plans for designs for military diving suits and submersibles, and even claimed to have devised a method for remaining underwater for extended periods. However, he never described these methods in detail, writing in his notebook, I do not describe my method of remaining underwater and how long I can remain without eating, and I do not publish nor divulge these by reason of the evil nature of men who would use them for assassinations at the bottom of the sea by destroying ships and sinking them together with the men in them. Sure thing, Leonardo. It would be another hundred years before the world's first navigable submarine was built by Dutch engineer Cornelius Jacobzoon Drebbel, court inventor to King James I of England. Constructed in the manner of two wooden rowboats joined together and covered in leather to make it watertight, Drebbel's craft was propelled by oars fitted through flexible leather gaskets and featured a rudder for steering and pigskin bladders connected to the exterior of the hull which acted as ballast tanks. Originally, the necks of the bladders were tied off using string. To dive the vessel, the strings were untied, allowing water to rush in. To surface, the crew squeezed the bladders, forcing the water out and increasing the vessel's buoyancy. Even more impressive, Drebbel's design reportedly included a system for maintaining a breathable atmosphere. Though the details were not recorded, it is likely that Drebbel heated potassium nitrate or saltpetre to generate oxygen and laid out trays of sodium hydroxide or lye to absorb carbon dioxide. Between 1620 and 1624, Drebbel constructed three submarines of increasing size, with the third and final model being propelled by six oars and capable of carrying up to 16 passengers. The craft was tested many times in the River Thames, with contemporary reports claiming that it could travel from Westminster to Greenwich and back in around three hours while submerged to a depth of three to four meters. King James himself is even said to have taken a short ride, making him the first monarch to travel underwater. However, several historians argue that these claims are highly exaggerated and that Drebbel's craft was little more than a semi-submersible capable of only drifting with the current. Whatever the case, despite 15 years of development and demonstrations, Drebbel failed to interest the Royal Navy in his design and the project was ultimately abandoned. Though many inventors over the following decades would try their hand at creating military submarines, it would not be until the late 18th century that technology had advanced sufficiently to make this dream a practical reality. Enter David Bushnell and the Turtle. David Bushnell was born on August 30, 1740 in Westbrook, Connecticut, the son of farmers Namier and Sarah Bushnell. The early part of his career is poorly documented and appears to have been largely uneventful, with Bushnell spending much of his spare time on the family farm reading up on various scientific and technical topics. It was not until 1766, following the death of his parents and two sisters, that he decided to spend his inheritance and pursue a formal education. In 1771, at the age of 31, he was accepted into Yale College. At Yale, Bushnell and colleague Phineas Pratt researched the problem of detonating gunpowder charges underwater, which was previously thought impossible. However, starting with two ounces of gunpowder and gradually working his way up, Bushnell eventually developed a waterproof explosive charge capable of sinking a military vessel, which contained two pounds of gunpowder and was set off by a clockwork timer connected to the flintlock sparking mechanism of a musket. Though known today as naval mines, at the time such devices were referred to as torpedoes after the torpedo fish or electric ray, which delivers a powerful electric shock to stun its prey. Thus, when Rear Admiral David Farragut issued his immortal command, Damn the torpedoes, full speed ahead, at the 1864 Battle of Mobile Bay, he was referring to stationary mines and not more modern motor torpedoes, which would not be perfected for another half-century. After graduating from Yale, Bushnell returned to his brother Ezra's farm near Old Saybrook in Connecticut, where he began building a small one-man submersible to stealthily deploy his ingenious torpedoes against enemy warships. At the time, tensions between the British authorities and the American colonies were steadily rising. They would eventually boil over on April 19, 1775, with the firing of the shot heard around the world at Lexington and Concord, which touched off the American Revolutionary War. Built in cooperation with his brother Ezra, Phineas Pratt, and brassworker and clockmaker Isaac Doolittle, Bushnell's pear-shaped craft measured 2.3 meters long by 1.8 meters deep by 1.8 meters wide, and was built from oak staves bound together with iron hoops like a barrel. As the two halves of the hull resembled turtle shells, the vehicle was dubbed the Turtle. The hull was topped by a small brass conning tower with glass viewports which could be hinged open for ingress and egress, and was propelled through the water by a pair of brass propellers, one on the front for horizontal motion and one on top for vertical motion. Incredibly, this was the first recorded use of screw propellers on a vessel of any kind, predating the widespread adoption of this technology on steamships by nearly a hundred years. These, like all the Turtle's brass fittings, were designed and cast by Isaac Doolittle. Inside the hull, the operator drove the forward propeller using a set of foot pedals and steered the Turtle with a rudder connected to the wooden tiller. The craft was kept upright by lead ballast and submerged and surfaced by pumping water in and out of the ballast tanks under the operator's feet. For navigation, the operator was provided with a depth gauge and a compass, the needles of which were fitted with pieces of bioluminescent foxfire fungus so that they could be read in the dark. The hull held enough air for around 30 minutes of submerged operation, whereupon the operator was forced to surface and replenish the air using a bellows and a set of ventilator pipes attached to the conning tower. The Turtle was armed with a single 150-pound gunpowder charge and a clockwork delay fuse which could be screwed into the hull of a target ship using a hand-cranked auger. Due to the builder's commitment to secrecy, records of the Turtle's development and testing are spotty. It is known that in 1771, Bushnell met with Jonathan Trumbull, the governor of Connecticut, seeking funds to help complete the submarine. Trumbull duly forwarded Bushnell's request to Thomas Jefferson and General George Washington and, on November 9, 1775, one of Bushnell's Yale classmates, Dr. Benjamin Gale, wrote to Silas Dean, a delegate to the Continental Congress, I now write with the greater freedom as I conclude by the time this reaches you the machine will be in camp. Lately he has conducted matters and his designs with the greatest secrecy, both for the personal safety of the navigator and to produce the greatest astonishment to those against whom it is designed. If this projection succeeds, of which I make no doubt, as I well know the man and have seen the machine while in embryo, and every addition made to it fills me with fresh astonishment and surprise. And you may call me a visionary, an enthusiast, or what you please, I do insist upon it, that I believe the inspiration of the Almighty has given him understanding for this very purpose and design. If it succeeds, a stipend for life, and if he fails, a reasonable compensation for time and expense, it is due from the public. What astonishment it will produce, and what advantages may be made by those on the spot, if it succeeds, is more easy for you to conceive than for me to describe. I congratulate you and my country in the begun success of our arms to the northward, and the prospects of further success. Make my most respectful compliments to Dr. Franklin and our delegates, your associates, and am, most respectfully, your sincere and most humble servant." Soon after, Benjamin Franklin visited Bushnell in Old Saybrook and toured the still-incomplete Turtle. While Franklin, Jefferson, and avid inventors in their own right were intrigued by the project, Washington was initially hesitant to commit any more of the Continental Army's already stretched budget. However, he eventually relented and some funds were released. Nonetheless, construction and testing of the Turtle proceeded slowly. The project, being beset by numerous technical difficulties, for example, the operation of the submarine required considerable stamina and coordination on the part of the operator, who not only had to crank the propellers and operate the rudder, but also navigate continuously, adjust the craft's depth, and also perform the complex task of fixing its explosive payload to the target. Indeed, during initial testing at Ayers Point on the Connecticut River, David Bushnell discovered that he was far too frail to pilot the craft, and instead designated the task to his brother Ezra of the Continental Army. Another unexpected difficulty was that in cold weather, the foxfire fungus fixed to the instrument dials lost its luminescence, making the instruments impossible to read. On December 7, 1775, Dr. Benjamin Gale wrote to his colleague Silas Deane, asking, If you could inquire of Dr. Franklin whether he knows of any kind of phosphorus which will give light in the dark and not consume the air. He has tried a candle, but that destroys the air so fast he cannot remain underwater long enough to affect the thing. However, no solution was forthcoming, forcing Bushnell and his colleagues to sideline the turtle over the winter months. These delays elicited considerable skepticism and annoyance throughout the Continental Army, with militia leader Samuel Osgood writing to John Adams in October, 1775, that The famous Waters machine from Connecticut is every day expected in camp. It must unavoidably be a clumsy business, as its weight is about a ton. I wish it might succeed, and the ships be blown up beyond the attraction of the earth, for it is the only way or chance they have of reaching St. Peter's Gate. Indeed, while the turtle was originally intended to counter the blockade of Boston Harbor, by March, 1776, the British fleet had already withdrawn to Halifax in Nova Scotia. However, the Royal Navy still occupied New York Harbor, which soon became the turtle's new target. In the late summer of 1776, General Washington met with David Bushnell to finalize the plan of attack, and the completed turtle was transported from Old Saybrook to Long Island Sound. On August 27, the Battle of Long Island ended with the British taking control of the western half of the island, forcing the turtle to be moved again to New Rochelle on the Hudson River. At the same time, Ezra Bushnell suddenly fell ill, and David asked General Samuel Parsons to find volunteers. Sergeant Ezra Lee of the Continental Army soon stepped forward, and spent two weeks familiarizing himself with the submarine's operation. Finally, in early September, 1776, Turtle was towed to lower Manhattan and made ready for its first mission. At 11pm on September 7, 1776, Sergeant Lee climbed aboard the Turtle and set off down the Hudson River into New York Harbor. His target was HMS Eagle, a 64-gun ship-of-the-line and flagship of Admiral Richard Hoe, moored off Governor's Island. It was hoped that destroying such a valuable and symbolic target would deal a serious blow to British morale. The journey to the anchorage was a grueling one, with Lee having to fight a stiff tidal current and navigate the harbor in near-complete darkness. His 30-minute air supply also forced him to surface frequently along the way. But at last, two hours after casting off, he reached the Eagle undetected and set about deploying his deadly cargo. But once again, Lee ran into serious problems. Still fighting the current, overwhelmed by having to simultaneously operate the propeller's rudder, ballast, pump, and torpedo auger, and likely suffering from carbon dioxide poisoning, Lee struggled to keep the Turtle in position beneath the Eagle. Worse still, when he tried to drill into the Eagle's hull, the auger refused to penetrate. It is often claimed that Lee was defeated by copper plates on the hull designed to counter wood-eating shipworms. However, the Eagle had not yet been fitted with such plates, and in any case, the plates themselves were paper-thin and would have offered no resistance to Lee's auger. More likely, the wood was simply harder than anticipated, or Lee had accidentally struck an iron plate connected to the ship's steering mechanism. Whatever the case, with daylight approaching, an exhausted Lee soon abandoned the attempt and surfaced the Turtle to replenish his air supply. He was soon spotted by British soldiers stationed on Governor's Island, who rode out in a small boat to investigate. Thinking quickly, Lee armed and released his torpedo and started heading back to base. Upon spotting the small floating shape, the soldiers grew suspicious and withdrew, allowing Lee to slip away. The torpedo drifted into the East River, where it eventually detonated, throwing up a huge column of spray. Though unsuccessful, the September, 1776 attack on HMS Eagle marked the first time in recorded history a submersible craft had ever been used in combat. Over the next few months, two more, less well-documented attacks were carried out against British shipping, though these two were unsuccessful. And before the Turtle could be deployed again, the sloop serving as its tender was sunk by British forces on November 20, 1776, during the Battle of Fort Lee. Bushnell claimed to have successfully salvaged the submarine, though due to budget constraints it was never used in combat again. To this day, the ultimate fate of the historic craft remains a mystery. Undaunted, Bushnell continued to develop various schemes involving underwater explosives. On August 13, 1777, he launched an attack against the British frigate HMS Cerberus in Black Point Bay. This was a mission later recorded by physician and writer James Thatcher in his military journal during the American Revolutionary War. It reads, In the year 1777, Mr. Bushnell made an attempt from a whale boat against the Cerberus frigate lying at anchor by drawing the machine against her side by means of a line. The machine was loaded with powder to be exploded by gunlock, which was to be unpinioned by an apparatus to be turned by being brought alongside the frigate. This machine fell in with a schooner at anchor astern of the frigate and concealed from his sight. By some means it became fixed and exploding, demolished the schooner. Commodore Simmons discovered about eleven o'clock in the evening a line towing astern from the bows. He believed that some person had veered away by it and immediately began to haul it in. A sailor belonging to the schooner taking it for a fishing line laid hold of it and drew it in about fifteen fathoms. It was buoyed up by small pieces of wood tied to it at stated distances. At the end of the rope, a machine was fastened, too heavy for one man to pull up, for it exceeded 100 pounds in weight. The other people at the schooner, coming to his assistance, drew it on the deck. While the men were examining the machine, about five minutes from the time the wheel had been put in motion, it exploded, blew the vessel into pieces, and set her on fire. Three men were killed and the fourth blown into the water, much injured. On examining round the ship after this incident, the other part of the line was discovered buoyed up in the same manner. This, the Commodore ordered to be instantly cut away, for fear of hauling up another of the infernals, as he termed it. These machines were constructed with wheels, furnished with irons sharpened at the end and projecting about an inch in order to strike the sides of the vessel when hauling them up, thereby setting the wheels in motion, which in the space of five minutes caused the explosion. Had the whole apparatus been brought to operate on a ship at the time, it must have occasioned prodigious destruction. Then in January, 1778, Bushnell launched a salvo of floating mines down the Delaware River, hoping that they would contact and destroy British ships anchored in Philadelphia Harbor. However, the British had arranged their ships to avoid being struck by floating river ice, and this in turn protected them from the mines. The only casualties of the attack were two young boys who stumbled upon a mine and were killed in the resulting explosion. Nonetheless, the attack caused great consternation among the British forces, which were lampooned in a humorous ballad by composer Francis Hopkinson titled The Ballad of the Kegs. "'Twas early day, as poets say, just when the sun was rising, a soldier stood on a log of wood and saw a thing surprising. As in a maze he stood to gaze, the truth can't be denied, sir. He spied a score of kegs, or more, come floating down the tide, sir. A sailor, too, in jerkin' blue, the strange appearance viewing, first damned his eyes in great surprise, then said some mystery brewing. These kegs, I'm told, the rebels hold, packed up like pickled herring, and they've come down to tack the town in this new way of ferrying. The soldier flew, the sailor too, and scared almost to death, sir, wore out the shoes to spread the news, and ran till out of breath, sir." Following this failed attack, both the Connecticut government and the Continental Army refused to fund further work on mines or other underwater explosives. Instead, General Washington commissioned David Bushnell as a Captain Lieutenant in the U.S. Army Corps of Engineers, in which he served with distinction. Following the end of the Revolutionary War, Bushnell slipped into obscurity, moving first to France and then to Warrington, Georgia, where he worked as a schoolteacher and studied and practiced medicine until his death in 1824. Though his inventions had little impact on the course of the war, Bushnell was nonetheless widely admired and respected by his superiors, with George Washington stating in a 1785 letter to Thomas Jefferson, Bushnell is a man of great mechanical powers, fertile of invention, and a master in execution. He came to me in 1776, recommended by Governor Trumbull, now dead, and other respectable characters, who were proselytized to his plan. Although I wanted faith myself, I furnished him with money and other aids to carry it into execution. He labored for some time ineffectually, and though the advocates for his scheme continued sanguine, he never did succeed. One accident or another was always intervening. I then thought, and still think, that it was an effort of genius, but that a combination of too many things were requisite to expect much success from the enterprise against an enemy who are always upon guard. That he had a machine which was so contrived as to carry a man underwater at any depth he chose, and for a considerable time and distance, with an apparatus charged with powder which he could fasten to a ship's bottom or side, and give fire to in any given time sufficient for him to retire by means whereof a ship could be blown up or sunk, are facts which I believe admit of little doubt. But then, where it was to operate against an enemy, it is no easy matter to get a person hardy enough to encounter the variety of dangers to which he must be exposed, one, from the novelty, two, from the difficulty of conducting the machine and governing it underwater on account of the currents, and three, the consequent uncertainty of hitting the object of destination without rising frequently above water for fresh observation which, when near the vessel, would expose the adventurer to discovery and almost to certain death. To these causes I always ascribed the non-performance of his plan, as he wanted nothing that I could furnish to secure the success of it. This to the best of my recollection is a true state of the case. Indeed, while the basic concept of the Turtle was sound, Bushnell was limited by the technology of his day. Human muscle power alone was insufficient to counter the strong currents and other forces encountered under real combat conditions, while the need to manipulate several controls at once quickly grew overwhelming for even the most experienced operator. And without a means of storing or generating extra oxygen and absorbing carbon dioxide, the Turtle's submerged endurance was highly limited. In future submarines, all these various functions would be divided among multiple crewmen, greatly easing the operation of the vessel. Interestingly, some historians suggest that the Turtle, as described by Bushnell, was never actually used in combat, and that the entire story was either propaganda, or that the 1776 attack on HMS Eagle was carried out using a covered rowboat and not a true submersible. Whatever the case, today David Bushnell is widely regarded as the father of the combat submarine, with two U.S. Navy submarine tenderships being named in his honor, one in 1915 and one in 1942. But it would be another century before a submarine finally succeeded in sinking an enemy vessel in combat. On the evening of February 17, 1864, CSS H.L. Hunley attacked the Union Scoop of War, USS Housatonic, one of dozens of ships blockading the harbor at Charleston, South Carolina. Powered by a long hand crank, driven by seven men, the Hunley carried a 61 kg spar torpedo, the metal canister of gunpowder fitted with a barbed harpoon head, and fitted to the end of a seven meter long pole. The torpedo was designed to be rammed into the side of the target ship, whereupon the submarine would retreat to a safe distance and pull a long cord attached to the firing mechanism, setting off the charge. While the mission was successful, the Hunley and her crew were never heard from again, the wreck not being discovered until 1995. Though crude and highly dangerous like her predecessor the Turtle, the Hunley nonetheless provided naval planners with a tantalizing glimpse of what was to come.